Publication
Low-Dose Oral Cyclophosphamide and Methotrexate Maintenance For Hormone Receptor-Negative Early Breast Cancer: International Breast Cancer Study Group Trial 22-00
Journal Paper/Review - Jun 20, 2016
Colleoni Marco, Eniu Alexandru, Cagossi Katia, Rauch Daniel, Chirgwin Jacquie, Gelber Richard D, Regan Meredith M, Coates Alan S, Price Karen N, Viale Giuseppe, Kralidis Elena, Tondini Carlo, Gray Kathryn P, Gelber Shari, Láng István, Thürlimann Beat, Gianni Lorenzo, Abdi Ehtesham A, Gomez Henry L, Linderholm Barbro K, Puglisi Fabio, Goldhirsch Aron
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Electronic
Brief description/objective
PURPOSE
To evaluate the benefit of low-dose cyclophosphamide and methotrexate (CM) maintenance, which previously demonstrated antitumor activity and few adverse effects in advanced breast cancer, in early breast cancer.
PATIENTS AND METHODS
International Breast Cancer Study Group (IBCSG) Trial 22-00, a randomized phase III clinical trial, enrolled 1,086 women (1,081 intent-to-treat) from November 2000 to December 2012. Women with estrogen receptor- and progesterone receptor-negative (< 10% positive cells by immunohistochemistry) early breast cancer any nodal and human epidermal growth factor receptor 2 status, were randomly assigned anytime between primary surgery and 56 days after the first day of last course of adjuvant chemotherapy to CM maintenance (cyclophosphamide 50 mg/day orally continuously and methotrexate 2.5 mg twice/day orally on days 1 and 2 of every week for 1 year) or to no CM. The primary end point was disease-free survival (DFS), which included invasive recurrences, second (breast and nonbreast) malignancies, and deaths.
RESULTS
After a median of 6.9 years of follow-up, DFS was not significantly better for patients assigned to CM maintenance compared with patients assigned to no CM, both overall (hazard ratio [HR], 0.84; 95% CI, 0.66 to 1.06;P = .14) and in triple-negative (TN) disease (n = 814; HR, 0.80; 95% CI, 0.60 to 1.06). Patients with TN, node-positive disease had a nonstatistically significant reduced HR (n = 340; HR, 0.72; 95% CI, 0.49 to 1.05). Seventy-one (13%) of 542 patients assigned to CM maintenance did not start CM. Of 473 patients who received at least one CM maintenance dose (including two patients assigned to no CM), 64 (14%) experienced a grade 3 or 4 treatment-related adverse event; elevated serum transaminases was the most frequently reported (7%), followed by leukopenia (2%).
CONCLUSION
CM maintenance did not produce a significant reduction in DFS events in hormone receptor-negative early breast cancer. The trend toward benefit observed in the TN, node-positive subgroup supports additional exploration of this strategy in the TN, higher-risk population.