A multifactorial prognostic model for adult soft tissue sarcoma considering clinical, histopathological and molecular data

Soft tissue sarcomas (STS) are malignant mesenchymal lesions with a high de gree of prognostic variability Different prognostic markers such as grading , staging, tumour type and localisation are known. The establishment of the se markers was based on the evaluation at results of extensive cohorts of p atients. Therefore, only the established markers provide us with informatio n about probabilities in relation to other qualities. Considering as many d ifferent markers as possible in one prognostic statement should increase th e value of the resultant information. Therefore, we developed a model invol ving known prognostic markers to formulate an individual prognostic index. In a retrospective analysis, different prognostic factors of 198 adult STS patients with histological tumour free resection margins were evaluated usi ng a multifactorial analysis. On the basis of a Cox-Regression-Model with p roportional hazards, the prognostic factors (tumour type, staging, localisa tion and type of surgical resection) were selected using previous knowledge and a statistical step backward selection procedure adjusting the immunohi stochemical status of p53/Mdm2 expression. On the basis of the baseline sur vival function of our cohort (S-0 (t)), the cumulative probability of survi val for two S (2) and five S (5) years was estimated As a result of our ana lysis the equations S (2) = (e(-00393))(P) and S (5) = (e(-00869))(P) can b e used to estimate the individual two and five-year probability of survival in our cohort. Here p is the result of the amount of the estimated regress ion- coefficients of the exact variables of the respective individual patie nt. This model makes it possible to include all the evaluated prognostic fa ctors which, in turn, increases the accuracy of the prognostic information for individual patients underlining the proportional hazards assumption.