Locoregional Recurrence and Survival Outcomes by Type of Local Therapy and Trastuzumab Use Among Women with Node-Negative, HER2-Positive Breast Cancer

• Published in: Annals of surgical oncology Vol. 21; no. 11; pp. 3490 - 3496
• Main Authors: Peterson, David J., Truong, Pauline T., Sadek, Betro T., Alexander, Cheryl S., Wiksyk, Bradley, Shenouda, Mina, Raad, Rita Abi, Taghian, Alphonse G.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2014; Springer Nature B.V
• Subjects: Antibodies, Monoclonal, Humanized - therapeutic use; Antineoplastic Agents - therapeutic use; Breast Neoplasms - metabolism; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast Neoplasms - therapy; Breast Oncology; Combined Modality Therapy; Female; Follow-Up Studies; Humans; Immunoenzyme Techniques; Lymph Nodes - pathology; Mastectomy; Mastectomy, Segmental; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Grading; Neoplasm Recurrence, Local - metabolism; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - pathology; Neoplasm Recurrence, Local - therapy; Neoplasm Staging; Oncology; Prognosis; Receptor, ErbB-2 - metabolism; Receptors, Estrogen - metabolism; Receptors, Progesterone - metabolism; Retrospective Studies; Surgery; Surgical Oncology; Survival Rate; Trastuzumab; Locoregional Control; Breast Cancer; Overall Survival; Breast Cancer Specific Survival; Trastuzumab
• DOI: 10.1245/s10434-014-3767-6
• ISSN: 1068-9265

Background While human epidermal growth factor receptor 2 (HER2) overexpression is an adverse breast cancer prognostic factor, it is unclear whether there are differences in outcomes between types of local treatment in this population. This retrospective study examined locoregional recurrence and survival in women with node-negative, HER2+ breast cancer treated with breast-conserving therapy (BCT) versus mastectomy. Methods Subjects were 748 patients with pT1–2, N0, M0 HER2+ breast cancer, treated with BCT ( n  = 422) or mastectomy ( n  = 326). Trastuzumab was used in 54 % of subjects. The 5-year Kaplan–Meier locoregional recurrence free survival (LRRFS), breast cancer specific survival (BCSS), and overall survival (OS) were compared between cohorts treated with BCT versus mastectomy. Subgroup analyses of LRR and survival were performed separately among patients treated with BCT or mastectomy to examine the effect of trastuzumab on outcomes in each group. Results Median follow-up was 4.4 years. Patients treated with mastectomy had higher proportions of grade 3 histology (69 vs 60 %, p  = 0.004) and lower rates of hormone therapy (51 vs 64 %, p  < 0.001) and trastuzumab therapy (50 vs 57 %, p  = 0.04). The 5-year outcomes in women treated with BCT compared with mastectomy were: LRRFS 98.0 versus 98.3 % ( p  = 0.88), BCSS 97.2 versus 96.1 % ( p  = 0.70), and OS 95.5 versus 93.4 % ( p  = 0.19). Trastuzumab was associated with similar LRRFS and improved OS in both local treatment groups. Conclusions BCT is safe in the population of women with pT1–2, N0, HER2+ breast cancer, providing high rates of locoregional control and survival equivalent to mastectomy. Trastuzumab was associated with improved survival in both groups.