Histopathologic changes following neoadjuvant chemotherapy in locally advanced breast cancer.

Aims: To compare the clinical and pathologic assessment of response to neoadjuvant chemotherapy and describe the various histopathologic changes observed. Materials and Methods: We studied a group of 40 patients with locally advanced breast cancer who had their initial workup in the form of clinico-imaging assessment of the size and pretreatment biopsy from the lesion. All the patients received two to six cycles of neoadjuvant chemotherapy, either cyclophosphamide 50 to 60 mg/m 2 IV, doxorubicin 40 to 50 mg/m 2 IV and 5-fluorouracil 500 to 800 mg/m 2 IV (CAF) or cyclophosphamide, epirubicin, and 5-fluorouracil (CEF). Clinical and pathologic assessment of response to chemotherapy was done based on the UICC guidelines. Result: Complete clinical response (cCR) was seen in 10% cases (4/40), thirty percent patients had (12/40) partial response and 60% (24/40) had stable disease after neoadjuvant chemotherapy. Pathologic complete response (pCR) with no evidence of viable tumor was observed in 20% patients (8/40). Fifteen patients (37.5%) showed partial response and 42.5% patients (17/40) had a stable disease. No patient progressed during the course of chemotherapy. Changes in the tumor type were observed following chemotherapy, most common being the mucinous change. Histologic changes like dyscohesion, shrinkage of tumor cells, elastosis, collagenization, necrosis, lymphocytic reaction, giant cell response are some of the common observations seen following treatment with neoadjuvant chemotherapy. Conclusion: Pathologic assessment of response to neoadjuvant chemotherapy is a better predictor than the clinical response. The chemotherapy drugs can be modified based on the response observed after 1-2 cycles of neoadjuvant, the response being based on both tumor and patient's responsiveness.

Pathological complete response in locally advanced breast cancer: Determinants and predictive significance.

Background. Neoadjuvant chemotherapy is now the standard approach for most large breast cancers including locally advanced cancers of the breast. The majority of patients respond satisfactorily to chemotherapy with effective downsizing of tumours to consider breast conservation surgery. Pathological complete response (pathCR) is known to be a strong predictor of good outcome; however, many factors are known to influence the extent of response to chemotherapy. It has been observed that smaller the tumour, better is the response achieved in contrast to larger and locally advanced tumours where only one-third may respond well enough to merit breast conservation. Various other clinical, biological and molecular factors are also being evaluated as effective predictors of chemosensitivity. Most of these are either not easily available for all patients in developing countries or are overtly expensive and not applicable for all patients. Methods. We evaluated the clinical and pathological predictors of response to chemotherapy in 1402 women with locally advanced breast cancer. Results. There was a higher rate of pathCR in smaller tumours, younger women and ER-negative as well as triple negative tumours. The presence of ductal carcinoma in situ (DCIS) and lymphatic and vascular invasion (LVI) were associated with lower pathCR. Conclusion. In the absence of ready availability of expensive molecular and genomic assays, clinical parameters and standard histopathological variables can also be useful indicators of response to neoadjuvant chemotherapy. Additionally, they can help identify those who could be eventually conserved or have a better outcome.