Different responses to preoperative chemotherapy for invasive lobular and invasive ductal breast carcinoma

Pathologic Features of Breast Cancer Associated With Complete Response to Neoadjuvant Chemotherapy

Breast cancer patients with a complete pathologic response after neoadjuvant chemotherapy have a better prognosis than incomplete responders. The predictive value of the histologic characteristics of the tumor prior to neoadjuvant treatment has not been well defined, and there are no guidelines for reporting tumor characteristics in the core biopsy report. Histologic and nuclear grades, presence of tumor necrosis and angiolymphatic invasion (ALI), and estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression were assessed in core biopsies of 55 patients with invasive carcinomas. Patients were then uniformly treated with four cycles of doxorubicin/docetaxel followed by excisions and lymph node dissections. Complete pathologic response (pCR) was defined as having no invasive carcinoma at excision. Noncomplete pathologic response was defined as having invasive carcinoma at excision. Five of the 55 patients (9%) achieved pCR. Of the 5 complete responders, 4 (80%) had tumor necrosis in the core biopsy specimens, while only 8 of the 46 (17%) noncomplete responders (pNR) had this feature (P = 0.0086). Higher histologic and nuclear grades, ER, PR status, and HER-2/neu overexpression were not associated with pCR. The presence of ALI in the core biopsy, post-therapy excision, or both was associated with axillary lymph node metastases (P = 0.0062, P = 0.0249, and P = 0.0021, respectively). Although preliminary, our study suggests that the presence of tumor necrosis and ALI in the core biopsy may be important features to be included in the standard report.

Invasive Lobular Carcinoma Classic Type: Response to Primary Chemotherapy and Survival Outcomes

Purpose

To investigate the impact of histologic type invasive lobular carcinoma (ILC) versus invasive ductal carcinoma (IDC) on response to primary chemotherapy (PC) and long-term outcome.

Patients and Methods

The study included 1,034 patients with stage II and III breast cancer who participated in six clinical trials of PC at our institution between 1985 and 2002. One hundred twenty-two patients (12%) had ILC and 912 (88%) had IDC. All patients received anthracycline-based PC, and 346 patients (33.5%) also received a taxane as part of PC. Pathologic complete response (pCR) was defined as no evidence of invasive disease in the breast and axillary lymph nodes.

Results

The median patient age was 48 years (range, 18 to 79 years). Patients with ILC tended to be older (median age, 53 years v 47 years for patients with IDC) and have more hormone-receptor–positive tumors (92% v 62%; P < .001), lower nuclear grade (nuclear grade 3, 16% v 56%; P < .001), and higher stage at diagnosis (10% v 0% with stage IIIB or IIIC disease; P < .001). Patients with ILC were less likely to have a pCR (3% v 15%; P < .001) and had a larger number of involved axillary lymph nodes (41% v 26% had > 3 involved nodes; P = .001). At a median follow-up time of 70 months, ILC patients tended to have longer recurrence-free survival (P = .004) and overall survival (P = .001).

Conclusion

ILC is characterized by lower rates of pathologic response to PC but better long-term outcomes compared to IDC. pCR might not be a prognostic indicator for this group of patients.