A phase II study of metronomic paclitaxel/cyclophosphamide/capecitabine followed by 5-fluorouracil/epirubicin/cyclophosphamide as preoperative chemotherapy for triple-negative or low hormone receptor expressing/HER2-negative primary breast cancer

PURPOSE

Better treatments for triple-negative breast cancer (TNBC) are needed. To address this need, we studied the effects of preoperative metronomic paclitaxel/cyclophosphamide/capecitabine (mPCX) followed by 5-fluorouracil (FU)/epirubicin/cyclophosphamide (FEC) as preoperative chemotherapy in TNBC patients.

METHODS

Forty primary TNBC patients received four cycles of metronomic paclitaxel (80 mg/m(2) on Days 1, 8, and 15), cyclophosphamide (50 mg/body daily), and capecitabine (1,200 mg/m(2) daily), followed by four cycles of 5-FU (500 mg/m(2)), epirubicin (100 mg/m(2)), and cyclophosphamide (500 mg/m(2)) every 3 weeks. The primary end point was the pathological complete response (pCR) rate.

RESULTS

Forty patients formed the intent-to-treat population. The median dose intensities of paclitaxel, cyclophosphamide, and capecitabine were 89.7, 92.1, and 89.8%, respectively. Five patients discontinued mPCX and two discontinued FEC, primarily because of adverse events, resulting in a per-protocol population (PPS) of 33 patients. The pCR (ypT0/Tis ypN0) rate was 47.5% (19/40) in the intent-to-treat population and 54.5% (18/33) in the PPS. The clinical response rates were 36/40 (90.0%) and 31/33 (93.9%) in the intent-to-treat and PPS, respectively. The breast conservation rate was 72.7% (24/33), and 5/13 patients underwent partial resection instead of pre-planned total mastectomy. Grade 3-4 adverse events included neutropenia (35%), leukopenia (25%), and hand-foot syndrome (8%).

CONCLUSIONS

Metronomic PCX followed by FEC chemotherapy was associated with a high pCR rate and low toxicity in TNBC patients. Further studies of this regimen in larger numbers of patients are warranted.

A GINECO randomized phase II trial of two capecitabine and weekly paclitaxel schedules in metastatic breast cancer

To determine whether capecitabine schedule adaptation improves the tolerability of capecitabine-paclitaxel combination therapy for metastatic breast cancer (MBC), patients with anthracycline-pretreated HER2-negative MBC were randomized to either arm A (21-day cycles: capecitabine 1,000 mg/m(2) twice daily, days 1-14; paclitaxel 60 mg/m(2), days 1, 8, and 15) or arm B (28-day cycles: capecitabine 1,000 mg/m(2) twice daily, days 1-5, 8-12, and 15-19; paclitaxel 80 mg/m(2), days 1, 8, and 15). The primary endpoint was the incidence of dose reductions or delays >1 week for grade 3/4 toxicity. Secondary endpoints were efficacy and safety. All 130 randomized patients were evaluable for safety. Dose reduction or delay for grade 3/4 toxicity occurred in 39% of patients in arm A and 34% in arm B during cycles 1-6. In arm A, there were significantly more toxicity-related dose reductions (cycles 1-6: 82 vs. 67%, respectively; P = 0.05) and discontinuations (29 vs. 8%, respectively). Grade 3 diarrhea occurred in 12 and 0%, respectively, and grade 3 hand-foot syndrome in 12 versus 9%, respectively (grade 4 not applicable). There were no detectable differences in efficacy. Weekday capecitabine dosing with weekly paclitaxel may improve tolerability without a detrimental effect on efficacy, and merits further evaluation in patients suited to combination chemotherapy.

Capecitabine and paclitaxel combination chemotherapy for inoperable or recurrent breast cancer: a phase I dose-finding study by the Kinki Breast Cancer Study Group

BACKGROUND

The combination of capecitabine and paclitaxel (XP) has demonstrated synergistic antitumor activity in preclinical models. Three-weekly XP regimens have demonstrated excellent efficacy in phase II and III trials in metastatic breast cancer. We conducted a dose-finding study to identify the recommended 4-weekly XP regimen in patients with inoperable or recurrent breast cancer for phase II evaluation.

METHODS

Eligible patients had inoperable or recurrent breast cancer previously treated with chemotherapy (but not capecitabine or paclitaxel) in the (neo)adjuvant or metastatic setting. Each 4-week treatment cycle consisted of escalating doses of capecitabine (628 or 829 mg/m(2) twice daily [b.i.d.] on days 1-21) and paclitaxel (80 or 90 mg/m(2) on days 1, 8, and 15). Dose-limiting toxicities (DLT) were evaluated during the first two cycles.

RESULTS

Nine patients were treated. At dose level 1 (capecitabine 628 mg/m(2) b.i.d. plus paclitaxel 80 mg/m(2)), one patient experienced a DLT (grade 3 non-hematologic toxicity). There were no further DLTs at dose level 1 or 2. Although the MTD was not reached, dose level 2 (capecitabine 829 mg/m(2) b.i.d., days 1-21, plus paclitaxel 80 mg/m(2), days 1, 8, and 15, every 28 days) is recommended for phase II evaluation, taking into consideration the single-agent doses used in Japan and the doses identified in Western studies of 3-weekly XP. The overall response rate was 44%; all patients treated at dose level 2 achieved a partial response.

CONCLUSIONS

This 4-weekly XP regimen was well tolerated, active in patients with pretreated advanced breast cancer, and could be given as outpatient treatment. These results are consistent with findings of phase II and III trials evaluating 3-weekly regimens, and indicate that further investigation of a 4-weekly XP regimen is warranted.