Other trials have clearly escalated doses beyond the standard range. The NSABP-B-22 and NSABP-B-25 trials, for example, escalated the dose of cyclophosphamide to 1,200 mg/m2 (without granulocyte-colony stimulating factor [G-CSF]) and 2,400 mg/m2 (with G-CSF), respectively, with no significant advantage observed in DFS or OS compared with the standard dose of 600 mg/m2.[172,173][Level of evidence: 1iiA]
A U.S. Intergroup study (CLB-9344) randomly assigned women with node-positive tumors to three dose levels of doxorubicin (60, 75, and 90 mg/m2). Following treatment with doxorubicin, a second randomization occurred to paclitaxel or to no further therapy. After chemotherapy, patients with ER-positive tumors were offered a planned course of tamoxifen for 5 years. No difference in DFS related to the dose of doxorubicin was found. In contrast, a Canadian trial (CAN-NCIC-MA5) in which cyclophosphamide, epirubicin, and 5-FU (CEF) were given to a total dose of 720 mg/m2 for a period of six 4-week cycles demonstrated at a median follow-up of 10 years for live patients, a 10-year RFS of 52% for patients who received CEF compared with 45% for CMF patients (HR for CMF vs. CEF = 1.31; stratified log-rank, P = .007). The 10-year OS for patients who received CEF and CMF was 62% and 58%, respectively (HR for CMF vs. CEF = 1.18; stratified log-rank, P = .085). The rates of acute leukemia have not changed since the original report, whereas the rates of congestive heart failure were slightly higher (four patients [1.1%] in the CEF group vs. one patient [0.3%] in the CMF group).[Level of evidence: 1iiA] The design of the trial does not allow a determination of whether anthracycline or dose-intensity or both is responsible for the improved outcome. A French trial showed that higher doses of epirubicin led to a high survival rate in women with poor-prognosis disease. A randomized trial that increased duration of epirubicin did not lead to increased survival at 10 years in node-positive premenopausal women.
A U.S. Intergroup trial (CLB-9741) compared, in a 2 � 2 factorial design, the use of adriamycin, cyclophosphamide, and paclitaxel concurrently (adriamycin and cyclophosphamide followed by paclitaxel) versus sequentially (adriamycin followed by paclitaxel followed by cyclophosphamide), given every 3 weeks or every 2 weeks with filgrastim, in 2,005 node-positive premenopausal and postmenopausal patients. At a median follow-up of 68 months, dose-dense treatment improved the primary end point, DFS in all patient population (HR = 0.80; P =.018) but not OS (HR = 0.85; P =.12). There was no interaction between density and sequence. Severe neutropenia was less frequent in patients who received the dose-dense regimens.[178,179] Grade 2 anemia (hemoglobin <10g/dL) was more frequent in the adriamycin and cyclophosphamide followed by paclitaxel every 2 weeks' arm (P < .001). At cycle five, this same arm had the lowest nadir hemoglobin of 10.7 g/dL, 0.9 g/dL lower than the other arms. Also, epoetin alpha use was highest in this arm compared with the three other arms (P = .013). In conclusion, dose-dense adriamycin and cyclophosphamide followed by paclitaxel every 14 days in C2 was associated with a greater incidence of moderate anemia, higher use of epoetin alpha, and more red cell transfusions than the other arms.[Level of evidence: 1iiA]