Adjuvant trastuzumab with chemotherapy is effective in women with small, node‐negative, HER2‐positive breast cancer

Abstract

BACKGROUND: Several large, randomized trials established the benefits of adjuvant trastuzumab with chemotherapy. However, the benefit for women with small, node-negative HER2-positive (HER2þ) disease is unknown, as these patients were largely excluded from these trials. Therefore, a retrospective, single-institution, sequential cohort study of women with small, node-negative, HER2þ breast cancer who did or did not receive adjuvant trastuzumab was conducted. METHODS: Women with 2 cm, node-negative, HER2þ (immunohistochemistry 3þ or fluorescence in situ hybridization !2) breast cancer were identified through an institutional database. A ''no-trastuzumab'' cohort of 106 trastuzumab-untreated women diagnosed between January 1, 2002 and May 14, 2004 and a ''trastuzumab'' cohort of 155 trastuzumab-treated women diagnosed between May 16, 2005 and December 31, 2008 were described. Survival and recurrence outcomes were estimated by Kaplan-Meier methods. RESULTS: The cohorts were similar in age, median tumor size, histology, hormone receptor status, hormone therapy, and locoregional therapy. Chemotherapy was administered in 66% and 100% of the ''no trastuzumab'' and ''trastuzumab'' cohorts, respectively. The median recurrence-free and survival follow-up was: 6.5 years (0.7-8.5) and 6.8 years (0.7-8.5), respectively, for the ''no trastuzumab'' cohort and 3.0 years (0.5-5.2) and 3.0 years (0.6-5.2), respectively, for the ''trastuzumab'' cohort. The 3-year locoregional invasive recurrence-free, distant recurrence-free, invasive disease-free, and overall survival were 92% versus 98% (P ¼ .0137), 95% versus 100% (P ¼ .0072), 82% versus 97% (P < .0001), and 97% versus 99% (P ¼ .18) for the ''no trastuzumab'' and ''trastuzumab'' cohorts, respectively. CONCLUSIONS: Women with small, node-negative, HER2þ primary breast cancers likely derive significant benefit from adjuvant trastuzumab with chemotherapy. Cancer 2011;117:5461-

Brève de l’AERIO

“…Même si plusieurs séries rétrospectives [6,7] suggéraient un bénéfice à un traitement par chimiothérapie et trastuzumab pour les tumeurs pT1abN0 HER2+, le schéma optimal (efficace et le moins toxique) n'était pas défini. Cette étude montre un taux de rechute invasive ou de décès à trois ans de 1,3 % avec le schéma 12 injections de paclitaxel hebdomadaire et un an de trastuzumab, soit un taux nettement plus faible que dans toutes les données « historiques », et cela avec une très faible toxicité, notamment cardiaque.…”

Association of HER2 Overexpression and Prognosis in Small (T1N0) Primary Breast Cancers

“…This corroborates a recently published retrospective report into adjuvant trastuzumab therapy in women with HER2-positive T1N0 breast cancer, where 4-year recurrence and death rates were lower amongst those who received trastuzumab (n = 155) compared with those who did not receive trastuzumab (n = 106). The results were respectively: locoregional invasive recurrence-free survival event (1.3 vs. 7.5%); contralateral invasive recurrence-free survival event (0 vs. 1.9%); distant recurrence-free survival (0 vs. 5.7%); and death (0.7 vs. 2.8%) [14]. …”

Adjuvant regimens with trastuzumab administered for small HER2-positive breast cancer in routine clinical practice

“…Although these clinical trials mainly included patients with large tumors, data obtained from those trials that allowed the inclusion of patients with tumor sizes B2 cm also supported the benefit of adding trastuzumab to adjuvant treatments [8,9]. Furthermore, other observational studies focusing on patients with small HER2-positive breast cancers also supported such a benefit, as they reported significant improvements in terms of tumor recurrence and/ or patient survival after the administration of adjuvant trastuzumab [11][12][13][14].…”