Histological features of breast cancer, highly sensitive to chemotherapy

To establish tailor-made therapy for breast cancer, we investigated the possibility of predicting chemotherapy sensitive cases based on pre-therapeutic histological features.

A total of 87 breast cancer patients underwent neoadjuvant chemotherapy with a paclitaxel (80 mg/m(2)/q1w, 12 courses)or an epirubicin regimen (90 mg/m(2)/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.

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 (chi(2)=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 (chi(2)=20.71, p<0.0001). Multivariate analysis revealed that chemo-sensitive carcinoma had a significant correlation with pCR (p=0.0091).

The histological features of chemo-sensitive carcinoma were significant predictive factors for chemotherapeutic efficacy.