[133] Classifications of Pathological Response and Long-Term Follow-Up in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy.

Adriana D Corben, Chy Teo, Rita AbiRaad, Alessandro Bombonati, Frederick C Koerner, Alphonse Taghian, Elena F Brachtel. Memorial Sloan-Kettering Cancer Center, New York, NY; Tan Tock Seng Hospital, Singapore, Singapore; Massachusetts General Hospital and Harvard Medical School, Boston

Background: Breast cancer, especially in locally advanced stages, is increasingly treated with neoadjuvant chemotherapy (NACT) to reduce local disease and to assess response to treatment. Chemotherapy can cause a spectrum of morphological alterations in tumors and lymph nodes. Various histopathological classification schemes are available to analyze the response. Our study compares practical application and predictive use of several of those schemes.
Design: Sixty-two patients were enrolled in a randomized phase II clinical trial for sequential NACT with doxorubicin and paclitaxel. Study pathologists reviewed H&E sections from patients' tumors sampled before (core biopsy) and after treatment (excision or mastectomy). Response was assessed following NSABP-B18 criteria, Miller-Payne grading system (MPG), Residual Disease in Breast and Nodes (RDBN, a derivative of the Modified Nottingham Prognostic Index), Sataloff tumor (T), Sataloff lymph nodes (N), and Residual Cancer Burden (RCB) as determined by web calculator. Results of the pathological classifications were correlated with disease-free survival (DFS) by Kaplan-Meier curves with mean (median) clinical follow-up of 80 (86) months.
Results: No patient with no residual invasive carcinoma after NACT relapsed (n=5), whereas 27% of all patients developed metastatic disease during follow-up. Lymph node status (N0,N1,N2,N3) correlated with DFS (p<0.0001), as did the four groups of RDBN (p=0.02). The Kaplan-Meier curves of other classifications indicated associations (RCB, Sataloff-N) or showed incongruent patterns (NSABP-B18, MPG, Sataloff-T). Post-chemotherapy histologic grade showed an association with DFS but the number of well-differentiated tumors (n=5) was too low for statistical analysis. We did not detect a correlation between age, menopause, chemotherapy sequence, tumor size, estrogen receptor or HER-2 status with DFS.
Conclusions: Pathological complete response indicates a favorable survival. This study shows that lymph node status and histologic grade are critical parameters for the long-term outcome after post-neoadjuvant chemotherapy. Classification schemes that strongly weigh lymph node involvement and tumor grade demonstrate better correlation with long-term outcome than those based only on tumor size or cellularity.
Category: Breast

Tuesday, March 1, 2011 11:15 AM

Platform Session: Section C, Tuesday Morning

 

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