EGFR and HER-2/neu Expression in Gallbladder Carcinoma: An Institutional Experience

Gallbladder cancer (GBC) is the most common malignancy of the biliary tract in India. Despite the recent advancement in the understanding of the cancer biology, the disease still remains a therapeutic challenge with poor prognosis and low survival. Surgery is the primary modality of treatment and rest of the modalities are basically adjuvant in nature. This study was performed to evaluate the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 HER-2/neu) expression in GBC.

The present study was prospective and done in tertiary super-specialty institute of northern India. This was a pilot study, and at the time of completion, 29 samples were found suitable which were later submitted for EGFR and HER-2/neu evaluation. The sample includes both cases of GBC (n=18) and cholecystitis (n=11) as control. (Table 1) After performing necessary processing, slides were incubated with primary antibody (EGFR) ready to use (RTU) BioGenex, India and HER-2/neu dilution 1:600, Dakopatts (Denmark). Then slides were incubated with secondary antibody (Real Envision Detection Kit, Dakopatts, Denmark). Finally in mounted slides, cell membrane staining was used to assess positivity for EGFR and HER-2/neu.

EGFR was positive in 21/29 (72.41%) overall, out of which 14/18 (77.78%) positive in cases and 7/11 (63.64%) positive in control. (Table 1, 3)(Figure 2). For HER-2/neu, it was positive in 21/29 (72.41%) overall, just like in EGFR mentioned above, but positive 12/18 (66.67%) in cases and 9/11 (81.82%) in control respectively.

Despite the efforts by many investigators, GBC continues to represent a major challenge in oncology. Surgical resection remains the only curative treatment for this disease. The roles of radiation, chemoradiation, and chemotherapy in neoadjuvant and adjuvant settings remained to be defined in prospective studies. With further studies based on molecular understanding and developing new targeted therapies, we will be in better position to manage GBC and increase the survival rate.