Influence of age and comorbidity on treatment choice and survival in elderly patients with breast cancer.

To determine the effect of age and comorbid diseases on treatment choice and survival, the medical records of 300 breast cancer patients of 55 years and older were reviewed. All patients were admitted to the Netherlands Cancer Institute (NKI) for first treatment between 1980 and 1987. Patients were classified according to severity level of comorbid diseases. Physicians were found to treat women of 75 years and older less often with adjuvant radiotherapy after a mastectomy, and more often to employ only primary endocrine treatment for local stage disease, as compared with younger patients. According to the treatment guidelines of the institute, the study sample was divided into patients who received standard vs. non-standard treatment. The treatment of 38 women (13.1%) did not correspond with the guidelines. Of these, 84% were 75 years and older and 50% had a severe comorbidity status. Logistic regression analysis indicated that advanced age, per se, was a better indicator of the risk of not being treated according to protocol than the comorbidity status. Cox multivariate analyses demonstrated that neither the severity of the comorbidity status nor the differences in treatment between younger and older patients had a significant effect on the risk of dying from breast cancer or on the risk of developing recurrences. In this analysis, age 75 years or more proved to be a significant and independent predictor of a worse overall and disease-specific survival as compared to age between 65-74 years.