Four as Good as Six
This report suggests that four cycles of AC chemotherapy are just as effective as six cycles for women with newly diagnosed low-risk breast cancer. Good news indeed. And absolutely more evidence of how things continuously change in Cancer World. I have been around long enough to see all kinds of scheduling and protocals. For a period of close to 10 years, there was a great deal of interest in the sequence of adjuvant chemotherapy and radiation therapy for newly diagnosed women. There were clinical trials comparing chemo first, radiation first, concurrent chemo and radiation, and "sandwich" treatments (meaning three chemo, radiation, three more chemo). I well remember how the women on the "sandwich" schedule hated it. Having to come back for more chemo, having your just-starting-to-grow-in hair fall out again, was horrible.
Apparently, all those trials decided that chemo first, then radiation is the best way to go as that has been the standard of care for years now. Here is the abstract and then a link from this new study from the Journal of Clinical Oncology:
Six Cycles of Doxorubicin and Cyclophosphamide or Paclitaxel Are Not Superior to Four Cycles As Adjuvant Chemotherapy for Breast Cancer in Women With Zero to Three Positive Axillary Nodes: Cancer and Leukemia Group B 40101
Lawrence N. Shulman, Constance T. Cirrincione, Donald A. Berry, Heather P. Becker, Edith A. Perez, Ruth O'Regan, Silvana Martino, James N. Atkins, Erica Mayer, Charles J. Schneider, Gretchen Kimmick, Larry Norton, Hyman Muss, Eric P. Winer, and Clifford Hudis
The ideal duration of adjuvant chemotherapy for patients with lower risk primary breast cancer is not known. Cancer and Leukemia Group B trial 40101 was conducted using a phase III factorial design to define whether six cycles of a chemotherapy regimen are superior to four cycles. We also sought to determine whether paclitaxel (T) is as efficacious as doxorubicin/cyclophosphamide (AC), but with reduced toxicity.
Patients and Methods
Between 2002 and 2008, the study enrolled women with operable breast cancer and zero to three positive nodes. Patients were randomly assigned to either four or six cycles of either AC or T. Study stratifiers were estrogen receptor/progesterone receptor (ER/PgR), human epidermal growth factor receptor 2 (HER2), and menopausal status. After 2003, all treatment was administered in dose-dense fashion. The primary efficacy end point was relapse-free survival (RFS).
A total of 3,171 patients were enrolled; 94% were node-negative and 6% had one to three positive nodes. At a median follow-up of 5.3 years, the 4-year RFS was 90.9% and 91.8% for six and four cycles, respectively. The adjusted hazard ratio (HR) of six to four cycles regarding RFS was 1.03 (95% CI, 0.84 to 1.28; P ! .77). The 4-year OS was 95.3% and 96.3% for six and four cycles, respectively, with an HR of six to four cycles of 1.12 (95% CI, 0.84 to 1.49; P ! .44). There was no interaction between treatment duration and chemotherapy regimen, ER/PgR, or HER2 status on RFS or OS.
For women with resected primary breast cancer and zero to three positive nodes, we found no evidence that extending chemotherapy regimens of AC or single-agent T from four to six cycles improves clinical outcome.
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