Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. PALOMA-2 demonstrated statistically and clinically significant improvement in progression-free survival with palbociclib plus letrozole versus placebo plus letrozole in estrogen receptor–positive/human epidermal growth factor receptor 2–negative (ER+/HER2–) advanced breast cancer (ABC). Here, we report results for the secondary end point overall survival (OS). Postmenopausal women (N = 666) with ER+/HER2– ABC without previous systemic therapy for ABC were randomly assigned 2:1 to palbociclib plus letrozole or placebo plus letrozole. After a median follow-up of 90.1 months, 405 deaths were observed and 155 patients were known to be alive. The median OS was 53.9 months (95% CI, 49.8 to 60.8) with palbociclib plus letrozole versus 51.2 months (95% CI, 43.7 to 58.9) with placebo plus letrozole (hazard ratio [HR], 0.96 [95% CI, 0.78 to 1.18]; stratified one-sided P = .34). An imbalance in the number of patients with unknown survival outcome between the treatment arms (13.3% v 21.2%, respectively) limited interpretation of OS results. With recovered survival data, the median OS was 53.8 (95% CI, 49.8 to 59.2) versus 49.8 months (95% CI, 42.3 to 56.4), respectively (HR, 0.92 [95% CI, 0.76 to 1.12]; one-sided P = .21). OS was not significantly improved with palbociclib plus letrozole compared with placebo plus letrozole.

Purpose: The efficacy of lapatinib versus trastuzumab combined with taxanes in the first-line setting of human epidermal growth factor receptor 2 (HER2) –positive metastatic breast cancer (BC) is unknown. Patients and Methods: The MA.31 trial compared a combination of first-line anti-HER2 therapy (lapatinib or trastuzumab) and taxane therapy for 24 weeks, followed by the same anti-HER2 monotherapy until progression. Stratification was by prior (neo)adjuvant anti-HER2 therapy, prior (neo)adjuvant taxane, planned taxane, and liver metastases. The primary end point was intention-to-treat (ITT) progression-free survival (PFS), defined as time from random assignment to progression by RECIST (version 1.0) criteria, or death for patients with locally assessed HER2-positive tumors. The primary test statistic was a stratified log-rank test for noninferiority. PFS was also assessed for patients with centrally confirmed HER2-positive tumors. Results: From July 17, 2008, to December 1, 2011, 652 patients were accrued from 21 countries, resulting in 537 patients with centrally confirmed HER2-positive tumors. Median follow-up was 21.5 months. Median ITT PFS was 9.0 months with lapatinib and 11.3 months with trastuzumab. By ITT analysis, PFS was inferior for lapatinib compared with trastuzumab, with a stratified hazard ratio (HR) of 1.37 (95% CI, 1.13 to 1.65; P = .001). In patients with centrally confirmed HER2-positive tumors, median PFS was 9.1 months with lapatinib and 13.6 months with trastuzumab (HR, 1.48; 95% CI, 1.20 to 1.83; P < .001). More grade 3 or 4 diarrhea and rash were observed with lapatinib (P < .001). PFS results were supported by the secondary end point of overall survival, with an ITT HR of 1.28 (95% CI, 0.95 to 1.72; P = .11); in patients with centrally confirmed HER2-positive tumors, the HR was 1.47 (95% CI, 1.03 to 2.09; P = .03). Conclusion: As first-line therapy for HER2-positive metastatic BC, lapatinib combined with taxane was associated with shorter PFS and more toxicity compared with trastuzumab combined with taxane.

Purpose To determine whether the patterns of relapse according to estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status changed in the contemporary era. Patients and Methods Female patients referred to the British Columbia Cancer Agency with biopsy-proven stage I to III breast cancer (BC), diagnosed between 1986 and 1992 (cohort 1 [C1]) and between mid-2004 and 2008 (cohort 2 [C2]), and with known ER and HER2 status were eligible. Data were prospectively collected. C2 patients were matched to C1 patients for stage, grade, and ER and HER2 status. The primary end point was hazard rate of relapse (HRR) for BC by study cohort according to biomarker status. Secondary outcomes included HRR according to stage, grade, and age and hazard rate of death (HRD). Results After matching, 7,178 patients were included (3,589 patients in each cohort). BC subtype distribution was as following ER positive/HER2 negative, 70.8%; ER positive/HER2 positive, 6.9%; ER negative/HER2 positive, 6.6%; and ER negative/HER2 negative, 15.8%. For the overall population, the HRR approximately halved in all yearly intervals to year 9 in C2 compared with C1. Differences in HRR between cohorts were greater in the initial five intervals for HER2-positive and ER-negative/HER2-negative BC. The HRR decreased in C2 compared with C1 for all disease stages and grades. The HRD in C2 also decreased compared with C1, although to a lesser extent. Conclusion Although the pattern of relapse remains similar, there has been a significant improvement in BC relapse-free survival. Outcomes have improved for all BC subtypes, especially HER2-positive and ER-negative/HER2-negative BC, with the early spike in disease recurrence markedly decreased. These contemporary hazard rates are important for treatment decisions, patient discussions, and planning clinical trials of early BC.