Impact of comorbidity on management and mortality in women diagnosed with breast cancer

• To investigate associations between comorbidity burden, management, and mortality in women with breast cancer. A total of 42,646 women diagnosed with breast cancer between 1992 and 2008 were identified in two Clinical Quality Registers in Central Sweden. Breast cancer-specific, conditional breast cancer, competing-cause and all-cause mortality were estimated in relation to comorbidity burden assessed by the Charlson comorbidity index. All analyses were stratified by stage at diagnosis using competing risk analyses, and all-cause mortality was estimated as a function of follow-up time. Following adjustment for age and calendar period, breast conserving surgery was significantly less likely to be offered to women with severe comorbidity (OR 0.63; 95 % CI 0.58-0.69). Similarly, the proportion treated with radiotherapy, tamoxifen, or chemotherapy was lower in women with severe compared to those with no comorbidity. In women with early stage disease, breast cancer-specific mortality was higher among patients with severe comorbidity (sHR 1.47; 95 % CI 1.11-1.94). In all stages of breast cancer, conditional breast cancer and competing-cause mortality were elevated in women with severe comorbidity. For all stages, the relative risk of all-cause mortality between women with severe versus no comorbidity varied by time since diagnosis, and was most pronounced at early follow-up. Comorbidity affects treatment decisions and mortality. In women with early stage breast cancer, severe comorbidity was associated not only with conditional breast cancer, competing-cause and all-cause mortality, but also breast cancer-specific mortality. The observed differences in breast cancer-specific mortality may be due to less extensive treatment, impaired tumor defense and differences in general health status and lifestyle factors.

Keyword

Breast neoplasm

Comorbidity

Competing risk

Treatment

Mortality

Publication and Content Type

ref (subject category)

art (subject category)