Background: Gastrointestinal stromal tumors (GIST) are uncommon and their prognostic factors remain controversial. The objective of this study was to analyze the clinical and pathological characteristics as well as the prognostic factors of GIST in a sample of Mexican patients.
Methods: We retrospectively analyzed patients admitted with a diagnosis of GIST to a reference center in Mexico between 1997-2007. We analyzed demographic, clinical and histopathological factors of GIST and constructed Kaplan-Meier survival curves which were compared using the log-rank test. Multivari ate analysis was performed using the Cox regression test.
Results: Sixty-two patients were included. The most common tumor site was the small bowel (46.8%). Median tumor size was 7.5 cm. The c-kit and p53 immunoanalysis were positive in 92% and 32.3% of cases, respectively. With a median follow-up of 37 months, the 5 year overall survival and disease free survival were 76.05% and 59%, respectively. By univariate analysis, favourable prognostic factors included being female, a low mitotic rate, tumour size < 10 cm absence of tumour necrosis and negative immunoreactivity for p53; however, only the latter remained significant in the multivariate analysis.
Conclusions: P53 is the strongest prognostic factor independently from mitotic rate or tumour size.