A Comparative Analysis of Clinical Characteristics and Histomorphologic and Immunohistochemical Spectrum of Gallbladder Carcinoma in Young Adults (< 45 Years) and Elderly Adults (> 60 Years).

Gallbladder carcinoma (GBC) is more frequent after 60 years of age; its behavior in young adults has not been much studied. A retrospective analysis was performed in patients who underwent a cholecystectomy procedure between the years 2001 to 2016. A group of young patients (< 45) were compared with elderly patients (> 60 years) with reference to various clinical, histomorphologic, and immunohistochemical parameters. Statistical analysis was performed using t test and Fisher's test. Survival curves were calculated by Kaplan-Meier actuarial survival curves and log-rank tests. One hundred and one patients with GBC were observed during the study period. Of these, 14 patients (13.9%) belonged to the study group (age range 20 to 45 years) and 43 patients (42.6%) constituted the comparison elderly control group (age range 60 to 80 years). Forty-four pts. were in the middle-aged group (46 to 59 years) and were thus excluded from the study. With reference to age (< 45 and > 60), no significant difference was found in sex (females 64.3% vs 69.8%, p = 0.7), presence of gall stones (64% vs 60%, p = 0.8), advanced disease at presentation (T4) (14.3% vs 7%, p = 0.40), incidental detection of gallbladder carcinoma (28.5% vs 28%, p = 0.9), tumor stage at presentation (stage I/II) (35.7% vs 49%, p = 0.39), and poor differentiation (tumor grades G3) (14% vs 12%, p = 0.79). Full-length involvement (28.5% vs 11.6%, p = 0.015) of the gallbladder and abundant tumor necrosis (43% vs 14%, p = 0.021) were more common in the younger patients group whereas adenosquamous and pure squamous cell carcinoma were predominantly observed in elderly patients. Immunohistochemical studies showed higher percentage of overexpression of p53 and Ki-67 proliferation indices in the younger population. Overall survival in younger patients was 48 months whereas in elderly patients it was 36 months. Histological markers denoting aggressive tumor behavior were observed in gallbladder carcinomas of younger individuals; further studies are needed to delineate the differences in molecular mechanisms involved in progression of the tumor in the two groups.