Causes of death in men with prostate cancer: Results from the Danish Prostate Cancer Registry (DAPROCAdata)

BackgroundCurrent knowledge of the validity of registry data on prostate cancer-specific death is limited. We aimed to determine the underlying cause of death among Danish men with prostate cancer, to estimate the level of misattribution of prostate cancer death, and to examine the risk of death from prostate cancer when accounting for competing risk of death.Material and methodsWe investigated a nationwide cohort of 15,878 prostate cancer patients diagnosed in 2010–2014; with 3343 deaths occurring through 2016. Blinded medical chart review was carried out for 670 deaths and compared to the national cause of death registry. Five death categories were defined: 1) prostate cancer-specific death, 2) other unspecified urological cancer death, 3) other cancer death 4) cardiovascular disease death, and 5) other causes of death. Competing risk analyses compared Cox cause-specific and Fine-Gray regression models.ResultsChart review attributed 51.2% of deaths to prostate cancer, 17.0% to cardiovascular disease, and 16.7% to other causes. The Danish Register of Causes of Death attributed 71.7% of deaths to prostate cancer when including all registered contributing causes of death, and 57.0% of deaths when including only the primary registered cause of death. The probability of death by prostate cancer was 10% at 2-year survival.ConclusionsMore than half of the deceased men in our study cohort died of their prostate cancer disease within a mean of 2.4 years of follow up. Data from the death registry is prone to misclassification, potentially overestimating the proportion of deaths from prostate cancer.     

Temporal trends in net and crude probability of death from cancer and other causes in the Australian population, 1984–2013

BackgroundWhile net probabilities of death in the relative survival framework ignore competing causes of death, crude probabilities allow estimation of the real risk of cancer deaths. This study quantifies temporal trends in net and crude probabilities of death.MethodsAustralian population-based cohort of 2,015,903 people aged 15-89 years, diagnosed with a single primary invasive cancer from 1984 to 2013 with mortality follow-up to 31 December 2014. Survival was analyzed with the cohort method. Flexible parametric relative survival models were used to estimate both probability measures by diagnosis year for all cancers and selected leading sites.ResultsFor each site, excess mortality rates reduced over time, especially for prostate cancer. While both the 10-year net and crude probability of cancer deaths decreased over time, specific patterns varied. For example, the crude probability of lung cancer deaths for males aged 50 years decreased from 0.90 (1984) to 0.79 (2013); whereas the corresponding probabilities for kidney cancer were 0.64 and 0.18 respectively. Patterns for crude probabilities of competing deaths were relatively constant. Although for younger patients, both net and crude measures were similar, crude probability of competing deaths increased with age, hence for older ages net and crude measures were different except for lung and pancreas cancers.ConclusionsThe observed reductions in probabilities of death over three decades for Australian cancer patients are encouraging. However, this study also highlights the ongoing mortality burden following a cancer diagnosis, and the need for continuing efforts to improve cancer prevention, diagnosis and treatment.     

Surgical resection as a predictor of cancer-specific survival by stage at diagnosis and cancer type,United States, 2006–2015

BackgroundWhen solid tumors are amenable to definitive resection, clinical outcomes are generally superior to when those tumors are inoperable. However, the population-level cancer survival benefit of eligibility for surgery by cancer stage has not yet been quantified.MethodsUsing Surveillance, Epidemiology and End Results data allowing us to identify patients who were deemed eligible for and received surgical resection, we examined the stage-specific association of surgical resection with 12-year cancer-specific survival. The 12-year endpoint was selected to maximize follow-up time and thereby minimize the influence of lead time bias.ResultsAcross a variety of solid tumor types, earlier stage at diagnosis allowed for surgical intervention at a much higher rate than later-stage diagnosis. At every stage, surgical intervention was associated with a substantially higher rate of 12-year cancer-specific survival, with absolute differences of up to 51% for stage I, 51% for stage II, and 44% for stage III cancer, and stage-specific mortality relative risks of 3.6, 2.4, and 1.7, respectively.ConclusionsDiagnosis of solid cancers in early stages often enables surgical resection, which reduces the risk of death from cancer. Receipt of surgical resection is an informative endpoint that is strongly associated with long-term cancer-specific survival at every stage.     

Quantifying Cancer Absolute Risk and Cancer Mortality in the Presence of Competing Events after a Myotonic Dystrophy Diagnosis

Recent studies show that patients with myotonic dystrophy (DM) have an increased risk of specific malignancies, but estimates of absolute cancer risk accounting for competing events are lacking. Using the Swedish Patient Registry, we identified 1,081 patients with an inpatient and/or outpatient diagnosis of DM between 1987 and 2007. Date and cause of death and date of cancer diagnosis were extracted from the Swedish Cause of Death and Cancer Registries. We calculated non-parametric estimates of absolute cancer risk and cancer mortality accounting for the high non-cancer competing mortality associated with DM. Absolute cancer risk after DM diagnosis was 1.6% (95% CI=0.4-4%), 5% (95% CI=3-9%) and 9% (95% CI=6-13%) at ages 40, 50 and 60 years, respectively. Females had a higher absolute risk of all cancers combined than males: 9% (95% CI=4-14), and 13% (95% CI=9-20) vs. 2% (95%CI= 0.7-6) and 4% (95%CI=2-8) by ages 50 and 60 years, respectively) and developed cancer at younger ages (median age =51 years, range=22-74 vs. 57, range=43-84, respectively, p=0.02). Cancer deaths accounted for 10% of all deaths, with an absolute cancer mortality risk of 2% (95%CI=1-4.5%), 4% (95%CI=2-6%), and 6% (95%CI=4-9%) by ages 50, 60, and 70 years, respectively. No gender difference in cancer-specific mortality was observed (p=0.6). In conclusion, cancer significantly contributes to morbidity and mortality in DM patients, even after accounting for high competing DM mortality from non-neoplastic causes. It is important to apply population-appropriate, validated cancer screening strategies in DM patients.     

Survival Analysis of Patients with Interval Cancer Undergoing Gastric Cancer Screening by Endoscopy

AimsInterval cancer is a key factor that influences the effectiveness of a cancer screening program. To evaluate the impact of interval cancer on the effectiveness of endoscopic screening, the survival rates of patients with interval cancer were analyzed.MethodsWe performed gastric cancer-specific and all-causes survival analyses of patients with screen-detected cancer and patients with interval cancer in the endoscopic screening group and radiographic screening group using the Kaplan-Meier method. Since the screening interval was 1 year, interval cancer was defined as gastric cancer detected within 1 year after a negative result. A Cox proportional hazards model was used to investigate the risk factors associated with gastric cancer-specific and all-causes death.ResultsA total of 1,493 gastric cancer patients (endoscopic screening group: n = 347; radiographic screening group: n = 166; outpatient group: n = 980) were identified from the Tottori Cancer Registry from 2001 to 2008. The gastric cancer-specific survival rates were higher in the endoscopic screening group than in the radiographic screening group and the outpatients group. In the endoscopic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer and the patients with interval cancer were nearly equal (P = 0.869). In the radiographic screening group, the gastric cancer-specific survival rate of the patients with screen-detected cancer was higher than that of the patients with interval cancer (P = 0.009). For gastric cancer-specific death, the hazard ratio of interval cancer in the endoscopic screening group was 0.216 for gastric cancer death (95%CI: 0.054-0.868) compared with the outpatient group.ConclusionThe survival rate and the risk of gastric cancer death among the patients with screen-detected cancer and patients with interval cancer were not significantly different in the annual endoscopic screening. These results suggest the potential of endoscopic screening in reducing mortality from gastric cancer.     

Association between disparities in intergenerational economic mobility and cause-specific mortality among Black and White persons in the United States

BackgroundEvidence about the association between structural racism and mortality in the United States is limited. We examined the association between ongoing structural racism, measured as inequalities in adulthood income between White and Black children with similar parental household income (economic mobility gap) in a recent birth cohort, and Black-White disparities in death rates (mortality gap) overall and for major causes.MethodsSex-, race/ethnicity-, and county-specific data were used to examine sex-specific associations between economic mobility and mortality gaps for all causes combined, heart diseases, cerebrovascular diseases, chronic obstructive pulmonary disease (COPD), injury/violence, all malignant cancers, and 14 cancer types. Economic mobility data for 1978–1983 birth cohorts and death rates during 2011–2018 were obtained from the Opportunity Atlas and National Center for Health Statistics, respectively. Data from 471 counties were included in analyses of all-cause mortality at ages 30−39 years during 2011–2018 (corresponding to partially overlapping 1978–1983 birth cohorts); and from 1,572 and 1,248 counties in analyses of all-cause and cause-specific mortality in all ages combined, respectively.ResultsIn ages 30−39 years, a one percentile increase in the economic mobility gap was associated with a 6.8 % (95 % confidence interval 1.8 %–11.8 %) increase in the Black-White mortality gap among males and a 13.5 % (8.9 %–18.1 %) increase among females, based on data from 471 counties. In all ages combined, the corresponding percentages based on data from 1,572 counties were 10.2 % (7.2 %–13.2 %) among males and 14.8 % (11.4 %–18.2 %) among females, equivalent to an increase of 18.4 and 14.0 deaths per 100,000 in the mortality gap, respectively. Similarly, strong associations between economic mobility gap and mortality gap in all ages were found for major causes of death, notably for potentially preventable conditions, including COPD, injury/violence, and cancers of the lung, liver, and cervix.ConclusionsEconomic mobility gap conditional on parental income in a recent birth cohort as a marker of ongoing structural racism is strongly associated with Black-White disparities in all-cause mortality and mortality from several causes.     

Epidemiological trends of neuroendocrine tumours over three decades in Queensland,Australia

IntroductionWhile neuroendocrine tumours (NETs) account for only a small proportion of cancer diagnoses, incidence has been rising over time. We examined incidence, mortality and survival over three decades in a large population-based registry study.MethodsThis retrospective study included all cases (n = 4580) of NETs diagnosed from 1986 to 2015 in Queensland, Australia. We examined directly age-standardised incidence and mortality rates. The impact on overall survival according to demographic factors and primary site was modelled using multivariable Cox proportional hazards regression (HR). Cause-specific and relative survival were estimated using the Kaplan-Meier survival function.ResultsAnnual incidence increased from 2.0 in 1986 to 6.3 per 100,000 in 2015, while mortality remained stable. The most common primary site was appendix followed by lung, small intestine and rectum. Rectal, stomach, appendiceal and pancreatic NETs had the greatest rate increase, while lung NETs decreased over the same period. Five-year cause-specific survival improved from 69.4% during 1986–1995 to 92.6% from 2006 to 2015. Survival was highest for appendiceal and rectal NETs and lowest for pancreas and unknown primary sites. The risk of dying within five years of diagnosis was about 40% higher for males (HR = 1.41, 95%CI 1.20–1.65) and significantly higher for patients aged over 40 years compared to younger patients (p < 0.001).ConclusionThis study, including 30 years of data, found significantly increasing rates of NETs and confirms results from elsewhere. Increasing survival over time in this study, likely reflects increased awareness, improvements in diagnostic imaging, greater use of endoscopy and colonoscopy, and the development of new therapies.     

Gastric cancer epidemiology from 2009 to 2019 in Dnipro Region,Ukraine

BackgroundGastric cancer (GC) is in top-five the most frequent cancers in Ukrainian males and is the third cause of death among patients with cancer. GC keeps its leading position in cancer ranks despite the decline in incidence and mortality over the last 50 years. Local epidemiological information will help in better targeting medical and public health interventions.Patients and methodsThe data about 8438 patients with newly diagnosed GC between 2009 and 2019 was obtained from Dnipro Cancer Registry.ResultsIncidence decreased from 24.5 to 22.6, mortality decreased from 21.4 to 15.7 (per 100000), death rate increased from 0.64 to 1.04 between 2009 and 2019. Over 11 years of observation incidence was 23.4, mortality was 19.4, death rate was 0.721. Standardised incidence ratio was 1.42, standardised mortality rate was 1.67; age-standardised incidence was 25.5, age-standardised mortality was 21.2 (European standard). Median (95% confidence interval (95% CI)) survival of the patients was 172 (165−178) days. One-year survival rate fluctuated between 27% and 34%. Male sex and older age were associated with higher risk of death (hazard ratio (95% CI) – 1.08 (1.03–1.13) vs females and 1.15 (1.12–1.17) per 10-years increase of age, respectively).ConclusionsThe study describes the trends in epidemiology of gastric cancer in Dnipro region, Ukraine, between 2009 and 2019. The need for the national prevention strategy of GC in Ukraine was identified.     

Lifetime Smoking History and Cause-Specific Mortality in a Cohort Study with 43 Years of Follow-Up

BackgroundIn general, smoking increases the risk of mortality. However, it is less clear how the relative risk varies by cause of death. The exact impact of changes in smoking habits throughout life on different mortality risks is less studied.MethodsWe studied the impact of baseline and lifetime smoking habits, and duration of smoking on the risk of all-cause mortality, mortality of cardiovascular diseases (CVD), chronic obstructive pulmonary disease (COPD), any cancer and of the four most common types of cancer (lung, colorectal, prostate, and breast cancer) in a cohort study (Vlagtwedde-Vlaardingen 1965–1990, with a follow-up on mortality status until 2009, n = 8,645). We used Cox regression models adjusted for age, BMI, sex, and place of residence. Since previous studies suggested a potential effect modification of sex, we additionally stratified by sex and tested for interactions. In addition, to determine which cause of death carried the highest risk we performed competing-risk analyses on mortality due to CVD, cancer, COPD and other causes.ResultsCurrent smoking (light, moderate, and heavy cigarette smoking) and lifetime persistent smoking were associated with an increased risk of all-cause, CVD, COPD, any cancer, and lung cancer mortality. Higher numbers of pack years at baseline were associated with an increased risk of all-cause, CVD, COPD, any cancer, lung, colorectal, and prostate cancer mortality. Males who were lifetime persistent pipe/cigar smokers had a higher risk of lung cancer [HR (95% CI) = 7.72 (1.72–34.75)] as well as all-cause and any cancer mortality. A longer duration of smoking was associated with a higher risk of COPD, any and lung cancer [HR (95% CI) = 1.06 (1.00–1.12), 1.03 (1.00–1.06) and 1.10 (1.03–1.17) respectively], but not with other mortality causes. The competing risk analyses showed that ex- and current smokers had a higher risk of cancer, CVD, and COPD mortality compared to all other mortality causes. In addition, heavy smokers had a higher risk for COPD mortality compared to cancer, and CVD mortality.ConclusionOur study indicates that lifetime numbers of cigarettes smoked and the duration of smoking have different impacts for different causes of mortality. Moreover, our findings emphasize the importance of smoking-related competing risks when studying the smoking-related cancer mortality in a general population and that smoking cessation immediately effectively reduces the risk of all-cause and any cancer mortality.     

Improving the reporting of cancer-specific mortality and survival in research using cancer registry data

Population-based registries are increasingly used in cancer research. In such studies, cancer-specific mortality or survival is frequently used as the primary outcome. To determine whether a putative cancer was part of the causal chain of events leading to death, cancer registries primarily rely on death certificates. Hence, they depend on the subjective interpretation of information available to medical examiners at the time of death. Misclassification may occur: studies report misclassification of cancer as a cause of death in 15%–35% of death certificates based on evaluation by expert panels and/or autopsy reports. Further misclassification may occur when coding death causes in the cancer registry. Researchers should be aware of potential misclassification bias when using cancer registry data. Differential misclassification may bias the results towards or away from the null hypothesis, depending on whether there is relative over- or under-reporting of cancer-related deaths in one group. Strategies to improve reporting of cancer-specific survival/mortality include (1) describing the procedure used to identify cancer-specific deaths; (2) considering the use of multiple definitions of cancer-related deaths (strict/liberal definitions of cancer-specific deaths, and/or addition of relative survival as an outcome); and (3) reporting cancer-specific survival/mortality together with the objectively measured parameters overall survival or all-cause mortality.     

The outcome of patients with serous papillary peritoneal cancer,fallopian tube cancer,and epithelial ovarian cancer by treatment eras: 27 years data from the SEER registry

AimTo determine the differential effect of the treatment periods on the survival of patients with stage IV serous papillary peritoneal carcinoma (SPPC), fallopian tube cancers, and epithelial ovarian cancers (EOC).MethodsThis was an exploratory, population-based observational study of all patients with stage IV SPPC, fallopian tube cancers, and EOC collected from the SEER Research Data 1973–2017. The study period was divided into three time-periods: platinum combinations before the taxane era (1990–1995), platinum plus taxane chemotherapy era (1996–2013), and bevacizumab era (2014–2017).ResultsA total of 9828 patients were eligible for analyses: SPPC (3898 patients; 39.7%), fallopian tube cancers (1290 patients; 13.1%) and EOC (4640 patients, 47.2%). In the 1990–1995 era, the 3-year cause-specific survival was 40% for SPPC, 53% for fallopian tube cancers, and 40% for POC. In the following era 1993–2013, the 3-year cause-specific survival increased to 55% for SPPC, 74% for fallopian tube cancers, and 45% for POC. The last era 2014–2017 showed a 3-year cause-specific survival of 64%, 67%, and 45% for patients with SPPC, fallopian tube cancers, and POC, respectively. The differences in cause-specific survival were statistically significant for patients with SPPC (p=0.004). Multivariable analysis showed that the treatment eras and age at diagnosis were associated with cause-specific survival.ConclusionThe results of this study are hypothesis-generating and cannot be considered conclusive given the inherent limitations of registry analysis. Subgroup analyses of the phase III randomized controlled trials, by tumor subset (EOC, fallopian tube cancer, and SPPC) would shed more light on the differential effects of novel therapies.     

The impact of under and over-recording of cancer on death certificates in a competing risks analysis: A simulation study

Background: With linked register and cause of death data becoming more accessible than ever, competing risks methodology is being increasingly used as a way of obtaining “real world” probabilities of death broken down by specific causes. It is important, in terms of the validity of these studies, to have accurate cause of death information. However, it is well documented that cause of death information taken from death certificates is often lacking in accuracy and completeness. Methods: We assess through use of a simulation study the effect of under and over-recording of cancer on death certificates in a competing risks analysis consisting of three competing causes of death: cancer, heart disease and other causes. Using realistic levels of misclassification, we consider 24 scenarios and examine the bias in the cause-specific hazard ratios and the cumulative incidence function. Results: The bias in the cumulative incidence function was highest in the oldest age group reaching values as high as 2.6 percentage units for the “good” cancer prognosis scenario and 9.7 percentage units for the “poor” prognosis scenario. Conclusion: The bias resulting from the chosen levels of misclassification in this study accentuate concerns that unreliable cause of death information may be providing misleading results. The results of this simulation study convey an important message to applied epidemiological researchers.     

Disparities in survival improvement for U.S. childhood and adolescent cancer between 1995 and 2019: An analysis of population-based data

BackgroundAlthough treatment advances have increased childhood and adolescent cancer survival, whether patient subgroups have benefited equally from these improvements is unclear.MethodsData on 42,865 malignant primary cancers diagnosed between 1995 and 2019 in individuals ≤ 19 years were obtained from 12 Surveillance, Epidemiology, and End Results registries. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer-specific mortality by age group (0–14 and 15–19 years), sex, and race/ethnicity were estimated using flexible parametric models with a restricted cubic spline function in each of the periods: 2000–2004, 2005–2009, 2010–2014 and 2015–2019, versus 1995–1999. Interactions between diagnosis period and age group (children 0–14 and adolescents 15–19 years at diagnosis), sex, and race/ethnicity were assessed using likelihood ratio tests. Five-year cancer-specific survival rates for each diagnosis period were further predicted.ResultsCompared with the 1995–1999 cohort, the risk of dying from all cancers combined decreased in subgroups defined by age, sex and race/ethnicity with HRs ranging from 0.50 to 0.68 for the 2015–2019 comparison. HRs were more variable by cancer subtype. There were no statistically significant interactions by age group (P_interaction=0.05) or sex (P_interaction=0.71). Despite non-significant differences in cancer-specific survival improvement across different races and ethnicities (P_interaction=0.33) over the study period, minorities consistently experienced inferior survival compared with non-Hispanic Whites.ConclusionsThe substantial improvements in cancer-specific survival for childhood and adolescent cancer did not differ significantly by different age, sex, and race/ethnicity groups. However, persistent gaps in survival between minorities and non-Hispanic Whites are noteworthy.     

Twenty years of melanoma in Victoria,Queensland, and South Australia (1997 – 2016)

BackgroundGiven the high incidence of melanoma in Australia alongside high mortality with later stage disease, we investigated the populations and locations most at risk, to optimise public health activities in areas where intervention is most needed. This study examines trends and identifies significant prognostic factors and potential disparities in incidence, mortality and survival between population groups in Victoria, Queensland and South Australia.MethodsThe analysis includes data from the population-based cancer registries of the three states over a twenty-year period (1997–2016). Age-standardized and age-specific incidence rates were calculated, and long-term trends analysed using Joinpoint Regression. Five-year relative survival estimates for the study population were calculated using the cohort method and multivariable flexible parametric survival models were applied for each jurisdiction to calculate adjusted excess mortality hazard ratios for the key characteristics.ResultsThere were more males with melanoma than females in all the three states. Over 60% of the cases occurred in the 40–74 years age group. Most melanomas had a Breslow thickness less than or equal to 1.0 mm. For males, Victoria and Queensland had a statistically significant increasing trend whereas in South Australia there was a decreasing trend. For females, the incidence rate trend was stable in Victoria but significantly decreasing in South Australia. In Queensland there was an increasing and statistically significant trend from 2006 to 2016. Across all three states there was a reducing incidence rate in the youngest cohort, stabilizing incidence in the 40–59-year-old age group, and increasing in the oldest cohorts. Five-year relative survival decreased with increasing age and with Breslow thickness across all three jurisdictions. Males had between 43%− 46% excess mortality compared to females in all the three states. There was higher risk with increasing age and Breslow thickness, with the largest risk among the 75 + age group and those with a Breslow thickness of > 4 mm.ConclusionIt is the first time that data from these three registries has been analysed together in a uniform way, covering more than half of the Australian population. This study compares the epidemiology of melanoma across three states and provides a better understanding of trends and factors affecting outcome for Australians with melanoma. While there has been some improvement in aspects of incidence and mortality, this has not been evenly achieved across Australia.     

Relative rates of cancers and deaths in Australian communities with PFAS environmental contamination associated with firefighting foams: A cohort study using linked data

BackgroundPer- and polyfluoroalkyl substances (PFAS) are environmental contaminants that are potentially harmful to health. We examined if rates of selected cancers and causes of deaths were elevated in three Australian communities with local environmental contamination caused by firefighting foams containing PFAS. The affected Australian communities were Katherine in Northern Territory, Oakey in Queensland and Williamtown in New South Wales.MethodsAll residents identified in the Medicare Enrolment File (1983–2019)—a consumer directory for Australia’s universal healthcare—who ever lived in an exposure area (Katherine, Oakey and Williamtown), and a sample of those who ever lived in selected comparison areas, were linked to the Australian Cancer Database (1982–2017) and National Death Index (1980–2019). We estimated standardised incidence ratios (SIRs) for 23 cancer outcomes, four causes of death and three control outcomes, adjusting for sex, age and calendar time of diagnosis.FindingsWe observed higher rates of prostate cancer (SIR=1·76, 95 % confidence interval (CI) 1·36–2·24) in Katherine; laryngeal cancer (SIR=2·71, 95 % CI 1·30–4·98), kidney cancer (SIR=1·82, 95 % CI 1·04–2·96) and coronary heart disease (CHD) mortality (SIR=1·81, 95 % CI 1·46–2·33) in Oakey; and lung cancer (SIR=1·83, 95 % CI 1·39–2·38) and CHD mortality (SIR=1·22, 95 % CI 1·01–1·47) in Williamtown. We also saw elevated SIRs for control outcomes. SIRs for all other outcomes and overall cancer were similar across exposure and comparison areas.InterpretationThere was limited evidence to support an association between living in a PFAS exposure area and risks of cancers or cause-specific deaths.     

Effect of radiation exposure on survival after first solid cancer diagnosis in A-bomb survivors

BackgroundComparison of the estimated effect of atomic bomb radiation exposure on solid cancer incidence and solid cancer mortality in the RERF Life Span Study (LSS) reveals a difference in the magnitude and shape of the excess relative risk dose response. A possible contributing factor to this difference is pre-diagnosis radiation effect on post-diagnosis survival. Pre-diagnosis radiation exposure theoretically could influence post-diagnosis survival by affecting the genetic makeup and possibly aggressiveness of cancer, or by compromising tolerance for aggressive treatment for cancer.MethodsWe analyze the radiation effect on post-diagnosis survival in 20,463 LSS subjects diagnosed with first-primary solid cancer between 1958 and 2009 with particular attention to whether death was caused by the first-primary cancer, other cancer, or non-cancer diseases.ResultsFrom multivariable Cox regression analysis of cause-specific survival, the excess hazard at 1 Gy (EH_1Gy) for death from the first primary cancer was not significantly different from zero – p = 0.23, EH_1Gy = 0.038 (95 % CI: −0.023, 0.104). Death from other cancer and death from non-cancer diseases both were significantly associated with radiation dose: other cancer EH_1Gy = 0.38 (95 % CI: 0.24, 0.53); non-cancer EH_1Gy = 0.24 (95 % CI: 0.13, 0.36), both p < 0.001.ConclusionThere is no detectable large effect of pre-diagnosis radiation exposure on post-diagnosis death from the first primary cancer in A-bomb survivors.ImpactA direct effect of pre-diagnosis radiation exposure on cancer prognosis is ruled out as an explanation for the difference in incidence and mortality dose response in A-bomb survivors.     

Cancer mortality 1981–2016 and contribution of specific cancers to current socioeconomic inequalities in all cancer mortality: A population-based study

BackgroundIn many high-income countries cancer mortality rates have declined, however, socioeconomic inequalities in cancer mortality have widened over time with those in the most deprived areas bearing the greatest burden. Less is known about the contribution of specific cancers to inequalities in total cancer mortality.MethodsUsing high-quality routinely collected population and mortality records we examine long-term trends in cancer mortality rates in Scotland by age group, sex, and area deprivation. We use the decomposed slope and relative indices of inequality to identify the specific cancers that contribute most to absolute and relative inequalities, respectively, in total cancer mortality.ResultsCancer mortality rates fell by 24 % for males and 10 % for females over the last 35 years; declining across all age groups except females aged 75+ where rates rose by 14 %. Lung cancer remains the most common cause of cancer death. Mortality rates of lung cancer have more than halved for males since 1981, while rates among females have almost doubled over the same period.ConclusionCurrent relative inequalities in total cancer mortality are dominated by inequalities in lung cancer mortality, but with contributions from other cancer sites including liver, and head and neck (males); and breast (females), stomach and cervical (younger females). An understanding of which cancer sites contribute most to inequalities in total cancer mortality is crucial for improving cancer health and care, and for reducing preventable cancer deaths.     

Occupational disparities in survival from common cancers in Japan: Analysis of Kanagawa cancer registry

BackgroundLittle is known about occupational disparities in survival for common cancer sites in Japan.MethodsUsing data from a population-based cancer registry, we identified 32,870 cancer patients diagnosed during 1992–2011. We followed the patients for 5 years (median follow-up time 5.0 years). For each individual, we classified their longest-held occupation into 5 classes (upper non-manual, lower non-manual, manual, farmer, and others) following the Erikson-Goldthorpe-Portocarero scheme. Poisson regression models were used to estimate overall and site-specific mortality rate ratios (MRRs) and 95% confidence intervals (CI) for each occupational class, adjusted for sex, age, and diagnosis year. Upper non-manual workers served as the reference group. Additionally, using a binary categorization of occupations (manual workers versus non-manual workers), a causal mediation analysis with 4-way decomposition was performed to investigate the potential mediation of the association between occupation and overall mortality by cancer stage.ResultsOverall prognosis was good in this population (5-year overall survival was 81.7%). Compared with upper non-manual workers, both overall and cancer-specific mortality was higher in lower non-manual workers (MRR=1.14, 95% CI 1.05–1.24) and manual workers (MRR=1.40, 95% CI 1.29–1.53). After adjusting for the mediating influence of prognostic factors (stage and treatment), the observed occupational differences were attenuated but remained significant in manual workers: MRR = 1.23 (95% CI 1.08–1.39). Observed occupational disparities tended to be attributable to common cancers, i.e., stomach and lung among men and female breast cancer. Additionally, manual workers had 1.25 times higher odds for advanced stage. In the mediation analysis, the overall proportion explained by mediating effect of cancer stage was 29% (4% due to mediated interaction and 25% due to pure indirect effect).ConclusionWe documented occupational disparities in survival from commonly-occurring cancers in Japan. Occupational differences in cancer stage may explain one-third of the survival disparities.     

The effect of the Flemish breast cancer screening program on breast cancer-specific mortality: A case-referent study

BackgroundBreast cancer screening programs were introduced in many countries worldwide following randomized controlled trials in the 1980s showing a reduction in breast cancer-specific mortality. However, their effectiveness remains debated and estimates vary. A breast cancer screening program was introduced in 2001 in Flanders, Belgium where high levels of opportunistic screening practices are observed. The effectiveness of this program was estimated by measuring its effect on breast cancer-specific mortality.MethodsWe performed a case-referent study to investigate the effect of participation in the Flemish population-based mammography screening program (PMSP) on breast cancer-specific mortality from 2005 to 2017. A multiple logistic regression model assessed the association between breast cancer-specific death and screening program participation status in the four years prior to (pseudo)diagnosis (yes/no), with adjustment for potential confounders (individual socio-economic position and calendar year of diagnosis) and stratified for age. In addition, we performed different sensitivity analyses.ResultsWe identified 1571 cases and randomly selected 6284 referents. After adjustment, women who participated in PMSP had a 51 % lower risk of breast cancer-specific mortality compared to those who did not (adjusted odds ratio [aOR] =0.49, 95 % CI: 0.44–0.55). Sensitivity analyses did not markedly change the estimated associations. Correction for self-selection bias reduced the effect size, but the estimate remained significant.ConclusionOur results indicate that in a context of high opportunistic screening rates, participation in breast cancer screening program substantially reduces breast cancer-specific mortality. For policy, these results should be balanced against the potential harms of screening, including overdiagnosis and overtreatment.