Chemo "can't level the playing field" for triple negative breast cancer

NEW YORK (Reuters Health) - T1N0 breast tumors that are negative for estrogen and progesterone receptors and her2/neu (i.e., triple negative breast cancer) have a higher risk of recurrence despite aggressive adjuvant chemotherapy, according to a report in the September/October issue of The Breast Journal.

"This is an aggressive tumor that should be treated aggressively, even at these early stages," Dr. Henry G. Kaplan from Swedish Medical Center in Seattle, Washington, told Reuters Health by email. "We still have no data on how effective adjuvant treatment is at this stage, however."

Dr. Kaplan and colleagues calculated recurrence risk and patterns of recurrence specific to 110 women who had T1N0 triple negative breast cancer and compared them with 919 women who had hormone receptor-positive, her2/neu-negative breast cancer.

Compared with the other patients, women with triple negative breast cancer were more often treated with adjuvant chemotherapy and aggressive regimens, the authors report.

Recurrence rates after a median 4.2 years of follow-up were significantly higher in the triple negative group (8.2%) than in the hormone receptor-positive, her2/neu-negative group (1.2%).

When broken down by T-stage, recurrence rates were higher in the triple negative group for T1b (8.7% versus 0) and T1c (8.8% versus 2.1%). There were no recurrences among T1a women in either group.

Five-year overall survival was significantly greater in the hormone receptor-positive patients (96%) than in the triple negative patients (92%), and the average time to recurrence was higher among hormone receptor-positive, her2/neu-negative patients (2.8 years) than among triple negative patients (1.9 years).

At 5 years, relapse-free survival rates were 98% in the hormone receptor-positive women and 89% in the triple negative group.

"We are recommending adjuvant chemo for T1b and greater stages," Dr. Kaplan said. "We know that certain chemo drugs are very active in triple negative disease (e.g., anthracyclines, alkylators, Platinol, Gemzar), but the relapse rates are high. We need to know if adding newer agents will make a difference (e.g., bevacizumab, PARP inhibitors)."

"The experience reported here suggests not only that systemic therapy is indicated, but that chemotherapy fails to level the playing field," writes Dr. Robert Livingston from University of Arizona, Tucson, in a related editorial. "More than 10% of these node-negative, small tumors are destined to relapse in spite of its use, if the patient is unlucky enough to have triple negative biology."

Breast J 2009;15:451-460.

Copyright © 2009 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.