According to a study published in the Journal of the National Cancer Institute, eight cycles of preoperative chemotherapy was no better than six cycles in women with early breast cancer who had responded to two initial cycles, according to data from a randomized controlled trial. Additionally, women who failed to respond to the first two cycles of one drug combination did not benefit from switching to a different drug combination for four additional cycles, compared with those who continued receiving the original combination for four more cycles.

Preoperative chemotherapy, also known as neoadjuvant chemotherapy, is used to shrink the tumor to improve surgical options and provide early information about a patient's response to treatment.

In a randomized controlled trial, Gunter von Minckwitz, M.D., of the Universitas-Frauenklinik in Frankfurt and colleagues in the German Breast Group treated 2,090 women with two cycles of preoperative docetaxel, doxorubicin, and cyclophosphamide (TAC). The researchers then randomly assigned the 1,390 women whose tumors responded to therapy to either four or six additional cycles of TAC. The proportion of women who had a complete pathological response was similar in the two arms, 21 percent and 23.5 percent, respectively.

The 622 women who failed to respond to the initial two cycles of TAC were randomly assigned to either four additional cycles of TAC or four cycles of capecitabine plus vinorelbine (NX). Increasing the number of TAC cycles or switching regimens did not appear to improve outcomes. Only 5.3 percent of women on TAC achieved a complete pathological response and 6.0 percent of the women on NX.

In an accompanying editorial, Francisco J. Esteva, M.D., Ph.D., and Gabriel N. Hortobagyi, M.D., of the University of Texas M. D. Anderson Cancer Center in Houston review the results of the German trial and other trials that tested neoadjuvant therapy. The data indicate that neoadjuvant therapy is effective and that the full benefit can be achieved with a limited number of treatment cycles. Not all women benefit equally though, and therefore new treatment approaches are needed.

"Patients who do not respond to the initial chemotherapy should be considered for alternative treatment approaches, if possible as part of a clinical trial," the editorialists write.

SOURCE:
Journal of the National Cancer Institute, April 8, 2008