Pathological responses and survival of patients with human epidermal growth factor receptor 2-positive breast cancer who received neoadjuvant chemotherapy including trastuzumab

• Published in: Breast cancer (Tokyo, Japan) Vol. 21; no. 5; pp. 563 - 570
• Main Authors: Ohzawa, Hideyuki, Sakatani, Takashi, Niki, Toshiro, Yasuda, Yoshikazu, Hozumi, Yasuo
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01-09-2014; Springer
• Subjects: Adjuvant treatment; Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal, Humanized - administration & dosage; Antibodies, Monoclonal, Humanized - therapeutic use; Antimitotic agents; Antineoplastic agents; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Breast cancer; Breast Neoplasms - drug therapy; Breast Neoplasms - metabolism; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Cancer; Cancer patients; Cancer Research; Diagnosis; Epidermal growth factor; Estrogen; Female; Humans; Lymphatic Metastasis - pathology; Medicine; Medicine & Public Health; Middle Aged; Neoadjuvant Therapy; Oncology; Oncology, Experimental; Original Article; Patient outcomes; Progesterone; Receptor, ErbB-2 - metabolism; Retrospective Studies; Surgery; Surgical Oncology; Survival Analysis; Trastuzumab; Treatment Outcome; Neoadjuvant chemotherapy; Pathological complete response; Neoadjuvant response index; HER2; Trastuzumab
• ISSN: 1340-6868; 1880-4233
• DOI: 10.1007/s12282-012-0424-4

Background
The effectiveness of neoadjuvant chemotherapy is evaluated on the basis of pathological responses and survival outcome, because achievement of a pathological complete response (pCR) is a good predictor of long-term survival. However, few studies have assessed the survival of breast cancer patients who received neoadjuvant chemotherapy including trastuzumab.
Methods
The records of 161 breast cancer patients who received neoadjuvant chemotherapy between January 2006 and December 2011 were retrospectively reviewed. The patients were categorized into 4 subgroups on the basis of the status of the estrogen receptor (ER), the progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). HER2-positive patients received trastuzumab-based regimens. Pathological responses and survival were analyzed on the basis of breast cancer subtypes.
Results
The pCR results obtained were: luminal A and B (ER and/or PR-positive, HER2-negative), 6.3 % (5/79 cases); luminal–HER2 hybrid (ER and/or PR-positive, HER2-positive), 25.0 % (5/20 cases); HER2-enriched (ER and PR-negative, HER2-positive), 63.0 % (17/27 cases); and triple-negative (ER and PR-negative, HER2-negative), 25.7 % (9/35 cases). Achievement of pCR was a good predictor of disease-free survival in the HER2-enriched group. Overall survival of patients with pCR was slightly, but not significantly, better in the HER2-enriched and triple-negative subgroups.
Conclusion
Responses and survival after neoadjuvant chemotherapy including trastuzumab of patients with HER2-positive tumors differed among disease subtypes. Our findings suggest that disease subtype is an important determinant of the efficacy of neoadjuvant chemotherapy.