Royce, Melanie

526 Background: Z1041 randomized women with HER2+ operable breast cancer to: FEC → P+T (Arm 1) or P+T → FEC+T (Arm 2). Treatment administered as 5-FU 500 mg/m2, epirubicin 75 mg/m2 and cyclophosphamide 500 mg/m2 day 1 of a 21-day cycle x 4; paclitaxel 80 mg/m2weekly x 12 and T 4 mg/kg once then 2 mg/kg weekly x 11. T was to continue q3 weeks post-op for 40 weeks. A secondary aim was to examine the cardiotoxicity (CE). Methods: Ejection fraction (EF) was measured at baseline (BL), between regimens (wk 12), prior to surgery (wk 24) and PRN. Eligibility: BL EF ≥ 55%. CEs included decline in EF of > 15%, or >10% points to a value < LLN. Reversibility was adjudicated by blinded investigators as reversible (R: recovery of EF to ≤ 5% below BL), partially reversible (PR: recovery of > 10% points from nadir, but ≤ 5% points below BL), indeterminate (IN: no additional EF data), or irreversible (IRR:follow-up EF studies showed no improvement). Results: Of the 280 patients (Arm 1: 138) who began treatment, 15 pts (Arm 1: 10; Arm 2: 5) did not receive T. The number of weeks of T was 13 (range: 1-18) in Arm 1 and 24 (range: 1-31) in Arm 2. Changes in EF and severe treatment related cardiac toxicities prior to surgery (sx) are tabled below. There were 271 pts (Arm 1: 131) who had post-BL EFs. Prior to sx, there were 11 CE (8.3%) in Arm 1 and 13 CE (9.2%) in Arm 2. CEs were R in 12 pts (Arm 1: 5; Arm 2: 7); PR in 6 pts (Arm 1: 4; Arm 2: 2); IN in 4 pts (Arm 1: 2; Arm 2: 3) and IRR in 1 Arm 2 pt. Conclusions: The number of CE events in arms 1 and 2 showed no significant difference; greater scatter was observed in arm 2 patients. While concern for late cardiac events makes ongoing cardiac surveillance prudent due to A, concomitant use of A and T appear to not be associated with increased cardiac risk. Clinical trial information: NCT00513292. [Table: see text]

502 Background: Neoadjuvant chemotherapy (NAC) and concomitant trastuzumab (T) have produced high pathologic complete response (pCR) rates in HER2+ breast cancers. Z1041 addresses the timing of initiation of T with NAC. Methods: Women with operable HER2+ invasive breast cancer were randomized 1:1 to: FEC → P+T (Arm 1) or P+T → FEC+T (Arm 2) where treatment was administered as 5-FU 500 mg/m2, epirubicin 75 mg/m2 and cyclophosphamide 500 mg/m2 day 1 of a 21-day cycle x 4 (FEC); paclitaxel 80 mg/m2 weekly x 12 and trastuzumab 4 mg/kg once then 2 mg/kg weekly x 11. Eligibility also included: tumor > 2 cm or a positive lymph node and left ventricular ejection fraction > 55%. The primary aim was to compare the pCR rates in the breast (pBCR) between the regimens. Secondary endpoints were pCR rate in the breast and lymph nodes (pBNCR) and safety profile. All pts who began study treatment were included in the analyses. With 128 pts per regimen, a two-sided alpha=0.05 test of proportions would have a 90% chance of detecting a difference of 20% or more in the pBCR rates, when the pBCR rate with the poorer regimen is ≤ 25%. Results: From September 15, 2007 to December 15, 2011, 282 women (Arm 1: 140 pts) were enrolled. Two pts (Arm 1) withdrew without receiving treatment. The two arms were similar in age, stage, and hormone receptor (HR) status (HR neg: 40%). The severe (grade 3+) treatment-related toxicities included: neutropenia (Arm 1: 24.6%; Arm 2: 32.4%), fatigue (Arm 1: 4.3%; Arm 2: 8.5%), and neurosensory problems (Arm 1: 3.6%; Arm 2: 4.9%). The pBCR rate and pBNCR rates (Table) were not found to differ between the two regimens (Fisher’s exact p values: 0.905 and 0.811, respectively). Conclusions: High pCR rates can be achieved with trastuzumab in combination with anthracyclines and taxanes. The pBCR or pBNCR was not different between regimens based on the timing of initiation of trastuzumab. Clinical trial information: NCT00513292. [Table: see text]

LBA537 Background: Between 10-1-02 and 12-01-05, SWOG 0012 accrued patients to a two-arm randomized trial, with formal participation from NCCTG and CTSU participation by other cooperative groups. Arm 1 gave A at 60 mg/m2 and C at 600 mg/m2 q 3 wk IV for 5 cycles, arm 2 A at 24 mg/m2/wk × 15 IV and C at 60 mg/m2/day PO for 15 wk with G at 5 mcg/kg/day × 6/7 weekly. Both groups then received T at 80 mg/m2/wk × 12, and proceeded to surgery with pCR by NSABP criteria at the primary site as the endpoint. A total of 372 were randomized, and we report here on 265 patients (pts) evaluable for outcome, including those who did not proceed to surgery. In arm 1, pCR was seen in 17% vs 27% in arm 2 (p = .06); when adjusted for hormone receptor status (ER-PR- in 49% on arm 1, 41% on arm 2) and disease type (locally advanced vs inflammatory), the odds ratio in favor of arm 2 is 1.98 (95% CI 1.05–3.74, p = .034). For ER- PR- pts, pCR rates for Arm 1 vs 2 were 26 vs 43%, while for those with ER or PR+, pCR rates were 9 vs 14%. Inflammatory pts showed a striking difference in pCR rates for arm 1 vs arm 2 (12 vs 33%, p = .033). HER 2 status (+ in 29%) did not predict response or interact with treatment. Grade 3/4 toxicities (arm 1 vs 2, %) were as follows: hand-foot syndrome (0 vs 13), neutropenia (47 vs 16), neutropenic infection (1.8 vs 0.6), stomatitis (2 vs 11), and nausea/vomiting (11 vs 5). Toxicity from T was grade 3 neuropathy in 10%, with grade 3 or 4 neutropenia in 12%. There were no treatment-related deaths. Continuous or “metronomic” chemotherapy with AC is superior to standard intermittent AC, and the pCR rate reported for the continuous arm is the highest reported in a cooperative group experience for this patient population. [Table: see text]

Purpose Patients with inflammatory breast cancer (IBC) or locally advanced breast cancer (LABC) were randomly assigned to 21-day doxorubicin and cyclophosphamide administered for five cycles (standard arm) versus weekly doxorubicin and daily oral cyclophosphamide administered with granulocyte colony-stimulating factor support for 15 weeks (continuous arm). All patients had subsequent weekly paclitaxel for 12 weeks before surgery. Patients and Methods Patients (n = 372) were randomly assigned to the standard arm (n = 186) or the continuous arm (n = 186) stratified by disease type (LABC, n = 256; IBC, n = 116). The primary outcome was microscopic pathologic complete response (pCR) at surgery. Secondary outcomes included disease-free survival, overall survival, and toxicity. Results More patients in the standard arm had grade 3 to 4 leukopenia and neutropenia, but there were more instances of stomatitis/pharyngitis and hand-foot skin reaction in the continuous arm. Assessed among 356 eligible patients, pCR was not different between the treatment groups stratified by disease type (P = .42). In subset analysis, higher pCR rates were observed in the continuous arm versus the standard arm only for stage IIIB disease (P = .0057) and in IBC (P = .06). Comparison of overall survival and disease-free survival showed no difference between treatment groups (P = .37 and P = .87, respectively). Conclusion No significant clinical benefit was seen for the investigational arm in this trial overall.