Stromal tumors of the digestive tract. Prognostic value of mitotic index.

OBJECTIVE: We analyzed the prognostic factors and evaluated the usefulness of mitotic index to predict the behavior of gastrointestinal stromal tumors (GIST). PATIENTS AND METHODS: Fifty three patients operated on for stromal tumors of the digestive tract were studied retrospectively. Mean follow-up was 6 years. The number of mitosis/10 high power fields was the definitive criterion for classification, regardless of their inmunohistologic differentiation. Twelve tumors had 0 mitoses, 34 from 1 to 9 mitoses, and 7 had > or = 10 mitoses. The survival rate was analyzed and the morphological characteristics and evolution were correlated according to mitotic index. RESULTS: The incidence of advanced illness was related to the number of mitoses: 29% in the group with 1 to 9 mitoses, and 86% when there were > or = 10 mitoses. The recurrence intervals were 44 and 8 months respectively. No tumor with 0 mitoses evolved aggressively. The survival rate was significantly related (p < 0.001), to the mitotic index. The group with 0 mitoses had a survival rate of 100% after 10 years, those with 1 to 9 mitoses 69% and those with > or = 10 mitoses 14%. The other factors which influenced the prognosis (location, size, local invasion and resection) depended, as well, on the mitotic index. CONCLUSION: The classification of digestive tract stromal tumors by mitotic index is an efficient method because it distinguishes 3 entities with different biological behavior in the long term.

[Early gastric and superficial muscle gastric cancer. Contribution of morphology to prognosis]. / Cáncer gástrico precoz y muscular superficial. Aportación de la morfología al pronóstico.

The purpose of the study was to correlate the depth of invasion in the gastric wall with survival in gastric cancer. In order to do so, we reviewed 48 patients harboring 58 gastric adenocarcinomas that did not exceed the superficial half of the muscularis propia. The patients were followed for up to a period of a least 5 years after surgery. The depth of invasion of the tumour in the gastric wall was found to correlate significantly with the invasion of lymphatic capillaries (p < 0.001) and with the finding of lymph node metastasis (mucous cancer 9%, submucous cancer 36% and superficial muscularis propia cancer 40%; p < 0.05). The size of the tumour was directly related with the depth of the cancerous invasion. Survival after 5 years varies significantly according to size of tumour (< 2 cm = 100%, 2-5 cm = 86% and > 5 cm = 33%; p < 0.0001), invasion of lymphatic capillaries (p < 0.01) and depth of the cancerous invasion (mucous cancer 94%, submucous cancer 84% and superficial muscularis propia cancer 67%; p < 0.05). The Lauren diffuse type or the multicentric cancer had a worse prognosis. The depth of invasion in the gastric wall appears to be the most important prognostic factor, since both the size of the tumor and the lymphatic involvement are related to it. When the tumour is limited to the muscularis propia, the survival rate is intermediate between early gastric cancer and advanced cancer.