Lack of any Association between Season of Diagnosis and Survival of Gastric Cancer Cases in Kayseri, Turkey

Background: The influence of season of diagnosis on cancer survival has been an interesting issue for many years. Most studies have shown a possible association between seasonality and survival in some cancers. We aimed to investigate whether there is an association between season of diagnosis and survival in patients with gastric cancer. Materials and Methods: We reviewed retrospectively the files of 279 histologically proven gastric cancer patients. According to diagnosis date, the patients were grouped into 4 seasons of diagnosis groups, spring, summer, autumn, and winter. Results: There was no significant differences when the overall survival rates of the patients were compared according to the patients' season of diagnosis (p: 0.871). Median overall survival rates were 22.0 (14.5-29.5) months for the patients who were diagnosed in spring, 24.0 (12.4-35.6) for summer, 18.0 (9.96-26.0) for autumn and 21.0 (16.3-25.7) for winter. Median disease-free survival rates were 66.0 (44.1-68.1) months for the patients who were diagnosed in spring, 28.0 (17.0-39.0) for summer, 22.0 (0-46.4) for autumn and 23.0 (17.5-28.5) for winter. While the rate was best for the patients diagnosed in spring the differences were not statistically significant (p= 0.382). Conclusions: On the basis of the above results the season was not suggested as contributing to prognosis in gastric cancer cases in Kayseri, Turkey.