Side effects of breast cancer treatment offer research direction

COLUMBUS, Ohio -- In a sweeping review of 25 years of research into the side effects of adjuvant treatment for breast cancer (chemotherapy and/or radiation following surgery), an Ohio State University cancer specialist concludes that adjuvant therapy reduces mortality, most of the side effects are reversible, and there is little or no increase in long-term cardiac toxicity and second cancers using current regimens.

The conclusions are published in the June 28 edition of The New England Journal of Medicine.

Dr. Charles L. Shapiro, director of breast medical oncology at the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, conducted the review. "Today a majority of women diagnosed with early stage breast cancer will be breast cancer survivors," says Shapiro. "At the same time, we have lowered the threshold for treating these women with adjuvant therapy such that it is becoming increasingly important to understand the short- and long-term side effects of the treatments."

Among the findings:

• Weight gain and chemotherapy-induced ovarian failure are common problems in younger women. Shapiro says ovarian failure -- when a woman's ovaries stop producing estrogen and she goes through menopause at an earlier age than expected -- is important because it can lead to osteopenia, osteoporosis and possibly cardiovascular disease. He concludes that patients with ovarian failure should take calcium supplements and vitamin D, engage in weight-bearing exercises, have their bone density measured, and if the bone mineral density is low, consider bisphosphonate therapy.
• Taxanes, such as Taxol and Taxotere, are increasingly being incorporated into adjuvant treatment for early stage breast cancer although there is little information on the long-term side effects of these drugs.
• There does not seem to be any detectable long-term increase in heart damage when women receive Adriamycin in standard doses of adjuvant chemotherapy.

"It used to be that we didn't have the luxury of considering long term side effects," says Shapiro. "But now, more women are surviving, and survivorship issues are of major importance."

Shapiro and co-author Dr. Abram Recht of Beth Israel Deaconess Medical Center in Boston point out that the ideal adjuvant treatment regimen has yet to be defined, and researchers need to work on defining predictive factors in choosing the right regimen for a particular patient.

He also says that the newer targeted drugs, such as Herceptin, should not be used for early stage breast cancer outside of a clinical trial setting. Trials of Herceptin in combination with adjuvant chemotherapy are ongoing to determine the effectiveness of the combination and, importantly, the long-term side effects.

Contact: Michelle Gailiun, Medical Center Communications, 614-293-3737, or Gailiun.1@osu.edu

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