Adjuvant chemo affects bone density in postmenopausal breast cancer patients

Among postmenopausal women with early-stage breast cancer, bone density is lower in those who are given adjuvant chemotherapy than in those who are not, according to a report in the June 1st issue of the American Journal of Medicine.

“Adjuvant chemotherapy for breast cancer can have adverse effect on bone,” Dr. Nancy C. Greep and colleagues from The John Wayne Cancer Institute, in Santa Monica, California, note. To investigate the effects of adjuvant chemotherapy on bone density in postmenopausal women treated for stage I or II breast cancer, the researchers conducted a chart review of 130 such patients who had spine or hip bone density measured by dual-energy x-ray absorptiometry. Thirty-six (28%) of the 130 patients had received adjuvant chemotherapy. Compared to the 94 (72%) patients who had not received adjuvant chemotherapy, those who had received the treatment had significantly lower mean adjusted bone density at the total hip (p = 0.0002), femur (p = 0.009), trochanter (p = 0.003), anteroposterior spine (p = 0.05), and lateral spine (p = 0.009). “Bone density for age scores were approximately 0.5 SD lower in patients who had received adjuvant chemotherapy than in those who had not,” Dr. Greep and colleagues explain. “Because the risk of fracture approximately doubles for each standard deviation decrease in bone density, this is roughly equivalent to about a 40% increase in the future risk of fracture.” In the discussion section of their paper, the researchers note that bisphosphonates have decreased the development of bone metastases in breast cancer patients. The current findings might add to the rationale for such treatment, they say.(Source: Am J Med 2003;114:653-659: Reuters Health: June 18, 2003: Oncolink)