Augmentation mammaplasty and breast cancer: a 5-year update of the Los Angeles study.

We have previously reported on the risk of breast cancer in women during the first few years following cosmetic augmentation mammaplasty and are now presenting results after longer exposure. Long-term carcinogenicity of breast implants in humans has not been assessed previously. We conducted a retrospective cohort study of 3112 patients with a median of 10.6 years of postimplant experience (range 0.1 to 31.7 years). Patients were enrolled from surgeons' records, and cancer outcomes were monitored by the population-based cancer registry serving Los Angeles County. Because of confidentiality concerns, there was no direct patient contact. Twenty-one breast cancers were observed among the implant patients as compared with 31.7 expected, based on Los Angeles County incidence rates [standardized incidence ratio (SIR) = 66 percent, 95 percent confidence limits (CL): 41 percent, 101 percent]. For all other malignancies combined, 45 were observed and 50.0 were expected (SIR = 90 percent, CL: 66 percent, 120 percent). Although the numbers of cases were very small, increased frequencies of lung and vulvar cancers were observed. Based on the evidence to date, we conclude that there is no increase in breast cancer incidence following augmentation mammaplasty.     

Breast cancer following breast reduction surgery in Sweden

Women undergoing breast reduction surgery have been reported to be at low subsequent risk of breast cancer, especially when the surgery is performed after age 40. To evaluate the age and time-related patterns of cancer risk following surgical removal of breast tissue, we identified 31,910 women who underwent breast reduction surgery from 1965 to 1993 in Sweden using hospital discharge register data. There were 19,975 women (63 percent) under age 40 at surgery. Linkages with Swedish registries for cancer, death, and emigration were based on unique national registration numbers assigned to each Swedish resident. Cancer incidence was contrasted with that expected in the general population based on age- and calendar year-specific data from the nationwide cancer registry. Overall, 161 incident breast cancers were identified during 238,765 person-years of observation (mean, 7.5 years) compared with 223.9 expected (standardized incidence ratio = 0.72; 95 percent confidence interval = 0.61 to 0.84). The reduction in risk of breast cancer was most pronounced for women whose operations were performed after age 50 (SIR = 0.57) and for those followed for more than 5 years (SIR = 0.68). Among women operated on before age 40, risk was nonsignificantly elevated within the first 5 years after surgery (SIR = 1.47; 95 percent CI = 0.89 to 2.30) but tended to be reduced thereafter (SIR = 0.80; 95 percent CI = 0.55 to 1.13). The magnitude of the reduction in risk thus appears directly related to age at surgery. Women followed for an average of 7.5 years after bilateral breast reduction surgery, were at a statistically significant 28 percent decreased risk of breast cancer. The current study is thus consistent with a protective effect following partial removal of breast glandular tissue.     

Are infertility treatments a potential risk factor for cancer development? Perspective of 30 years of follow-up

The aim of the present study was to evaluate the possible risk for cancer development in infertile women with over 30 years of follow-up. Cancer development was assessed through linkage with the National Cancer Registry updated to 31 December 2005 in a cohort of 2431 women who were treated for infertility at the Sheba Medical Center in Israel during the period 1964-1974 and contributed more than 84,000 women years of follow-up. Standardized incidence ratios (SIR) were calculated between the observed cancer cases and the expected cancer rates in the general population. The mean age at the end of follow-up was 62.7 years. Eighteen cases of ovarian cancer were observed as compared to 18.1 expected (SIR = 1.0; 95% CI = 0.59-1.57). For breast cancer, 153 cases were observed as compared to 131.9 expected (SIR = 1.16; 95% CI = 0.98-1.36), and for endometrial cancer, 30 cases were observed as compared to 17.8 expected cases (SIR = 1.69; 95% CI = 1.14-2.41). No excess risk associated with exposure to gonadotropins was observed. Infertility was found to be associated with significant increased risk for endometrial cancer and borderline increased risk for breast cancer. Ovarian cancer risk was not found to be elevated. No significant excess risk was associated with treatment with ovulation induction.     

A cohort study of breast cancer risk in breast reduction patients.

Surgical reduction of the female breast (reduction mammaplasty) is very common in plastic surgery. The purpose of this study was to determine whether women who have undergone breast reduction surgery are at the same, greater, or lesser risk of developing breast cancer than women who have not undergone breast reduction surgery. This study incorporates a population-based, non-concurrent cohort linkage methodology. The Canadian Institute for Health Information hospital records were used to identify all Ontario women who had undergone breast reduction surgery in Ontario between 1979 and 1992. Three computerized probabilistic record linkages were performed. The first linkage was between a file of the 28,042 Ontario women who had undergone bilateral breast reduction surgery between April 1, 1979, and December 31, 1992, and a file of incident cancer cases among Ontario women for the calendar period 1979 to 1993. Follow-up of the cohort was undertaken starting from the date of breast reduction surgery, and vital status was ascertained as of December 31, 1993, by record linkage with the Ontario Mortality Database maintained at the Ontario Cancer Registry. The incidence of cancer in the Ontario breast reduction cohort was compared with the cancer incidence of the general Ontario population after appropriate adjustments for age and calendar time period. The expected number of cancers was calculated using the "PERSON YEARS" computer program. Within the cohort, followed for an average of 6.5 years after bilateral breast reduction surgery, 101 breast cancers were observed and 165.8 were expected, for a standardized incidence ratio of 0.61 (0.50 to 0.74, 95 percent confidence interval). This effect was independent of patient age at breast reduction. This study demonstrates that there is no increased risk of breast cancer after bilateral breast reduction surgery and, in fact, a significant decreased risk existed in women followed for an average of 6.5 years.     

Risk of cancer of the breast after legal abortion during first trimester: a Swedish register study.

An increase in induced abortions in Sweden has been accompanied by an increase in the incidence of breast cancer of about 40% in women aged 20-44. To assess whether the apparent risk is real the risk of breast cancer was investigated in practically all Swedish women with a history of a legal abortion in the first trimester before the age of 30 during 1966-74 (n = 49,000). The cohort was followed up in the Swedish cancer register to identify cases of breast cancer diagnosed more than five years after the abortion until the end of 1984. The number of observed cases of breast cancer was 65 compared with an expected number of 84.5, estimated from the contemporary Swedish population with due consideration to age, giving a relative risk of 0.8 (95% confidence interval 0.58 to 0.99). Contrary to most earlier reports, this study did not indicate any overall increased risk of breast cancer after an induced abortion in the first trimester in young women.     

Risk of primary haematologic cancers following incident non-metastatic breast cancer: A Danish population-based cohort study

BackgroundBreast cancer survivors may have increased risk of subsequent haematologic cancer. We compared their risk of haematologic cancers with the general population during 38 years of follow-up.MethodsUsing population-based Danish medical registries, we assembled a nationwide cohort of women diagnosed with incident non-metastatic breast cancer during 1980–2017, with follow-up through 2018. We compared breast cancer survivors with the general population by computing standardised incidence ratios (SIR) and 95% confidence intervals (CI).ResultsAmong 101,117 breast cancer survivors, we observed 815 incident haematologic cancers (median follow-up: 7.9 years). We observed excess risk of acute myeloid leukaemia (AML) (SIR: 1.65, 95%CI: 1.33–2.01), particularly in women who received chemotherapy (SIR: 3.33, 95%CI: 2.24–4.75) and premenopausal women (SIR: 3.23, 95%CI: 2.41–4.25). The risk of acute lymphoid leukaemia (ALL) was increased (SIR: 2.25, 95%CI: 1.29–3.66), whereas the risk of chronic lymphoid leukaemia (CLL) was decreased (SIR: 0.66, 95%CI: 0.53–0.82). An additional analysis showed elevated risk of CLL 0–6 months after breast cancer diagnosis (SIR: 3.00 95%CI: 1.75–4.80).ConclusionCompared to the general population, breast cancer survivors had elevated risk of AML, particularly when treated with chemotherapy. The risk of ALL was elevated, whereas the risk of CLL was lower. The higher risk of CLL in the first six months after diagnosis likely reflects surveillance bias—due to intensified diagnostic efforts at breast cancer diagnosis and treatment—prompting earlier detection. This has likely reduced the long-term risk of CLL in breast cancer survivors.     

Frequent chest X-ray fluoroscopy and breast cancer incidence among tuberculosis patients in Massachusetts

The incidence of breast cancer was determined in 4940 women treated for tuberculosis between 1925 and 1954 in Massachusetts. Among 2573 women examined by X-ray fluoroscopy an average of 88 times during lung collapse therapy and followed for an average of 30 years, 147 breast cancers occurred in contrast to 113.6 expected [observed/expected (O/E) = 1.29; 95% confidence interval (CI) = 1.1-1.5]. No excess of breast cancer was seen among 2367 women treated by other means: 87 observed versus 100.9 expected. Increased rates for breast cancer were not apparent until about 10 to 15 years after the initial fluoroscopy examination. Excess risk then remained high throughout all intervals of follow-up, up to 50 years after first exposure. Age at exposure strongly influenced the risk of radiation-induced breast cancer with young women being at highest risk and those over age 40 being at lowest risk [relative risk (RR) = 1.06]. Mean radiation dose to the breast was estimated to be 79 cGy, and there was strong evidence for a linear relationship between dose and breast cancer risk. Allowing for a 10-year minimum latent period, the relative risk at 1 Gy was estimated as 1.61 and the absolute excess as 10.7 per 10(4) woman-years per gray. When compared to other studies, our data suggest that the breast is one of the most sensitive tissues to the carcinogenic force of radiation, that fractionated exposures are similar to single exposures of the same total dose in their ability to induce breast cancer, that risk remains high for many years after exposure, and that young women are especially vulnerable to radiation injury.     

Physical and psychosocial symptoms among 88 volunteer subjects compared with patients seeking plastic surgery procedures to the breast

In an investigation of the relationship between macromastia and physical and psychosocial symptoms, 88 female university students, 21 augmentation mammaplasty patients, and 31 breast reduction patients graded somatic and psychosocial symptoms. The intent of the study was to discover which complaints were most common among women presenting for reduction mammaplasty and to determine whether height/weight index and brassiere chest measurement and cup size might affect their symptoms. Both the student group and the augmentation mammaplasty patients differed significantly from the breast reduction patients. Eighty-one percent of the reduction patients complained of neck and back pain. Seventy-seven percent complained of shoulder pain, 58 percent complained of chafing or rash; 45 percent reported significant limitation in their activity; and 52 percent were unhappy with their appearance (p < 0.001 compared with augmentation and student groups). Physical symptoms were related to height/weight index and bra chest and cup sizes in each of the three participating groups. It was found that patients who present for symptom-related reduction mammaplasty have a disease-specific group of physical and psychosocial complaints that are more directly related to large breast size than to being overweight.     

Carpal tunnel syndrome in women undergoing reduction mammaplasty

Women with mammary hypertrophy who present for reduction mammaplasty have several well-described musculoskeletal complaints, but a high prevalence of carpal tunnel syndrome has not been reported. We identified 151 patients from a plastic surgery practice who underwent reduction mammaplasty from 1994 to 1996. To this group we added a convenience sample of 64 women volunteers with relatively smaller breasts (brassiere cup size B or smaller). We questioned the entire group about specific symptoms and examined them using standard provocative tests. Carpal tunnel syndrome was defined as the coexistence of symptoms and at least two physical examination findings. We examined its association with breast size, age, race, and body mass index. Stepwise logistic regression was used to determine which physical characteristics were predictive of the condition. Carpal tunnel syndrome was found in 30 patients (19.9 percent) (95 percent confidence interval, 13.8 to 27.1) and in none of the women in the convenience sample. Breast size and, to a lesser degree, body mass index were found to be highly significant predictors of carpal tunnel syndrome. After controlling for breast size, race was also significant. Breast size displayed an independent risk ratio of 6.67 when comparing the upper quartile of size to the lower quartiles. There is a markedly higher prevalence of carpal tunnel syndrome in women who present for reduction mammaplasty than in those with smaller breasts. Breast size was a significant predictor of carpal tunnel syndrome.     

Duration of ovarian hormone exposure and gynecological cancer risk in Korean women: the Korean Heart Study

BackgroundAlthough reproductive and hormonal factors – such as early menarche and late menopause – have been reported as independent risk factors for cancer, few studies have examined these factors in East Asian populations.MethodsWe performed a large prospective cohort study of 66,466 women. Ovarian hormone exposure was defined as length of time between menarche and menopause. Incidence rates for breast, ovarian, endometrial and cervical cancers were examined separately in relation to reproductive lifespan defined as age at menopause minus age at menarche. Multivariable adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated using the Cox proportional hazards model.ResultsWomen with early menarche were at increased risk for developing breast cancer (HR, 1.57, 95% CI, 1.17–2.10) for age at menarche ≤12 years compared to women with age at menarche ≥17 years. Women with late age at menopause (≥52 years) had increased risks for cancers of the breast (HR, 1.59, 95%CI, 1.11–2.28) and ovary (HR, 3.22, 95% CI, 1.09–9.55) compared to women with early menopause (≤45 years of age). Women with longer duration of ovarian hormone exposure (≥40 years) were at increased risk for developing breast cancer (HR, 2.23, 95% CI, 1.35–3.68) as well as endometrial cancer (p for trend, 0.0209).ConclusionsWe showed that longer reproductive spans are associated with an increased risk of breast and endometrial cancer in Korean women.     

Is breast feeding possible after reduction mammaplasty?

The purpose of this study was (1) to evaluate the frequency of breast feeding in patients who had given birth following reduction mammaplasty using an inferiorly based pedicle flap and (2) to identify operative and nonoperative factors that may affect breast feeding following reduction mammaplasty. Seventy-three patients between the ages of 18 and 40 years were contacted and sent a standardized questionnaire. Data collected included age at pregnancy, duration of breast feeding, difficulties while breast feeding, and reasons for discontinuing breast feeding. A total of 20 patients of the 68 who responded had become pregnant following reduction mammaplasty. All 20 women lactated. Seven of these women (35 percent) went on to a breast-feed successfully, whereas 13 (65 percent) decided not to breast-feed or discontinued breast feeding for a variety of personal reasons.     

Risk factors for breast cancer in women biopsied for benign breast disease: A nested case-control study

Aim: Women with a history of benign breast disease are at increased risk of subsequent breast cancer. However, few studies have examined whether established breast cancer risk factors other than histology are associated with an altered risk of breast cancer in women with benign breast disease. We used a nested case-control design within a large, multi-center cohort of women biopsied for benign breast disease (BBD) to estimate odds ratios for breast cancer in association with exposure to a range of personal and lifestyle factors. Methods: Cases were women biopsied for BBD who subsequently developed breast cancer; controls were individually matched to cases on center and age at diagnosis and were women biopsied for BBD who did not develop breast cancer in the same follow-up interval as that for the cases. After excluding women with prevalent breast cancer, 1357 records (661 case records and 696 records) were available for analysis. We used conditional logistic regression to obtain crude and multivariable-adjusted estimates of the association between specific factors and risk of breast cancer. Results: In multivariable analyses age at first live birth, number of pregnancies, and postmenopausal status were inversely associated with risk of breast cancer. The odds ratio for women with age at first birth <25 years and ≥3 pregnancies, relative to nulliparous women, was 0.49, 95% confidence interval 0.13–0.79, and that for postmenopausal women relative to premenopausal women was 0.60, 95% CI 0.37–0.99. Conclusions: Further study of personal factors influencing the risk of breast cancer in women with BBD may help to identify subgroups of the population at increased risk of invasive disease.     

Lithuanian cohort of Chernobyl cleanup workers: Cancer incidence follow-up 1986–2012

BackgroundCancer risks following radiation exposure in adulthood after Chernobyl are less studied compared to those after exposure in childhood. We aimed to evaluate cancer risk in the Lithuanian cohort of Chernobyl cleanup workers 26 years after their exposure in Chernobyl.MethodsStudy population (6707 men) was followed for cancer incidence upon return from Chernobyl till the end of 2012 by linkage procedure with the Lithuanian Cancer Registry and for migration and death – with Central Population Registry. The site-specific cancer risk in the cohort was estimated by calculating the standardised incidence ratio (SIR) with 95 % confidence interval (CI).ResultsA total of 596 cancer cases was observed in the cohort, against 584 expected (SIR 1.02; 95 % CI 0.94, 1.11). Only incidence of mouth and pharynx cancers was increased compared to the expected (SIR 1.41; 95 % CI 1.07, 1.86). Nevertheless, an increased risk of thyroid cancer was observed among cleanup workers who were younger than 30 years when entering the Chernobyl zone (SIR 2.90; 95 % CI 1.09, 7.72), whose radiation dose was above 100 milisievert (mSv) (SIR 3.13; 95 % CI 1.30, 7.52) and who had shorter duration of stay (SIR 2.30; 95 % CI 1.03, 5.13).ConclusionsOur findings are consistent with those observed in other cohorts of workers, namely, the increased risk of cancer sites related to behavioural factors. The increased risk of thyroid cancer among cleanup workers who were younger than 30 years when entering Chernobyl and whose radiation dose was above 100 mSv cannot exclude the association with the radiation exposure in Chernobyl.     

Magnetic fields of high voltage power lines and risk of cancer in Finnish adults: nationwide cohort study.

OBJECTIVE: To investigate the risk of cancer in association with magnetic fields in Finnish adults living close to high voltage power lines. DESIGN: Nationwide cohort study. SUBJECTS: 383,700 people who lived during 1970-89 within 500 metres of overhead power lines of 110-400 kV in a magnetic field calculated to be > or = 0.01 microT. Study subjects were identified by record linkages of nationwide registers. MAIN OUTCOME MEASURES: Numbers of observed and expected cases of cancer, standardised incidence ratios, and incidence rate ratios adjusted for sex, age, calendar year, and social class--for example, by continuous cumulative exposure per 1 microT year with 95% confidence intervals from multiplicative models for all cancers combined and 21 selected types. RESULTS: Altogether 8415 cases of cancer were observed (standardised incidence ratio 0.98; 95% confidence interval 0.96 to 1.00) in adults. All incidence rate ratios for both sexes combined were non-significant and between 0.91 and 1.11. Significant excesses were observed in multiple myeloma in men (incidence rate ratio 1.22) and in colon cancer in women (1.16). CONCLUSIONS: Typical residential magnetic fields generated by high voltage power lines do not seem to be related to the risk of overall cancer in adults. The previously suggested associations between extremely low frequency magnetic fields and tumours of the nervous system, lymphoma, and leukaemia in adults and breast cancer in women were not confirmed.     

Conservation therapy for breast cancer following augmentation mammaplasty

Breast conservation therapy (wide local excision, axillary lymph node dissection, and whole-breast irradiation) is an increasingly popular alternative to mastectomy for breast cancer patients. A sizable (and growing) number of breast cancers occur in women with prior augmentation mammaplasty. Augmented breast cancer patients are currently being treated with conservation therapy, but no study has investigated complications and cosmetic results of radiation therapy specifically in this group of women. Between 1981 and 1988, we used conservation therapy in 17 augmented breast cancer patients. Fifteen patients were available for follow-up. In 10 (67 percent), significant capsular contracture occurred in the irradiated breast an average of 12 weeks following completion of treatment. Four patients have undergone revisionary surgery to correct symptoms arising from contracture. This poor outcome contradicts the results reported in previously published studies. We conclude that irradiation of the breast for cancer in augmented women results in a high incidence of scar-tissue contracture and poor cosmetic results.     

Marked increase in breast cancer incidence in young women: A 10-year study from Northern Iran, 2004–2013

IntroductionBreast cancer is the most frequent cancer among women worldwide. Breast cancer incidence in young women is a health issue of concern, especially in middle-income countries such as Iran. The aim of this study is to report the breast cancer incidence variations in Golestan province, Iran, over a 10-year period (2004–2013).MethodsWe analyzed data from the Golestan Population-based Cancer Registry (GPCR), which is a high-quality cancer registry collecting data on primary cancers based on standard protocols throughout the Golestan province. Age-standardized incidence rates (ASRs) and age-specific incidence rates per 100,000 person-years were calculated. Time trends in ASRs and age-specific rates were evaluated using Joinpoint regressions. The average annual percentage change (AAPC) with correspondence 95% confidence intervals (95%CIs) were calculated.ResultsA total of 2106 new breast cancer cases were diagnosed during the study period. Most cases occurred in women living in urban areas: 1449 cases (68%) versus 657 cases (31%) in rural areas. Statistically significant increasing trends were observed over the 10-year study period amongst women of all ages (AAPC = 4.4; 95%CI: 1.2–7.8) as well as amongst women in the age groups 20–29 years (AAPC = 10.0; 95%CI: 1.7–19.0) and 30–39 years (AAPC = 5.1; 95%CI: 1.4–9.0).ConclusionThe incidence of breast cancer increased between 2004 and 2013 in Golestan province amongst all age groups, and in particular amongst women aged 20–39 years. Breast cancer should be considered a high priority for health policy making in our community.     

Energy-Related Indicators and Breast Cancer Risk among White and Black Women

Energy-related indicators, including physical activity, energy intake, body mass index (BMI) and adult weight change, have been linked to breast cancer risk. Very few studies of these associations have been conducted among black women, therefore we used the Nashville Breast Health Study (NBHS) to determine whether similar effects were seen in black and white women. The NBHS is a population-based case-control study of breast cancer among women age 25 to 75 years conducted between 2001 and 2010 in and around the Nashville Metropolitan area. Telephone interviews and self-administered food frequency questionnaires were completed with 2,614 incident breast cancer cases ascertained through hospitals and the statewide cancer registry, and 2,306 controls selected using random digit dialing. Among premenopausal white and black women, there was little effect of adult exercise or other energy-related indicators on breast cancer risk, regardless of tumor estrogen receptor (ER) status. The beneficial effect of adult exercise on postmenopausal breast cancer appeared to be comparable between white and black women (highest tertile relative to none - white odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-1.0, p for trend=0.05; black OR 0.7, 95% CI 0.4-1.1, p for trend=0.07); however, among black women the reduction was limited to those with ER-positive disease. White and black women should be encouraged to engage in more physical activity to reduce their risk of postmenopausal breast cancer.     

Incidence of Cancer in ANCA-Associated Vasculitis: A Meta-Analysis of Observational Studies

ObjectiveThe purpose of this paper is to examine cancer incidence in patients with ANCA-associated vasculitis (AASV) derived from population-based cohort studies by means of meta-analysis.MethodsRelevant electronic databases were searched for studies characterizing the associated risk of overall malignancy in patients with AASV. Standardized incidence rates (SIRs) with 95% confidence intervals (CIs) were used to evaluate the strength of association. We tested for publication bias and heterogeneity and stratified for site-specific cancers.ResultsSix studies (n = 2,578) were eventually identified, of which six provided the SIR for overall malignancy, five reported the SIR for non-melanoma skin cancer (NMSC), four for leukemia, five for bladder cancer, three for lymphoma, three for liver cancer, four for lung cancer, three for kidney cancer, four for prostate cancer, four for colon cancer and four for breast cancer. Overall, the pooled SIR of cancer in AASV patients was 1.74 (95%CI = 1.37–2.21), with moderate heterogeneity among these studies (I² = 65.8%, P = 0.012). In sub-analyses for site-specific cancers, NMSC, leukemia and bladder cancer were more frequently observed in patients with AASV with SIR of 5.18 (95%CI = 3.47–7.73), 4.89 (95%CI = 2.93–8.16) and 3.84 (95%CI = 2.72–5.42) respectively. There was no significant increase in the risk of kidney cancer (SIR = 2.12, 95%CI = 0.66–6.85), prostate cancer (SIR = 1.45, 95%CI = 0.87–2.42), colon cancer (SIR = 1.26, 95%CI = 0.70–2.27), and breast cancer (SIR = 0.95, 95%CI = 0.50–1.79). Among these site-specific cancers, only NMSC showed moderate heterogeneity (I² = 55.8%, P = 0.06). No publication bias was found by using the Begg’s test and Egger''s test.ConclusionsThis meta-analysis shows that AASV patients treatment with cyclophosphamide (CYC) are at increased risk of late-occurring malignancies, particularly of the NMSC, leukemia and bladder cancer. However, there is no significant association between AASV and kidney cancer, prostate cancer, colon cancer and breast cancer. These findings emphasize monitoring and preventative management in AASV patients after cessation of CYC therapy is momentous.     

A follow-up study of 105 women with breast cancer following reduction mammaplasty.

Reduction mammaplasty is one of the most common procedures performed by plastic surgeons in Canada. In a recent study of 27,500 women in the province of Ontario who underwent breast reduction surgery, 105 women were identified who developed breast cancer after reduction mammaplasty. The purpose of this study was to compare women who had breast cancer and had a previous breast reduction with women who had breast cancer but did not have a breast reduction. Specifically, we wanted to document patient demographics, cancer type, surgical and nonsurgical treatment, and eventual outcome. A comparison group of non-breast reduction women was taken from the cohort of breast cancer patients in the province of Ontario, and the two groups were matched for age, year of diagnosis, and place of diagnosis. It was found that (1) the average age at diagnosis of breast cancer is significantly younger for women who have had previous breast reduction surgery than for those who have not; (2) the median interval between breast reduction and cancer is 5 years; (3) the type, location, and side of breast cancers are similar in the two groups of women; (4) breast reduction does not significantly increase or decrease survival rate from breast cancer; and (5) women who have had breast reduction receive the same treatment for their breast cancer as women who have not had reduction mammaplasty.     

Breast cancer incidence by country of birth among immigrant women in British Columbia,Canada

IntroductionBreast cancer rates vary internationally and between immigrant and non-immigrant populations. We describe breast cancer incidence by birth region and country in British Columbia, Canada.MethodsWe linked population-based health and immigration databases for a population with >1.29 million immigrants to assess breast cancer incidence among immigrant and non-immigrant women. We report age-standardized incidence ratios (SIRs) by birth region and country using non-immigrant women as the standard.ResultsSIRs varied widely by both birth country and region. Low rates were found for South (SIR = 0.52, 95% CI: 0.47,0.59) and East Asian (SIR = 0.75, 95% CI: 0.72,0.79) women and a higher rate for Western Europeans (SIR = 1.15, 95% CI: 1.01,1.30).ConclusionThere is considerable variation in SIRs across some of British Columbia’s largest immigrant populations and several demonstrate significantly different risk profiles compared to non-immigrants. These findings provide unique data to support breast cancer prevention and control.