Table 6. Standard Adjuvant Chemotherapy Regimens for Stage I, II, IIIA, and Operable IIICHER2/neuNon-Overexpressing Breast Cancer continued...
Several investigators have attempted to improve outcomes by combining CMF and anthracycline-containing regimens. Two Italian studies have evaluated these regimens.[165,166] In one study, 490 premenopausal and postmenopausal women with one to three axillary lymph nodes were randomized to receive CMF (12 cycles) or CMF (eight cycles) followed by doxorubicin (four cycles). After a median observation of 17.5 years, no statistically significant difference was documented in the first study (relapse-free survival [RFS], HR, 1.06; total survival, HR, 1.03). In contrast, the delivery of doxorubicin first, followed by CMF significantly reduced the risk of disease relapse (HR, 0.68; 95% CI, 0.54–0.87; P =.0017) and death (HR, 0.74; 95% CI, 0.57–0.95; P = .018) compared with the alternating regimen. In the other study, 403 premenopausal and postmenopausal women with four or more positive axillary lymph nodes were randomized to receive doxorubicin (four cycles) followed by CMF (eight cycles) or CMF (two cycles) alternating with doxorubicin (one cycle) for a total of 12 cycles. Women who received doxorubicin followed by CMF had better RFS (42% vs. 28%; P = .002) and OS (58% vs. 44%; P = .002).[Level of evidence: 1iiA]
The NSABP-B-15 trial randomized 2,194 patients with axillary node-positive breast cancer and tumors determined nonresponsive to tamoxifen to doxorubicin and cyclophosphamide (AC) (four cycles), CMF (six cycles), or AC (four cycles) followed after a 6-month delay by CMF (three cycles). No differences were seen in DFS or OS among the three groups.[Level of evidence: 1iiA] This study has also shown no difference in survival rates between four cycles of AC and six cycles of CMF.
The results of these various studies comparing and combining CMF and anthracycline-containing regimens suggest a slight advantage for the anthracycline regimens in both premenopausal and postmenopausal patients. Uncertainty remains, however, about whether there is an advantage to combining both regimens.
Evidence suggests that particular tumor characteristics may predict anthracycline-responsiveness. Data from retrospective analyses of randomized clinical trials suggest that, in patients with node-positive breast cancer, the benefit from standard-dose versus lower-dose adjuvant CAF, or the addition of doxorubicin to the adjuvant regimen, is restricted to those patients whose tumors overexpress HER2/neu.[Level of evidence: 1iiA] A retrospective analysis of the HER2/neu status of 710 premenopausal, node-positive women was undertaken to see the effects of adjuvant chemotherapy with CMF or cyclophosphamide, epirubicin, and fluorouracil (CEF).[Level of evidence: 2A] HER2/neu was measured using fluorescence in situ hybridization, polymerase chain reaction, and immunohistochemical methods. The study confirmed previous data indicating that the amplification of HER2/neu was associated with a decrease in RFS and OS. In patients with HER2/neu amplification, the RFS and OS were increased by CEF. In the absence of HER2/neu amplification, CEF and CMF were similar to RFS (HR for relapse, 0.91; 95% CI, 0.71–1.18; P = .049) and OS (HR for death, 1.06; 95% CI, 0.83–1.44; P = .68). Similar results were seen in a meta-analysis that included 5,354 patients in whom HER2 status was known from eight randomized trials (including the one just described) comparing anthracycline-containing regimens with non–anthracycline-containing regimens.