The impact of preexisting comorbidities on receipt of cancer therapy among women with Stage I-III breast cancer in the Detroit Research on Cancer Survivors cohort

PURPOSE

Pre-existing comorbidities play an important role in choice of cancer treatment. We retrospectively evaluated the relationship between pre-existing comorbidities and receipt of local and systemic therapy in a cohort of Black women with Stage I-III breast cancer.

METHODS

The study population for analysis included 1169 women with Stage I-III disease enrolled in the Detroit Research on Cancer Survivors (ROCS) cohort. Information on comorbidities, socio-demographic, and clinical variables were obtained from self-reported questionnaires and the cancer registry. Comorbidities were analyzed individually, and comorbidity burden was categorized as low (0-1), moderate (2-3) or high (≥4). We used logistic regression analysis to evaluate factors associated with receipt of local treatment (surgery ± radiation; N = 1156), hormonal (N = 848), and chemotherapy (N = 680). Adjusted models included variables selected a priori that were significant predictors in univariate analysis.

RESULTS

Receipt of treatment was categorized into local (82.6%), hormonal (73.7%), and/or chemotherapy (79.9%). Prior history of arthritis and depression were both associated with a lower likelihood to receive local treatment, [odds ratio (OR), 95% confidence interval (CI), 0.66, 0.47-0.93, and 0.53, 0.36-0.78], respectively. Obesity was associated with higher likelihood of receiving hormonal therapy (OR: 1.64, 95% CI: 1.19, 2.26), and heart failure a lower likelihood (OR: 0.46, 95% CI: 0.23, 0.90). Older age (Ptrend  <0.01) and increasing co-morbidity burden (Ptrend  = 0.02) were associated with lower likelihood of receiving chemotherapy.

CONCLUSION

History of prior co-morbidities has a potentially detrimental influence on receipt of recommended cancer-directed treatment among women with Stage I-III breast cancer.

Diabetes mellitus in relation to colorectal tumor molecular subtypes: A pooled analysis of more than 9000 cases

Diabetes is an established risk factor for colorectal cancer. However, colorectal cancer is a heterogeneous disease and it is not well understood whether diabetes is more strongly associated with some tumor molecular subtypes than others. A better understanding of the association between diabetes and colorectal cancer according to molecular subtypes could provide important insights into the biology of this association. We used data on lifestyle and clinical characteristics from the Colorectal Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), including 9756 colorectal cancer cases (with tumor marker data) and 9985 controls, to evaluate associations between reported diabetes and risk of colorectal cancer according to molecular subtypes. Tumor markers included BRAF and KRAS mutations, microsatellite instability and CpG island methylator phenotype. In the multinomial logistic regression model, comparing colorectal cancer cases to cancer-free controls, diabetes was positively associated with colorectal cancer regardless of subtype. The highest OR estimate was found for BRAF-mutated colorectal cancer, n = 1086 (ORfully adj : 1.67, 95% confidence intervals [CI]: 1.36-2.05), with an attenuated association observed between diabetes and colorectal cancer without BRAF-mutations, n = 7959 (ORfully adj : 1.33, 95% CI: 1.19-1.48). In the case only analysis, BRAF-mutation was differentially associated with diabetes (Pdifference  = .03). For the other markers, associations with diabetes were similar across tumor subtypes. In conclusion, our study confirms the established association between diabetes and colorectal cancer risk, and suggests that it particularly increases the risk of BRAF-mutated tumors.