Prognostic significance of Substance P/ Neurokinin 1 receptor and its association with hormonal receptors in breast carcinoma

To evaluate the expression and Immunolocalization of Substance P (SP)/ Neurokinin-1 Receptor (NK-1R) in Breast Carcinoma (BC) patients and its association with routine proliferative markers (ER, PR, HER2/ neu and Ki-67). MethodsA cross-sectional study was performed on 34 cases of BC. There were 23 cases of group A (Grade III), 8 of group B (Grade II) and only 3 cases of group C (Grade I). Age range comprised of patients from 20-80 years and the mean age of patients was 45.74 years. HE, ER, PR, HER2 and Ki-67 staining was performed as routine biomarkers. Samples were then processed for immunomarkers study of Substance P and NK-1R immunohistochemistry was performed for few cases. Results14/23 cases (61%) of group A, 7/8 cases (88%) of group B and 2/3 (67%) cases of group C were SP positive. Overall, strong staining ([≥] 10% tumors cells), labeled as "3+", was observed in 9/14 (64.2%) cases of group A and 1/8 (12.5%) case of group B. Moderate staining labelled as "2+" (in [≥] 10% tumor cells) was observed in 3/14 (21.4%) cases of group A, 4/8 (50%) cases of group B. weak positive staining "1+" was observed in only 2/14 (14.28%) cases of group A, 2/8 (25%) cases of group B and all 2/2 (100%) cases of group C. ConclusionsSP and NK-1R is overexpressed in breast carcinomas and there is significant association between grade of tumor and their overexpression. It may serve as a novel biomarker for grading of BC. We also suggest that NK-1R antagonists as a potential therapeutic strategy to inhibit and manage BC. Key PointsO_LIImmunohistochemical expression of Substance P and Neurokinin 1 Receptor in breast carcinoma tissue was evaluated C_LIO_LIIt was strongly expressed in grade III, with maximum intensity C_LIO_LIIt may be investigated further for its role as prognostic and diagnostic marker C_LIO_LITherapeutic potential of Neurokinin-1 Receptor antagonists must be explored C_LI