Women in the older age groups with preexisting diseases also tended to receive less aggressive cancer treatment, according to the study. Of those who received partial mastectomies, older patients received radiation therapy less frequently. Poor health status may interact with the breast cancer and its treatment, increasing the severity of other conditions and the risk of death from causes other than breast cancer, according to the study. More research is crucial to determine if treatment should differ according to age and health status, say the authors. In addition, Yancik advocates research and development of an assessment tool a comorbidity index that clinicians can use to communicate with each other about the influence of age-related diseases on the cancer.
Breast cancer is second only to lung cancer as the most common cause of cancer death in women.
Two-thirds of breast cancer cases occur in women over 55, with the highest rates of breast cancer occurring in women aged 70 to 84 years. Breast cancer could become an even greater public health concern as the proportion of women over 65 increases from the current 14.5 percent to 21.3 percent in 2030. The study is part of a series of collaborative investigations by the NIA s Epidemiology, Demography, and Biometry Program and the NCI SEER Program to determine the impact of preexisting diseases on treatment of various types of cancer. In 1997, Yancik and her colleagues published a similar study on colon cancer. The NIA and the NCI are two of the 26 institutes and centers at the National Institutes of Health.