Perez, Edith A.

Abstract Background: We have previously shown in a phase III neoadjuvant trial that early development of lapatinib-induced rash (i.e. within 6 weeks after lapatinib initiation) is independently associated with a higher chance of obtaining a pathological complete response (Azim et al; JCO 2013). In the current study, we aimed to investigate whether early lapatinib-induced rash is associated with improved survival in the context of a large phase III adjuvant trial. Methods: This analysis is based on the ALTTO trial (BIG 2-06, Alliance N063D), in which patients with HER2-positive early breast cancer were randomized to adjuvant trastuzumab, lapatinib, their sequence or their combination for a total duration of 1 year. In this sub-study, we evaluated whether the development of rash (any grade) within 6 weeks of lapatinib initiation was associated with disease-free (DFS) and overall survival (OS). All analyses were tested in a multivariate model adjusted for treatment arm, treatment completion and trial stratification factors. Results: A total of 6,098 lapatinib-treated patients were included in the current analysis; of whom 2,006 patients (32.9%) developed early lapatinib-induced rash, 1,025 (16.8%) developed rash after 6 weeks and 3,067 (50.3%) did not develop rash. No differences in patient characteristics were observed between the three groups apart from a higher frequency of younger patients (≤ 50) in the early rash group (54% vs. 47% and 44%, p<0.0001). At a median follow-up of 4.5 years, 876 (14.37%) and 377 (6.18%) patients in the lapatinib containing arms experienced a DFS and OS event, respectively. In a multivariate analysis confined to patients randomized to the lapatinib containing arms, the development of early rash was associated with improved DFS (HR: 0.80; 95%CI: 0.69-0.93, p=0.004) and OS (HR: 0.61; 95%CI: 0.48 - 0.78, p<0.001) compared to patients who did not develop early rash, with no interaction according to patient's age (p=0.9). No significant association was observed between the development of rash after 6 weeks of lapatinib initiation and survival. Compared to patients randomized to the trastuzumab alone arm (n=2,076), patients who developed early rash in the sequence (n=580) or combination (n=704) arms of trastuzumab/lapatinib had superior DFS (Sequence: HR 0.75 [95% CI: 0.58 – 0.98], p=0.034; Combination: HR 0.69 [95% CI: 0.54 – 0.89], p=0.005) and OS (Sequence: HR 0.57 [95%CI: 0.36 – 0.88], p=0.012; Combination: HR 0.59 [95% CI: 0.39 – 0.89], p=0.011). On the other hand, patients randomized to the lapatinib only arm who developed early rash (n=722) still had inferior DFS (HR 1.28 [95% CI: 1.04 – 1.59], p=0.02) with no difference in OS (HR: 0.95; 95%CI: 0.67 – 1.35, p=0.79) compared to patients randomized to the trastuzumab alone arm. Conclusions: The results support our previous findings in the neoadjuvant setting that early development of skin rash within the first 6 weeks can identify patients who derive superior benefit of lapatinib treatment. Citation Format: Azim Jr HA, Sonnenblick A, Agbor-Tarh D, Bradbury I, Daly F, Huang Y, Dueck AC, Pritchard K, Wolff AC, Jackisch C, Lang I, Untch M, Smith I, Boyle F, Xu B, Gomez H, Perez E, Piccart M, de Azambuja E. The impact of early lapatinib-induced rash on disease-free and overall survival in patients treated within the ALTTO phase III randomized trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD5-07.

Background Lapatinib (L) plus trastuzumab (T) improves outcomes for metastatic human epidermal growth factor 2–positive breast cancer and increases the pathologic complete response in the neoadjuvant setting, but their role as adjuvant therapy remains uncertain. Methods In the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization trial, patients with centrally confirmed human epidermal growth factor 2–positive early breast cancer were randomly assigned to 1 year of adjuvant therapy with T, L, their sequence (T→L), or their combination (L+T). The primary end point was disease-free survival (DFS), with 850 events required for 80% power to detect a hazard ratio (HR) of 0.8 for L+T versus T. Results Between June 2007 and July 2011, 8,381 patients were enrolled. In 2011, due to futility to demonstrate noninferiority of L versus T, the L arm was closed, and patients free of disease were offered adjuvant T. A protocol modification required P ≤ .025 for the two remaining pairwise comparisons. At a protocol-specified analysis with a median follow-up of 4.5 years, a 16% reduction in the DFS hazard rate was observed with L+T compared with T (555 DFS events; HR, 0.84; 97.5% CI, 0.70 to 1.02; P = .048), and a 4% reduction was observed with T→L compared with T (HR, 0.96; 97.5% CI, 0.80 to 1.15; P = .61). L-treated patients experienced more diarrhea, cutaneous rash, and hepatic toxicity compared with T-treated patients. The incidence of cardiac toxicity was low in all treatment arms. Conclusion Adjuvant treatment that includes L did not significantly improve DFS compared with T alone and added toxicity. One year of adjuvant T remains standard of care.

Purpose Significant improvement in survival outcomes has been established with the addition of trastuzumab to adjuvant chemotherapy for human epidermal growth factor receptor 2 (HER2) –positive early breast cancer treatment. However, trastuzumab may increase the risk of cardiac toxicity, and long-term evaluation of its incidence and risk factors are warranted. Methods NCCTG (Alliance) N9831 trial compared adjuvant doxorubicin and cyclophosphamide (AC) followed by either weekly paclitaxel (arm A); paclitaxel then trastuzumab (arm B); or paclitaxel plus trastuzumab followed by trastuzumab alone (arm C) in patients with HER2-positive breast cancer. Cumulative incidence of cardiac events (CE) and left ventricular ejection fraction (LVEF) were evaluated in 1,944 women who proceeded to post-AC therapy. Risk factors for trastuzumab-induced cardiac toxicity were identified by Cox regression models. Results The 6-year cumulative incidence of CE was 0.6% in arm A, 2.8% in arm B, and 3.4% in arm C. At a median follow-up of 9.2 years, only two additional CHF diagnoses (of 1,046 patients) occurred beyond our previously reported follow-up time of 3.75 years. LVEF recovered in the majority of the patients who developed CHF. There were two cardiac deaths in arm A and one each in arms B and C. Age of 60 years or older, registration LVEF less than 65%, and use of antihypertensive medications were associated with an increased risk of CE in arms B and C. Conclusion The cumulative incidence of CE at 6 years was slightly higher with the addition of trastuzumab; however, the late development of CE is infrequent. Trastuzumab (in the context of anthracycline- and taxane-based therapy) continues to have a favorable benefit-risk ratio.

Abstract Introduction: Invasive lobular carcinoma (ILC) comprises approximately ∼10-20% of breast cancers (BC) and appears to have a distinct biology from invasive ductal carcinoma (IDC). ILC is known to have a higher incidence of multifocal (MF) disease when compared to IDC (Biglia N, EJSO, 2013) and in general, MF BC has been associated with an increased rate of regional lymph node metastases (Cabioglu N, JACS, 2009). Treatment decisions are most often defined by the largest of the MF tumors without targeting potentially relevant biologic heterogeneity of the disease. We conducted a genomic analysis of MF ILC to help address this knowledge void. Methods: We characterized gene expression in multiple foci from 11 patients (pts) with MF ILC (all ER+ and HER2-, mean number of foci = 2.62) and 13 benign breast tissues. RNA was extracted from 3×1.5mm cores from each foci and gene expression was measured in 730 known cancer genes using the NanoString PanCancer pathways panel. Differential gene expression analyses were performed between 1) MF tumors and benign tissue (BT) accounting for pairing of pts and 2) different foci of MF tumors from the same ILC pt by ANOVA. The association of clinical covariates (age, number of tumors, grade and stage) in the top genes that were differentially expressed between multiple foci was assessed by linear mixed models accounting for pt and tumor. Results: A total of 20 genes (including MET and EGFR, top 5 genes: SPRY2, SOX17, FIGF, PDGFA, IL6) were differentially expressed (p<0.05) between malignant foci from the same pt, after correction by false discovery rate (FDR). EGFR expression was also negatively associated with the number of positive lymph nodes (N1a vs N0 absolute fold change = 0.51, p = 0.043). We observed an excess of genes that were down-regulated in MF ILC compared to BT. 277 genes were differentially expressed at p<0.05 after correction by FDR. The top 5 differentially expressed genes (by fold change) between ILC and BT were COL11A1, COL1A1, WIF1, FIGF and PROM1. CDH1, a known marker of ILC, was down-regulated in ILC compared to benign (absolute fold change = 2.54, p = 6.02×10−6), ranked only 39/277 genes by fold change. MET and EGFR ranked 29 and 42/277 genes (p = 5.99×10−9 and 3.32×10−8 respectively). Conclusion: We observed significant heterogeneity for 20/730 genes between individual foci of MF ILC within the same pt suggesting that MF synchronous ILC lesions may have different biologic behavior. This in turn may have important prognostic implications with potential therapeutic utility. Our analyses also shows significant down-regulation of gene expression between ILC tumors and BT for many genes other than CDH1 suggesting that additional biomarkers can be used to further characterize ILC Study funded in part by Mayo Clinic Cancer Focus Research Team, the 26.2 with Donna Foundation and the Serene M. and Frances C. Durling endowment. Citation Format: Pooja Advani, Nadine Norton, Daniel J. Serie, Xochiquetzal Geiger, Julia E. Crook, Aubrey E. Thompson, Edith A. Perez, Alvaro Moreno Aspitia. Characterization of individual foci of multifocal invasive lobular breast cancer using gene expression profiling. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4761. doi:10.1158/1538-7445.AM2015-4761

Purpose We compared efficacy of trastuzumab versus no trastuzumab in patients with small (≤ 2 cm) human epidermal growth factor receptor 2 (HER2) –positive breast cancer treated in randomized trials. Methods A meta-analysis was conducted using data from five of the six adjuvant trastuzumab trials. Efficacy end points were disease-free survival (DFS) and overall survival (OS). Separate analyses were prospectively planned for hormone receptor (HR) –positive and HR-negative cohorts. Random effect models and Yusuf-Peto fixed effects models assessed the impact of heterogeneity on baseline hazards and treatment effects across studies. Peto-Pike cumulative incidence estimates were stratified by study and nodal status. Results Median follow-up time was 8 years. For 2,263 patients with HR-positive disease, 8-year cumulative incidence rates comparing trastuzumab versus no trastuzumab were 17.3% versus 24.3% (P < .001) for DFS and 7.8% versus 11.6% (P = .005) for OS, respectively; for 1,092 HR-positive patients with zero or one positive lymph nodes, results were 12.7% versus 19.4% (P = .005) for DFS and 5.3% versus 7.4% (P = .12) for OS, respectively. For 1,957 patients with HR-negative disease, 8-year cumulative incidence rates were 24.0% versus 33.4% (P < .001) for DFS and 12.4% versus 21.2% (P < .001) for OS, respectively; for 1,040 HR-negative patients with zero or one positive lymph nodes, results were 20.4% versus 26.3% (P = .05) for DFS and 8.2% versus 12.2% (P = .084) for OS, respectively. Conclusion Women with HER2-positive tumors ≤ 2 cm in the randomized trastuzumab trials derived substantial DFS and OS benefit from adjuvant trastuzumab. Trastuzumab-treated patients with HR-positive disease and ≤ one positive lymph node may be candidates for trials assessing less aggressive treatment approaches.