Cancer Causes & Control

To determine whether accounting for the time dynamics of diabetes exposure will change the risk estimates for colorectal cancer. We analyzed data from the 45, 516 women enrolled in the BCDDP follow-up cohort study. We used proportional hazards regression to obtain multivariable-adjusted risk estimates for incident colorectal cancer for prevalent diabetes at baseline and diabetes as a time-dependent variable. Subjects with diabetes had a statistically significant increased risk of colorectal cancer compared to subjects without diabetes (RR = 1.60, 95% CI 1.18–2.18). When we defined exposure as duration of diabetes exposure at cohort exit, we found that in the first 4 years after diagnosis risk was essentially the same as in those never having had a diagnosis of diabetes. For those who had been diagnosed between 4 and 8 years previously, however, we observed a RR of 2.36 (95% CI 0.96–5.79), while longer duration of exposure was associated with smaller and then no change in risk compared to those without a diagnosis of diabetes. These results are consistent with the theory that hyperinsulinemia can explain, at least in part, the association of diabetes with colorectal cancer, but in a time-dependent manner.

Objectives: We investigated p53 gene mutations in advanced gastric cancers by direct DNA sequencing, in order to determine the frequency of mutations in gastric cancers having different epidemiological backgrounds, tumors of the cardia were compared with those arising in the antrum or corpus. Intestinal type cancers were compared with diffuse or other histologic types. We have chosen to assess the frequency of mutations solely based on DNA sequencing. Methods: Paraffin embedded tissues from 100 gastric cancers were evaluated. The mutational status of the p53 gene in exons 5 through 9 were determined by direct sequencing of PCR products. Results: Mutations in exons 5, 6, 7 and 8 were found in 35 of 100 (35%) stomach cancers. One tumor had mutations in both exons 5 and 8. No mutations were detected in exon 9. p53 gene mutations were significantly more frequent in cancers of the cardia (19/35; 54%) than the antrum and corpus (16/65 (25%)) (p ≤ 0.005). p53 mutations were more frequent in intestinal type cancers (28/67; 42%) than diffuse cancers or other histologic types of cancer (7/33; 21%), but the difference was not statistically significant. Conclusions: Cancers of the cardia more frequently contain p53 mutations than do antral and corpus cancers, suggesting that cancers in the proximal and distal stomach evolve through different molecular pathways.

Adverse childhood experiences (ACEs) have been associated with higher odds of cancer in adulthood. One potential explanation for this association is the impact of ACEs on cancer screening. To address this shortcoming, this study examined how ACEs were associated with current compliance and ever use of prostate, breast, cervical, and colorectal cancer screening. Data from the 2014 Kansas Behavioral Risk Factor Surveillance System were used (n = 11,794). Logistic regressions were used to calculate odds of cancer screening behaviors from each of nine different ACE items and a count of ACEs. Individual ACE items were associated with lower odds of compliance with PSA screening, clinical breast exam, and pap test guidelines. Certain ACEs were associated with increased odds of compliance with colorectal cancer screening guidelines among women and lower odds of compliance among men. ACEs were associated with ever screening for PSA and ever use of colonoscopy or sigmoidoscopy among men and women. Physical abuse was most consistently associated with cancer screening, across outcomes. Most significant associations showed that specific ACEs were associated with lower odds of cancer screening. Therefore, efforts should be made to promote screening among those with histories of ACEs.

Objectives: The aim of this study was to explore the association between traumatic brain injury and brain tumor development. Methods: A cohort of patients hospitalized for traumatic brain injury during 1965–1994 was compiled using the Swedish Inpatient Register. Complete follow-up through 1995 was attained through record linkage with the Swedish Cancer Register, the Cause of Death Register, and the Emigration Register. Standardized incidence ratios (SIRs), defined as the ratios of the observed to the expected numbers of brain tumors, were used as the measure of relative risk. The expected number of brain tumors was calculated by multiplying the observed person-time by age-, gender- and calendar year-specific incidence-rates derived from the general Swedish population. Results: The cohort included 311,006 patients contributing 3,225,317 person-years. A total of 281 cases of brain tumors were diagnosed during follow-up. No associations were found between traumatic brain injury and the risk of primary brain tumors, neither overall (SIR: 1.0; 95% confidence interval (CI): 0.9–1.2), nor in analyses broken down by main groups of brain tumors. Stratified analyses according to age at entry into the cohort, year of follow-up, and severity of the brain injury all showed essentially the same null results. Conclusion: No association between traumatic head injury and primary brain tumors has been found.

To investigate socioeconomic disparities in epithelial ovarian cancer (EOC) survival in Sweden. A cohort of 635 women with invasive EOC who participated in a nationwide population-based case–control study was included in the present population-based prospective study. Women were diagnosed with EOC between 1993 and 1995. Mortality until 31 December 2007 was determined through linkage with the Swedish Cause of Death Registry. Clinical data (tumor stage and tumor differentiation) and indicators of socioeconomic status (SES, education level, and annual individual disposable income) were retrieved from medical records and a nationwide database, respectively. The Cox proportional hazards regression model and the Laplace regression model were used to estimate the effect of clinical factors and SES on EOC survival. The main factors associated with EOC survival were tumor stage and tumor differentiation: women with stage II, III, and IV tumors had a greater mortality risk than those with stage I tumors [hazard ratio (HR) 2.65, 95 % confidence interval (CI) 1.73–4.07; HR 6.69, 95 % CI 4.85–9.22; HR 12.84, 95 % CI 8.90–18.66, respectively]. After adjustment for these tumor characteristics, no clear association remained between our indicators of SES and EOC survival, but better survival was observed among women with stage IV tumors and a higher income level, and among women with poorly differentiated tumors and a higher education level. Nevertheless, there was no evidence of extended survival among women with higher compared to lower SES. Our study provides no convincing evidence of an association between SES and EOC survival in Sweden.

Lifestyle factors such as smoking, alcohol, body weight, physical activity, and diet quality have been associated with the risk of pancreatic cancer. However, studies of their combined association in women are limited. Data on smoking habits, alcohol intake, diet composition, recreational physical activity, body weight, and waist circumference, obtained at recruitment for 136,945 postmenopausal women (aged 50–79 years) participating in the Women’s Health Initiative study, were categorized separately, with higher scores for each variable assigned to the categories representing healthier behaviors. The combined healthy lifestyle index (HLI) score, created by summing the scores for each risk factor, was grouped into quartiles. We used multivariable-adjusted Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for pancreatic cancer risk in association with the HLI. Over an average follow-up period of approximately 16.0 years, 1,119 incident cases of pancreatic cancer were ascertained. Compared to women in the lowest HLI quartile, those in the upper quartiles (qt) had a reduced risk of pancreatic cancer (multivariable-adjusted HRqt3rd 0.83, 95% CI 0.74–0.99; and HRqt4th 0.74, 95% CI 0.62–0.88, respectively, p trend = 0.001). Use of waist circumference instead of BMI in the HLI score yielded similar results. Among women who were either non-diabetic or non-smokers, high HLI was also associated with reduced risk (HRqt4th 0.78, 95% CI 0.65–0.85 and HRqt4th 0.80, 95% CI 0.66–0.97, respectively). Stratification by BMI categories (18.5− < 25.0, 25.0− < 30.0 and > 30.0 kg/m2) showed similar results in all groups. Our findings suggest that in postmenopausal women, a healthy lifestyle is associated with reduced risk of pancreatic cancer.