[Gastrointestinal stromal tumors: clinicopathologic and survival evaluation in Rebagliati Hospital]

To determine the clinical, radiological, histopathological manifestations and survival of patients with gastrointestinal stromal tumor (GIST) in the National Hospital Edgardo Rebagliati Martins (HNERM) from Lima, Perú.

This is a descriptive and retrospective study, which was based on the medical records of 103 patients with confirmed GIST with immunohistochemical. All the patients were evaluated and treated at the HNERM, from January 2002 until December 2010.

In 103 patients between 30 and 88 years the average age was 64 years. The tumor was more frequent in females (52%). The mean disease duration was 7 months. The most frequent form of presentation was gastrointestinal bleeding (48.3%). The diagnosis was made more by endoscopy (50.5%). The prevalence of GISTs by organs was more frequent in stomach (56.3%). The average size of the tumors was 98 mm, 49% had a size between 50 mm and 100 mm, the largest tumor was 260 mm. Tumor stage more frequent was localized (70:9%). GIST associated with another cancer was 9.7% of patients. The predominant histologic pattern was fusiform (73.8%). The 84.5% had low mitotic index. Immunohistochemistry showed expression KIT (CD 117) was 94.17%, CD34 77.5%, Vimentin 96.6%, NSE 84.9%, alpha actin 52.7%, CD56 44.4%, S-100 32.3% and Actin 20%. The tomographic characteristic more frequent was heterogeneous tumor (43.6%).The distribution according to risk classification was: very low risk 3.9%, low risk 28.2, intermediate risk 37.7% and high risk 30.1%. Complete surgical resection was performed in 87.4% of patients and 4.9% of patients received imatinib. The cumulative overall survival at 5 years was 31.07%. In bivariate analysis statistical association was found between surviving with: no presence of cancer associated p = 0.004, CD 34 p = 0.01, low mitotic index p = 0.00 and received surgical treatment p = 0.000. In multivariate analysis one found statistical association of longer survival with smaller tumor size p = 0.015 (CI -3.67, -0.41), localized tumor stage p = 0.036 (CI -5.83, -0.19), lower mitotic index p = 0.038 (CI -0.86, 0.02), asymptomatic patient p=0.009 (CI 1.25, 8.62), no tumor recurrence p = 0.01 (CI -8.49, -1.17), and no metastasis p = 0.001 (CI 2.66, 10.62).

The results of our study were similar to what was reported in international literature. Factors that were associated with longer survival were receiving surgical treatment, patients with smaller tumor size, tumor stage localized, low mitotic index, asymptomatic patient, not tumor recurrence, not metastasis and no cancer associated.