ROLE OF HORMONE RECEPTORS AND HER2 IMMUNOHISTOCHEMISTRY IN PREDICTING RESPONSE TONEOADJUVANT CHEMOTHERAPY IN BREAST CANCER

Abstract

Introduction:
In locally advanced breast cancers neoadjuvant chemotherapy is used to downstage the tumor
before surgery. Ability to predict those who would respond to neo-adjuvant chemotherapy would
be of great clinical use to maximize the treatment and minimize unnecessary toxicity and cost.
The objective of this study is to find out the relationship between the immunohistochemical
markers (ER, PR and Her2) in pretreatment trucut biopsy of breast cancer and the response to
neoadjuvant chemotherapy.
Methods:
Expression of ER, PR and Her2 were studied in the pretreatment trucut biopsies of 47 cases.
Trucut biopsies were graded according to Bloom Richardson grading and degree of fibrosis and
necrosis also assessed. These were correlated with the pathological response to neoadjuvant
chemotherapy in subsequent mastectomy specimens.
Results:
22 out of 47 cases demonstrated pathological complete response. The highest rate of pathological
response was found in grade 3 tumors (81.8% with a significant p value of 0.0127) and triple
negative tumors (65% with a significant p value of 0.0314). No statistically significant
correlation was found between presence of fibrosis and necrosis in the original tumor and
pathological response.
Conclusion:
Tumor grade and triple negativity in the trucut biopsies of breast cancer can predict the response
to neoadjuvant chemotherapy in breast cancer. Tumor grading and immunohistochemistry status
should be assessed in pretreatment trucut biopsy before selecting patients for neoadjuvant
chemotherapy.