Trends and inequities in colorectal cancer screening participation in Ontario,Canada, 2005–2011

Background: Participation in screening tests for colorectal cancer (CRC) is generally low in Ontario, Canada. In addition, inequities in participation exist including lower participation among low-income individuals, males and individuals living in rural areas. In April 2008, Colon Cancer Check (CCC) program, the province-wide CRC screening program, was launched in Ontario. This study describes the trends and inequities in CRC screening participation three years before and three years after the CCC, and assesses the effect of the program on CRC screening participation, overall and among certain population groups. Methods: We used administrative data to identify cohorts of individuals eligible for CRC screening in fiscal years 2005–2011. We calculated the age-standardized percent of Fecal Occult Blood Test (FOBT) participation, large bowel endoscopy participation, and being ‘up-to-date’ with CRC screening tests. Results: From 2005 to 2011, FOBT participation increased from 7.6% to 14.8%, large bowel endoscopy participation from 3.4% to 5.7%, and ‘up-to-date’ with CRC screening from 27.2% to 41.3%. Before the launch of the CCC program, the quarterly increase in FOBT participation was 0.07% (p = 0.19), increased immediately after the launch (1.8%, p < 0.01), followed by a decline (?0.08%, p = 0.08), returning to its pre-program increase rate. We noted a significant decrease in FOBT participation every summer (?0.44%, p < 0.01). The CCC program had minimal effect on large bowel endoscopy participation. Before the launch of the CCC program, the quarterly increase in ‘up-to-date’ with CRC screening was 0.9% (p < 0.01), increased immediately after the launch (2.5%, p = 0.05), followed by a modest decline thereafter (?0.59%, p < 0.02). From 2005 to 2011, recent residents living in low-income neighborhoods were consistently and significantly less likely to have a FOBT and be ‘up-to-date’ with CRC screening than long-term residents living in high-income neighborhoods (2.9–4.5%; 14.7–17.3% respectively). Pre-CCC inequities in CRC participation persisted after the launch of the program. Conclusion: CRC testing was increasing in Ontario from 2005. An immediate increase in CRC testing, FOBT in particular, occurred after the launch of the CCC program, followed by a return to its pre-CCC increase rate thereafter. Future efforts are needed to improve screening participation and address inequities.     

Community-based colorectal cancer intervention in underserved Korean Americans

Background: Despite evidence of a decline in both incidence and prevalence of colorectal cancer nationwide, it remains the second most commonly diagnosed cancer and the third highest cause of mortality among Asian Americans, including Korean Americans. This community-based and theoretically guided study evaluated a culturally appropriate intervention program that included a bilingual cancer educational program among Korean Americans including information on CRC risks, counseling to address psychosocial and access barriers, and patient navigation assistance. Methods: A two-group quasi-experimental design with baseline and post-intervention assessment and a 12-month follow-up on screening was used in the study. Korean Americans (N = 167) were enrolled from six Korean churches. The intervention group received culturally appropriate intervention program addressing accessibility and psychosocial barriers, and navigation assistance for screening. The control group received general health education that included cancer-related health issues and screening. Results: There was a significant difference (p < 0.05) between the post-intervention and control groups in awareness of CRC risk factors. There was also a significant improvement in the pre–post across HBM measures in the intervention group for perceived susceptibility (p < 0.05) and benefits and barriers to screening (p < 0.001). At baseline, 13% of participants in the intervention group and 10% in control group reported having had a CRC cancer screening test in the previous year. At the 12-month post-intervention follow-up, 77.4% of participants in the intervention group had obtained screening compared to 10.8% in the control group. Conclusion: While health disparities result from numerous factors, a culturally appropriate and church-based intervention can be highly effective in increasing knowledge of and access to, and in reducing barriers to CRC screening among underserved Koreans.     

Knowledge,perception and practices of colorectal cancer screening in an ethnically diverse population

Background: Colorectal cancer (CRC) screening improves survival and its success depends on the participation of the at-risk population. Few studies have adequately assessed screening knowledge, perception and participation according to birthplace. This study assesses the knowledge and perception of CRC in an ethnically diverse population, and evaluates the association with screening participation and intention. Identification of specific predictors of screening may aid the development of interventions to improve overall CRC screening. Methods: An interview-based survey, conducted on subjects aged 30–70 years, assessed knowledge and perception towards CRC and screening tests. Primary endpoints were screening participation and intent. Statistical methods used were Chi-square, Mann–Whitney U and logistic regression. Results: A total of 543 subjects (43% males, 53% Australian-born (AB), 63% aged 50 years and above) were recruited. Compared with AB, non-Australian-born (NAB) respondents had poorer knowledge, and NAB background predicted for poorer knowledge independent of sex, education, media and familiarity with CRC patient. Compared with AB respondents aged 50 years and above, NAB respondents had lower screening participation (17.4% vs. 31.8%; P = 0.01), lesser intention (75.8% vs. 90.5%; P < 0.001), and had received fewer doctors’ screening recommendations (16.5% vs. 27.1%; P = 0.04). In multivariate analysis, doctors’ recommendation, media and improved perception independently predicted screening participation; knowledge and media exposure predicted intent. Conclusions: The knowledge of CRC and screening is significantly poorer in the immigrant population. Knowledge predicts for greater screening intent. Therefore, implementing language- and culture-specific educational programs involving medical practitioners and media are necessary to improve CRC screening participation rates.     

Diabetes,metformin use,and colorectal cancer survival in postmenopausal women

Background: Observational studies have associated metformin use with lower colorectal cancer (CRC) incidence but few studies have examined metformin's influence on CRC survival. We examined the relationships among metformin use, diabetes, and survival in postmenopausal women with CRC in the Women's Health Initiative (WHI) clinical trials and observational study. Methods: 2066 postmenopausal women with CRC were followed for a median of 4.1 years, with 589 deaths after CRC diagnosis from all causes and 414 deaths directly attributed to CRC. CRC-specific survival was compared among women with diabetes with metformin use (n = 84); women with diabetes with no metformin use (n = 128); and women without diabetes (n = 1854). Cox proportional hazard models were used to estimate associations among metformin use, diabetes and survival after CRC. Strategies to adjust for potential confounders included: multivariate adjustment with known predictors of colorectal cancer survival and construction of a propensity score for the likelihood of receiving metformin, with model stratification by propensity score quintile. Results: After adjusting for age and stage, CRC specific survival in women with diabetes with metformin use was not significantly different compared to that in women with diabetes with no metformin use (HR 0.75; 95% CI 0.40–1.38, p = 0.67) and to women without diabetes (HR 1.00; 95% CI 0.61–1.66, p = 0.99). Following propensity score adjustment, the HR for CRC-specific survival in women with diabetes with metformin use compared to non-users was 0.78 (95% CI 0.38–1.55, p = 0.47) and for overall survival was 0.86 (95% CI 0.49–1.52; p = 0.60). Conclusions: In postmenopausal women with CRC and DM, no statistically significant difference was seen in CRC specific survival in those who used metformin compared to non-users. Analyses in larger populations of colorectal cancer patients are warranted.     

Socioeconomic and healthcare supply statistical determinants of compliance to mammography screening programs: A multilevel analysis in Calvados,France

Background: Although the literature on factors associated with mammography screening is abundant, reasons for underparticipation remain unclear, most studies having focused exclusively on individual factors. This study aimed at investigating the ecological influence of socioeconomic status and healthcare supply on compliance to organized breast cancer screening programs, on an unbiased sample based on data from the entire target population within a French geographical area, Calvados (n = 98,822 women). Methods: Individual data on participation and aggregate data on healthcare supply and socioeconomic status, respectively obtained from the structure responsible for organizing screening and the French census, were analyzed simultaneously using a multilevel model. Results: Uptake was lower among the youngest (50–54 years) and the oldest (70–74 years) women, compared to the intermediate 55–69 year age-group, with respectively OR = 0.73 (95%CI: 0.64–0.83) and OR = 0.78 (95%CI: 0.67–0.91). Uptake fell with increasing level of deprivation, a difference in uptake probability being observed between the least deprived and the most deprived areas (OR = 0.71; 95%CI: 0.59–0.86). Neither radiologist- nor primary care physicians-to-100,000 inhabitants ratios were associated with participation. Conclusions: Multilevel analysis allows to detect areas of weak participation statistically linked to areas of strong deprivation. So, even with organized breast cancer screening giving screening free of charge for target women, ecological socioeconomic factors have a more significant impact on participation than healthcare supply. These results suggest that targeting populations, in accurate geographical areas where women are less likely to participate, as identified socially and geographically in this study, could be adopted to reduce disparities in screening.     

Impact of an educational video-based strategy on the behavior process associated with colorectal cancer screening: A randomized controlled study

Background: Low public awareness is an important barrier for colorectal cancer screening participation. Aim: To evaluate the impact of educational intervention on the health behavior process, patient knowledge and compliance with colorectal cancer screening in the average-risk population. Methods: 158 subjects (aged 50–79 years) were randomly assigned either to watch a non-medical video or a colorectal cancer educational video. Before and after watching the experimental or control videotape, participants completed a five-item questionnaire that assessed their knowledge about risk factors for colorectal cancer, age of risk, warning symptoms, 5-year prognosis, and incidence. Subjective risk perception for developing colorectal cancer, barriers or benefits of screening, and intention to be screened were also investigated. Finally, subjects received a faecal occult blood test kit and were requested to use and return it within 2 weeks. Results: Participants in the video-based intervention group showed significant improvement in knowledge of colorectal cancer scores (P < 0.001) and decreased barrier scores. The intervention group returned significantly more faecal occult blood tests than controls (69.6% vs. 54.4%, P = 0.035). The intervention had a positive effect on modifying attitudes and intention to take part in screening. Additionally, the intervention was a predictor of compliance (OR 2.0; 95% CI = 1.02–3.84, P = 0.044). Conclusion: Video-based intervention significantly reduced barriers to screening and improved participant awareness and compliance with colorectal cancer screening with faecal occult blood test.     

Ethnic differences and predictors of colonoscopy,prostate-specific antigen,and mammography screening participation in the multiethnic cohort

PurposeGiven the relation between screening and improved cancer outcomes and the persistence of ethnic disparities in cancer mortality, we explored ethnic differences in colonoscopy, prostate-specific antigen (PSA), and mammography screening in the Multiethnic Cohort Study.MethodsLogistic regression was applied to examine the influence of ethnicity as well as demographics, lifestyle factors, comorbidities, family history of cancer, and previous screening history on self-reported screening participation collected in 1999–2002.ResultsThe analysis included 140,398 participants who identified as white, African American, Native Hawaiian, Japanese American, US born-Latino, or Mexican born-Latino. The screening prevalences overall were mammography: 88% of women, PSA: 45% of men, and colonoscopy: 35% of men and women. All minority groups reported 10–40% lower screening utilization than whites, but Mexican-born Latinos and Native Hawaiian were lowest. Men were nearly twice as likely to have a colonoscopy (OR = 1.94, 95% CI = 1.89–1.99) as women. A personal screening history, presence of comorbidities, and family history of cancer predicted higher screening utilization across modalities, but to different degrees across ethnic groups.ConclusionsThis study confirms previously reported sex differences in colorectal cancer screening and ethnic disparities in screening participation. The findings suggest it may be useful to include personal screening history and family history of cancer into counseling patients about screening participation.     

Germline HOXB13 p.Gly84Glu mutation and risk of colorectal cancer

Introduction: The HOXB13 pGly84Glu mutation has recently been associated with an increased risk of prostate cancer but the association of other cancer sites with this allele has not been assessed. Data has suggested that HOXB13 expression levels are decreased in colorectal cancer (CRC) cell lines indicating this gene may be involved in colorectal tumourigenesis. Methods: To evaluate a potential association of this mutation with CRC, we genotyped the mutation in 2695 CRC cases and 4593 controls from population-based registries in Canada and Australia. Results: The HOXB13 pGly84Glu mutation was more common in CRC cases than controls (0.48% vs. 0.17%, P = 0.02) indicating a significant association between the HOXB13 variant and CRC risk (OR = 2.8; 95%CI: 1.2–6.8). This association was attenuated but remained significant with the inclusion of previously published and publicly available genotype data. Pedigree analysis of cases and controls revealed that 7/21 HOXB13 mutation carriers had a family history of prostate cancer. Discussion: This report is the first to suggest a risk of CRC associated with mutations in the HOXB13 gene. These findings require further validation but may be of importance in the screening and genetic counseling of families known to carry the HOXB13 pGly84Glu mutation.     

10-Year risk of colorectal cancer: Development and validation of a prediction model in middle-aged Japanese men

Background: To estimate an individual's probability of developing colorectal cancer (CRC) may aid health professionals and individuals in improving lifestyle behaviors or deciding the screening regimens. As fewer studies on cancer risk prediction were seen so far, we initially developed an assessment tool with synthesizing key information from a variety of CRC risk factors through a large population-based cohort study. Method: The prediction model was derived from 28,115 men in the Japan Public Health Center-based (JPHC) Prospective Study Cohort II (follow-up: 1993–2005), with risk factors selected by Cox proportion hazard regression. 18,256 men in the JPHC Study Cohort I (follow-up: 1995–2005) were used to evaluate the model's performance. Results: 543 and 398 CRCs were diagnosed during the follow-up period in Cohorts II and I, respectively. The prediction model, including age, BMI, alcohol consumption, smoking status, and the daily physical activity level, showed modest discrimination ability for CRC (C = 0.70; 95% confidential interval, 0.68–0.72) in Cohort II and well calibrated in Cohort I (Hosmer–Lemeshow χ² = 14.2, P = 0.08). Conclusion: The 10-year CRC risk prediction model may be used to estimate CRC risk in Japanese men. It may also play a role in the promotion of CRC prevention strategies.     

Provider recommendation for colorectal cancer screening: Examining the role of patients’ socioeconomic status and health insurance

Background: Provider recommendation for colorectal cancer (CRC) screening test has been shown as a strong predictor of patients’ decision to be screened. Evidence of factors associated with provider recommendation remains limited and inconsistent. The present study sought to examine the association between provider recommendation for colorectal cancer screening and patients’ socioeconomic status (SES) and insurance status using national survey data for 2005. Methods: Analyses were based on 2948 adult aged 50 and older who participated in the 2005 Health Information National Trend Survey (HINTS). Multivariate logistic regression models were used to determine whether the indicators of SES (income and educational level) and insurance status have any impact on provider recommendation. Results: Our study found a strong association between recall of health care provider recommendation and reported recent screening testing after controlling for other patient characteristics. When all the study population were included in the analysis, those who had lower than high school education and high school graduates were less likely to have received provider recommendation than those with higher than high school education (OR = 0.49; 95%CI = 0.32–0.73 and OR = 0.60; 95%CI = 0.47–0.78 respectively). Income and insurance were not significant predictors. Education remained significantly associated with provider recommendation when only those who had made one or more medical visits in the past year were included in the analyses. Conclusions: Patient's educational level – but not income or insurance status – was related to provider recommendation for CRC screening. To increase awareness of colorectal cancer risks and the benefit of screening, health care providers need to make a concerted effort to recommend colorectal cancer screening to all relevant patients, regardless of socioeconomic status and other personal characteristics.     

Time to diagnosis and stage of symptomatic colorectal cancer determined by three different sources of information: A population based retrospective study

BackgroundSurvival rates from colorectal cancer (CRC) are highly variable in Europe. This variability could potentially be explained by differences in healthcare system delays in diagnosis. However, even when such delays are reduced, the relationship of the diagnostic interval (time from presentation with symptoms to diagnosis) with outcome is uncertain.MethodsA total of 795 patients with CRC from 5 regions of Spain were retrospectively examined in this population-based multicenter study. Consecutive incident cases of CRC were identified from pathology services. The total diagnostic interval (TDI) was defined as the time from the first presentation with symptoms to diagnosis based on 3 different sources of information: (i) patient-recorded data (PR-TDI) by interview, (ii) hospital-recorded data (HR-TDI), and (iii) general practitioner-recorded data (GPR-TDI). Concordance correlation coefficients (CCCs) were used to estimate the agreement of 3 different TDIs. The TDIs of patients with different stages of CRC were also compared using the Kruskal-Wallis test.ResultsThe median TDI was 131 days based on patient interview data, 91 days based on HR data, and 111 days based on GPR data. Overall, the agreement of these TDIs was poor (CCC_PRvsHR = 0.399, CCC_PRvsGPR = 0.518, CCC_HRvsGPR = 0.383). Univariate analysis indicated that the TDI was greater in those with less advanced CRC for all 3 methods of calculation, but this association was only statistically significant for the HR-TDI (p = 0.021).ConclusionThere is no evidence that patients with more advanced CRC have longer TDIs. In fact, we found an inverse relationship between the TDI and CRC stage, an example of the “waiting time paradox”. This association may likely be due to the presence of unmeasured confounders as the stage when symptoms appear or the tumour aggressiveness.     

Body mass index and screening for colorectal cancer: gender and attitudinal factors

Background: Overweight/obese women and men are at increased risk for colorectal cancer (CRC) incidence and mortality. Research examining body mass index (BMI) and CRC screening has had mixed results. A clearer understanding of the extent to which high-BMI subgroups are screened for CRC is needed to inform planning for CRC screening promotions targeting BMI. Methods: Data were obtained from a random, population-based sample of women and men at average-risk for CRC (aged 50–75 years) during 2004 (n = 1098). Multiple logistic regression analyses were conducted to evaluate whether BMI category was significantly associated with the probability of reporting recent CRC screening and with the probability of agreeing with statements denoting attitudes/perceptions about CRC and screening. Attitudes/perceptions about CRC and screening were evaluated as potential mediators and moderators of the association between BMI category and CRC screening. Results: After controlling for characteristics associated with CRC screening, overweight and obese women were each 40% less likely to have CRC screening than women with normal-BMI (OR = 0.6, 95% CI:0.4–0.9 and OR = 0.6, 95% CI:0.3–0.9). BMI category was unrelated to screening among men. Obese women (but not men) were less aware than normal-BMI women that obesity increased risk for CRC (OR = 0.5, 95% CI:0.3–0.9) and less worried about CRC (OR = 0.5, 95% CI:0.3–0.8). However, findings suggest that attitudes/perceptions about CRC and screening did not mediate or moderate the association between BMI category and CRC screening. Conclusion: Overweight/obese women are at increased risk for CRC because of their greater BMI and their propensity not to screen for CRC. Study findings suggest that potentially modifiable perceptions, e.g., lack of awareness of risk for CRC and less worry about CRC, in this subgroup may not explain the relationship between BMI category and reduced screening.     

Association between family history of malignant neoplasm with colorectal adenomatous polyp in 40s aged relative person

PurposeWe assessed the association between a family history of malignancy and risk of colorectal adenoma among individuals aged 40–49 years.MethodsThe study population consisted of subjects, aged in their 40s, who underwent colonoscopy. Their family histories of cancer were collected with a self-administered questionnaire. A logistic regression model was used to assess the association between a family history of cancer and the risk of colorectal polyp.ResultsIn total, 2275 participants were included in the study. Univariate analysis showed that old age, male sex, current cigarette smoking, BMI > 25 kg/m², and a family history of colorectal cancer (CRC) were risk factors for the development of sporadic colorectal adenomatous polyps in these patients. A multivariate analysis showed that a family history of CRC or kidney cancer was associated with adenoma development. A family history of CRC was also a risk factor for advanced and multiple adenoma.ConclusionsThis study shows that a family history of CRC is a risk factor for advanced and multiple colorectal adenoma in people in their 40s. These results support earlier screening for colorectal neoplasms in individuals with a family history of CRC.     

Breast cancer detection risk in screening mammography after a false-positive result

Background: False-positives are a major concern in breast cancer screening. However, false-positives have been little evaluated as a prognostic factor for cancer detection. Our aim was to evaluate the association of false-positive results with the cancer detection risk in subsequent screening participations over a 17-year period. Methods: This is a retrospective cohort study of 762,506 women aged 45–69 years, with at least two screening participations, who underwent 2,594,146 screening mammograms from 1990 to 2006. Multilevel discrete-time hazard models were used to estimate the adjusted odds ratios (OR) of breast cancer detection in subsequent screening participations in women with false-positive results. Results: False-positives involving a fine-needle aspiration cytology or a biopsy had a higher cancer detection risk than those involving additional imaging procedures alone (OR = 2.69; 95%CI: 2.28–3.16 and OR = 1.81; 95%CI: 1.70–1.94, respectively). The risk of cancer detection increased substantially if women with cytology or biopsy had a familial history of breast cancer (OR = 4.64; 95%CI: 3.23–6.66). Other factors associated with an increased cancer detection risk were age 65–69 years (OR = 1.84; 95%CI: 1.67–2.03), non-attendance at the previous screening invitation (OR = 1.26; 95%CI: 1.11–1.43), and having undergone a previous benign biopsy outside the screening program (OR = 1.24; 95%CI: 1.13–1.35). Conclusion: Women with a false-positive test have an increased risk of cancer detection in subsequent screening participations, especially those with a false-positive result involving cytology or biopsy. Understanding the factors behind this association could provide valuable information to increase the effectiveness of breast cancer screening.     

Predictors of non-participation in cervical screening in Denmark

PurposeThe aims of this study were to identify demographic and socio-economic predictors of non-participation in cervical screening in Denmark, and to evaluate the influence of health care use on screening participation.MethodsA population based register study was undertaken using data from the Central Population Register, the national Patobank, and Statistics Denmark. The study included women aged 25–54 years on 1st of January 2002, living in Denmark during the next 5 years, and without a history of total hysterectomy, N = 1,052,447. Independent variables included age, civil status, nationality, level of education, and use of health care. Associations with non-participation in screening were determined with logistic regression.ResultsMain predictors of non-participation were limited or no contact with dental services (odds ratio (OR) = 2.36), general practitioners (OR = 1.75), and high age (OR = 1.98). Other important factors for non-participation were primary school education only (OR = 1.53), not being married (OR = 1.49), and foreign nationality (OR = 1.32).ConclusionA 2–1.5-fold difference in non-participation in cervical screening in Denmark was found across various population sub-groups. Increased screening compliance among women with primary school education only, and limited or no use of primary health care services in general could potentially diminish the current social inequalities in cervical cancer incidence, and thus decrease the overall high incidence of this disease in Denmark.     

The functional −94 insertion/deletion ATTG polymorphism in the promoter region of NFKB1 gene increases the risk of sporadic colorectal cancer

Objective: To investigate the allele and genotype frequencies of NFKB1 ?94 ins/del ATTG (rs28720239) polymorphism and to evaluate the association between the polymorphism and colorectal cancer (CRC) risk in Malaysian population. Methods: Genomic DNA was extracted from the peripheral blood samples of 474 study subjects, which consisted of 237 histopathologically confirmed CRC patients and an equal number of cancer-free controls. The NFKB1 ?94 ins/del ATTG (rs28720239) polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and confirmed by DNA sequencing. The association between the polymorphic genotypes and CRC risk was evaluated by deriving odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis. Results: The frequencies of wildtype (del/del), heterozygous (del/ins) and variant (ins/ins) genotypes in CRC patients were 31.7%, 53.6% and 14.8%, respectively, while those in cancer-free controls were 35.0%, 58.2% and 6.8%, respectively. The frequency of the variant genotype was significantly higher in cases compared to controls (P < 0.01). Evaluation of the risk association of the polymorphic genotypes revealed that the variant genotype could contribute to a significantly increased risk of CRC (OR = 2.42, 95% CI = 1.24–4.73, P < 0.01). Conclusions: The variant allele of NFKB1 ?94 ins/del ATTG (rs28362491) polymorphism is associated with higher risk of sporadic CRC in Malaysian population.     

No association between garlic intake and risk of colorectal cancer

BackgroundAlthough experimental studies suggested beneficial role of garlic intake on colorectal carcinogenesis, limited prospective cohort studies have evaluated garlic intake in relation to colorectal cancer (CRC) incidence.MethodsWe followed 76,208 women in the Nurses’ Health Study and 45,592 men in the Health Professionals Follow-up Study for up to 24 years and examined garlic intake and garlic supplement use in relation to CRC risk. Information on garlic intake and supplement use was assessed using a validated food frequency questionnaire and a Cox proportional hazard regression model was used to estimate the multivariable hazard ratio (MV-HR) and 95% confidence intervals (95% CIs).ResultsWe documented 2368 (1339 women and 1029 men) incident CRC cases and found no association between garlic intake and CRC risk; the MV-HRs (95% CIs) associated with garlic (1 clove or 4 shakes per serving) intake ≥1/day compared with <1/month were 1.21 (0.94–1.57; p-trend = 0.14) for women and 1.00 (0.71–1.42; p-trend = 0.89) for men. The MV-HRs (95% CIs) of CRC for garlic supplement use, which was used in 6% of the participants in each study, were 0.72 (0.48–1.07) for women and 1.22 (0.83–1.78) for men.ConclusionOur prospective data do not support an important role of garlic intake or garlic supplement use in colorectal carcinogenesis.     

Clinical and radiological features of breast tumors according to history of false-positive results in mammography screening

BackgroundWomen with a false-positive result after a screening mammogram have an increased risk of cancer detection in subsequent participations, especially after assessments involving cytology or biopsy. We aimed to compare women's personal characteristics, tumoral features and the radiological appearance of cancers with and without a previous false-positive result generated by additional imaging or invasive procedures.MethodsFrom 1996 to 2007, 111,098 women aged 45–69 years participated in four population-based breast cancer screening programs in Spain, and 1281 cancers were detected. We included all cancers detected in subsequent screenings (n = 703) and explored the occurrence of previous false-positive results. We identified false-positives requiring additional imaging or invasive procedures. Differences on tumoral features (invasiveness, tumor size, and lymph node status) and radiological appearance were assessed by Chi-square test, and agreement between the location of cancer and prior suspicious by Cohen's kappa coefficient. A multivariate analysis was preformed to evaluate the effect of previous screening results and age on the odds of presenting an in situ carcinoma.ResultsAmong the 703 cancers detected in subsequent screenings, 148 women (21.1%) had a previous false-positive result. Of these, 105 were by additional imaging and 43 by invasive procedures. Women with prior false-positive result requiring invasive assessment, compared to women with negative tests, and women with prior false-positive requiring additional imaging, had a higher proportion of in situ carcinomas (31.7%, 15.3%, 12.9%, respectively; p = 0.014) and microcalcifications (37.2%, 20.2%, 9.5%, respectively; p = 0.003). The proportion of in situ carcinomas was even higher in women over 60 years (39.2%, 12.5%, 13.0%, respectively; p = 0.001). Ipsilateral cancer was observed in 65.7% of cases with prior cytology or biopsy (k = 0.479; 95%CI: 0.330–0.794).ConclusionA large number of in situ malignancies and calcification patterns were found among women with prior false-positive result in mammography screening requiring cytology or biopsies, suggesting progression from a previously benign lesion.     

Glutathione S-transferase polymorphisms and survival in African-American and White colorectal cancer patients

Background: Glutathione S-transferase (GST) enzymes are involved in electrophile detoxification. The authors investigated the association between GST genotype and survival in a racially diverse, population-based cohort of colorectal cancer (CRC) patients followed for a median of 9.6 years. Methods: Interviews were conducted with 315 African-American and White CRC patients in Connecticut, 1987–1991. Tumor tissue (n = 197) was later retrieved from hospital of diagnosis and assayed using multiplex PCR (GSTM1 and GSTT1) and PCR and RFLP analysis (GSTP1). Cox proportional hazards models provided adjusted hazard ratios (HR) and 95% confidence intervals (CI). Results: Individuals with Ile/Val or Val/Val GSTP1 genotypes had a decreased risk of death (multivariate adjusted HR = 0.72, 95% CI: 0.48, 1.09) relative to those with wild type (Ile/Ile). Among those who received chemotherapy, this benefit was more pronounced (HR = 0.35, 95% CI: 0.16, 0.79); the interaction of reduced function GSTP1 genotype and chemotherapy was significant (P = 0.05). GSTM1 and GSTT1 genotype were not associated with survival. GSTM1, GSTT1, and GSTP1 genotype did not vary by race and did not contribute significantly to the survival disadvantage observed in African-Americans. Conclusions: In summary, GSTP1 genotype may play a role in CRC survival in African-Americans and Whites, particularly among those who receive chemotherapy.     

Serum pepsinogen level,atrophic gastritis and the risk of incident pancreatic cancer—A prospective cohort study

Background: Pancreatic cancer is a highly fatal disease without screening tests. Studies have suggested possible etiologic similarities between gastric and pancreatic cancers. Atrophic gastritis, a pre-malignant condition for gastric cancer, is characterized by low serum pepsinogen I (SPGI) level. We hypothesized that low SPGI level may be associated with an increased risk of pancreatic cancer and be a useful biomarker for the disease. Methods: Our analytic cohort included 20,962 participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) who had SPGI level measured. Of these, 1663 (7.9%) subjects had low SPGI levels (<25 μg/l) and were invited for gastroscopy which was completed in 1059 (63.7%) participants. Atrophic gastritis was histologically confirmed in 1006 (95.0%) subjects. We used Cox proportional hazards regression to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for pancreatic cancer. Results: During follow-up of up to 16.3 years (mean = 10.8 years; 226,325 person-years), 227 incident pancreatic cancers were diagnosed. The incidence rates were 9.9, 11.3, and 12.7 per 10,000 person-years of follow-up for participants with normal pepsinogen level (≥25 μg/l), low pepsinogen level and histologically confirmed atrophic gastritis, respectively. Compared to subjects with normal pepsinogen levels, there was no statistically significant increased risk of pancreatic cancer among subjects with low pepsinogen level (adjusted HR = 1.01; 95% CI: 0.63–1.62) or those with histologically confirmed atrophic gastritis (adjusted HR = 1.13; 95% CI: 0.66–1.95). Conclusions: Atrophic gastritis, serological or histological, is not associated with increased risk of pancreatic cancer. These findings do not provide any evidence for potential usefulness of SPGI for pancreatic cancer screening.