Chemotherapy After Complete Surgical Removal of Local or Regional Breast Cancer Recurrence Increased Survival Rates

This abstract will be presented at a press conference hosted by Carlos L. Arteaga, M.D. associate director for clinical research and director of the Breast Cancer Program at Vanderbilt Ingram Cancer Center, on Thursday, Dec. 6 at 7:30 a.m. CT in Room 217 A-C of the Henry B. Gonzales Convention Center. Reporters who cannot attend in person can call in using the following information:• U.S./Canada (toll free): 1 (800) 446-2782• International (toll call): 1 (847) 413-3235

Newswise — SAN ANTONIO — Chemotherapy after surgery, or adjuvant chemotherapy, led to higher rates of disease-free and overall survival for women with isolated local or regional recurrence of breast cancer, according to data presented at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium, held here Dec. 4-8.

Patients with isolated local and/or regional recurrence of their breast cancers are at high risk for developing metastases in other areas of the body. Some physicians administer chemotherapy to these patients after their recurrent tumors have been completely removed by surgery, but the efficacy of this treatment had not been studied until now.

“This is the first randomized controlled study that shows that adjuvant chemotherapy works in these patients,” said Stefan Aebi, M.D., head of the division of medical oncology at Luzerner Kantonsspital in Luzern, Switzerland.

He and his colleagues from the Breast International Group, the National Surgical Adjuvant Breast and Bowel Project and the International Breast Cancer Study Group evaluated 162 patients with isolated local and regional recurrence; 85 received adjuvant chemotherapy and 77 did not.

Five-year disease-free survival rates were 69 percent for women who received adjuvant chemotherapy and 57 percent for those who did not. The overall survival rate was 88 percent for women who received chemotherapy compared with 76 percent for those who did not.

Women with estrogen receptor (ER)-negative breast cancer demonstrated the greatest benefit, with a five-year disease-free survival rate of 67 percent among those who received chemotherapy versus 35 percent among those who did not. In addition, within this group, overall survival rates were 79 percent among those who received chemotherapy and 69 percent among those who did not.

For patients with ER-positive disease, five-year disease-free survival was 70 percent for those who received chemotherapy versus 69 percent for those who did not. Overall survival was 94 percent for those patients with ER-positive disease who received chemotherapy versus 80 percent among those who did not.

Aebi recommended that physicians prescribe adjuvant chemotherapy for patients with isolated local and regional recurrence of breast cancer, especially if the recurrence is ER-negative and therefore not sensitive to endocrine therapy.

This research was funded by the National Cancer Institute, the Swiss Cancer League and other national cancer research agencies.

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The mission of the 2012 CTRC-AACR San Antonio Breast Cancer Symposium is to produce a unique and comprehensive scientific meeting that encompasses the full spectrum of breast cancer research, facilitating the rapid translation of new knowledge into better care for patients with breast cancer. The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio, the American Association for Cancer Research (AACR) and Baylor College of Medicine are joint sponsors of the San Antonio Breast Cancer Symposium. This collaboration utilizes the clinical strengths of the CTRC and Baylor and the AACR’s scientific prestige in basic, translational and clinical cancer research to expedite the delivery of the latest scientific advances to the clinic. For more information about the symposium, please visit www.sabcs.org.

Abstract:Publication Number: S3-2

Title: Chemotherapy prolongs survival for isolated local or regional recurrence of breast cancer: The CALOR trial (Chemotherapy as Adjuvant for Locally Recurrent breast cancer; IBCSG 27-02, NSABP B-37, BIG 1-02) Stefan Aebi1, Shari Gelber1, István Láng1, Stewart J Anderson2, André Robidoux2, Miguel Martín3, Johan WR Nortier3, Eleftherios P Mamounas2, Charles E Geyer, Jr.2, Rudolf Maibach1, Richard D Gelber1, Norman Wolmark2 and Irene L Wapnir2. 1International Breast Cancer Study Group, Bern, Switzerland; 2National Surgical Adjuvant Breast and Bowel Project, Pittsburgh, PA and 3Breast International Group, Brussels, Belgium.

Body: Introduction Patients with isolated local and regional recurrences (ILRR) of breast cancer (BC) have a high risk of developing distant metastasis and dying from BC. We investigated the impact of chemotherapy (C) on disease-free survival (DFS) and overall survival (OS) after ILRR.

Methods: Patients with resected ILRR were stratified according to prior chemotherapy (yes vs. no), ER and/or PgR status of the recurrent tumor (both negative vs. either positive), and location of recurrence (breast vs. scar/chest wall vs. lymph nodes). Radiation, hormone and HER2 directed therapies were delineated in the protocol. Participants were randomly assigned to receive C or none. Multidrug C for at least 4 courses was recommended. Drug selection was at the discretion of the investigator. Slow accrual led to premature closure of the trial before achieving the planned sample size of 265.

Results: The trial accrued 162 patients (C, 85; control, 77) from 2002-2010. The groups were balanced in regard to the characteristics listed in the table below.

At a median follow up of 4.9 years, there were 24 (28%) DFS events and 9 (11%) deaths in the C group compared with 34 (44%) DFS events and 21 (27%) deaths in the control group, corresponding to a 5-year DFS of 69% vs. 57%, [DFS HR (C/control) = 0.59, 95% CI (0.35, 0.99)], p =0.046] and a 5-year OS of 88% vs. 76%, [OS HR (C/control) = 0.41, 95% CI (0.19, 0.89)], p =0.02]. The results remained significant for both DFS and OS in multivariable Cox proportional hazards modeling controlling for ILRR location, disease-free interval, ER status and prior adjuvant chemotherapy. Adjuvant C was particularly effective for women with ER-negative ILRR: 5-year DFS 67% vs. 35%, [DFS HR (C/control) = 0.32, 95% CI (0.14, 0.73)], p =0.007] and OS 79% vs. 69%, [OS HR (C/control) = 0.43, 95% CI (0.15, 1.24)], p =0.12]. Results for the ER-positive ILRR cohort were: 5-year DFS 70% vs. 69%, [DFS HR (C/control) = 0.94, 95% CI (0.47, 1.89)], p =0.87] and OS 94% vs. 80%, [OS HR (C/control) = 0.40, 95% CI (0.12, 1.28)], p =0.12].

Conclusion: Adjuvant chemotherapy should be recommended for patients with completely resected isolated loco-regional recurrences of breast cancer, in particular, if the recurrence is not sensitive to endocrine therapy.

Funding: NCI PHS grants U10-CA-37377, -69974, -12027, -69651, CA-75362.