Histological features of breast cancer, highly sensitive to chemotherapy

Background  To establish tailor-made therapy for breast cancer, we investigated the possibility of predicting chemotherapy sensitive cases based on pre-therapeutic histological features. as]Methods: A total of 87 breast cancer patients underwent neoadjuvant chemotherapy with a paclitaxel (80 mg/m²/qlw, 12 courses) or an epirubicin regimen (90 mg/m²/q3wks, 4 courses). We investigated the chemo-sensitivity of invasive ductal carcinoma, solid-tubular carcinoma consisting of highly malignant cancer cells with many mitoses. We refer to this type of carcinoma as“chemo-sensitive carcinoma”and compared the histological therapeutic effects of chemo-sensitive and chemo-insensitive carcinomas. Results  1) Out of 87 patients, 20 cases (23%) showed the histological features of chemo-sensitive carcinomas on pre-therapeutic needle biopsy specimens. The remaining 67 cases (77%) were classified as chemo-insensitive carcinoma. 2) Histologically marked or complete response were observed in 50% (10/20) of chemo-sensitive carcinomas and 10% (7/67) of chemo-insensitive carcinomas (x² = 15.33, P=0.0001). Multivariate analysis of chemo-sensitive carcinoma, including HER2, hormone receptor and p⁵³ status, revealed that chemo-sensitive carcinoma had a significant correlation with the histological therapeutic effects (P=0.01119). 3) Pathological complete response (pCR) was achieved in 35% (7/20) of chemo-sensitive carcinomas and 1.5% (1/67) of chemo-insensitive carcinomas (x²=20.71,P<0.0001). Multivariate analysis revealed that chemo-sensitive carcinoma had a significant correlation with pCR (p=0.0091) Conclusion  The histological features of chemo-sensitive carcinoma were significant predictive factors for chemotherapeutic efficacy.