By Merritt McKinney 

NEW YORK, Feb 21 (Reuters Health) - Older women with breast cancer are less likely to receive recommended diagnostic testing and treatment and more likely to die than younger women, according to a new study.  

The differences may result in part from the higher rate of other illnesses, like diabetes, stroke and liver disease, that affect older women, although more research is needed to understand the connection between these so-called comorbidities and breast cancer diagnosis, treatment and survival, the study's lead author told Reuters Health in an interview. 

Dr. Rosemary Yancik, of the National Institute on Aging in Bethesda, Maryland, and colleagues studied 1,800 postmenopausal women who had been diagnosed with breast cancer. The researchers divided the women into three age groups: 55 to 64 years, 65 to 74 years and 75 years and older.  

The team detected several differences in the diagnosis, treatment and survival among older women, according to their report in the February 21^st issue of the Journal of the American Medical Association. While most women with early-stage breast cancer received treatment that fit national guidelines, older women were less likely to receive recommended care. For instance, older women were less likely to receive radiation therapy after having a partial mastectomy.  

Older women were also less likely to undergo a diagnostic procedure called axillary lymph node dissection, Yancik and her colleagues report. After a breast tumor is surgically removed, doctors often look for cancer in axillary (armpit) lymph nodes to assess survival odds. Women 70 and older were significantly less likely to undergo this procedure.  

Why older women were less likely to undergo axillary lymph node dissection is uncertain, according to the researchers. Some patients might have been too sick to undergo the procedure, while others may not have been offered the option, they note.  

Older women also had poorer survival odds during the 30-month study. The risk of dying from early-stage breast cancer increased with age. Women aged 75 and older were more than twice as likely to die as younger women, according to the report. However, age did not appear to affect a woman's chances of surviving late-stage breast cancer.  

Having other illnesses in addition to breast cancer also increased women's odds of dying. The risk was more than doubled in women who had kidney failure, liver disease or stroke. On average, older women were more likely to have other health problems besides breast cancer. In fact, women aged 75 and older were more likely to die from other causes than from breast cancer during the study.  

"Age and comorbidity limit diagnostic tests and examinations, narrow treatment choices and are associated with risk of early (death) in postmenopausal women with breast cancer," Yancik and her colleagues conclude. 

The relationship between comorbidities and breast cancer in older women is complex, Yancik told Reuters Health in an interview. It is hard to tell from studies exactly what doctors face in diagnosing and treating breast cancer in older women, who may have a number of other diseases or disabilities, she said. More research is needed to "get a handle" on how aging and comorbidities affect breast cancer care, she said. 

SOURCE: Journal of the American Medical Association 2001;285:885-892.