Clinical and prognostic significance of TROP2 expressionin gastric cancers

Objective: TROP2 expression is being investigated in many cancer types and evaluated as a molecular target. We aimed to investigate the rate of TROP2 expression, its relationship with clinical and pathological parameters, and its effect on prognosis in patients with operated gastric cancer followed up in our clinic. Material – Method: The data of 95 patients who underwent total-subtotal gastrectomy with the diagnosis of gastric cancer in Afyonkarahisar Health Sciences University Faculty of Medicine, Department of Medical Oncology between 15.03.2012 and 01.03.2021 were retrospectively analyzed. 83 patients were included in the study. In sections taken from the pathology blocks of the patients, TROP2 antibody was evaluated by immunohistochemical method and scored according to the literature. Results: A total of 83 patients, 56 (67.5%) male and 27 (32.5%) female, were evaluated in our study. TROP2 was positive in 43 (51.8%) patients and negative in 40 (48.2%) patients. When evaluating the relationship between TROP2 expression and overall survival (OS), the median OS of TROP2 positive patients was 13.89 months (95% CI 8.26 to 19.52), and the median OS of TROP2 negative patients was 28.91 months (95% CI 11.42 to 46.39). TROP2 positivity was found to have a statistically significant effect on OS (p=0.038). The median disease-free survival (DFS) of TROP2-positive patients was 11.89 months (95% CI 4.76 to 19.02), while the median DFS of TROP2-negative patients was 43.37 months (95% CI 0.00 to 64.59). The median progression-free survival (PFS) of TROP2 positive patients was 5.19 months (95% CI 4.46 to 5.91), while the median PFS of TROP2 negative patients was 5.29 months (95% CI 3.60 to 6.97). There was no statistically significant relationship between TROP2 and DFS (p=0.116) and PFS (p=0.874). A statistically significant relationship was found in univariate analysis between OS and TROP2 expression (p=0.041), presence of recurrence (p<0.0001), age at diagnosis (p<0.0001), ECOG (p=0.040), stage (p<0.0001), surgical margin (p=0.002), tumor localization (p =0.007), metastasis status at diagnosis and follow-up (p<0.0001), liver metastasis (p=0.000), and peritoneal metastasis (p=0.012). In multivariate analyzes, statistically significant correlations were found between TROP2 expression (p=0.018), ECOG, stage, surgical margin, and liver metastasis and OS. Conclusion: In our study, it was determined that TROP2 positivity significantly shortens OS in gastric cancers and is an independent prognostic factor. In conclusion, positive TROP2 expression in gastric cancers association with poor survival was clearly demonstrated in the present study. We suggest that TROP2 may be a useful prognostic biomarker and a promising therapeutic target for gastric cancers. Nevertheless, further studies are required to corroborate the clinical utility of TROP2 expression and TROP2-targeted therapies in gastric cancers.