Prognostic factors for metastatic testicular germ cell tumours: the Memorial Sloan-Kettering cancer model.
Since November 1982, patients treated at Memorial Hospital for advanced germ cell tumours have been allocated to good or poor risk clinical trials by the use of a mathematical model. A probability of complete response (CR) is based upon a patient's actual pre-treatment values of LDH and HCG and the number of metastatic sites. In good risk trials, a regimen consisting of four cycles of etoposide+cisplatin results in a durable proportion of CR of about 90% and causes minimal toxicity. Modifications of standard dose regiments have failed to increase the CR proportion in poor risk patients despite greater toxicity. The data show that about 10% of good risk patients will die despite favourable prognostic features, and about 35% of poor risk patients will achieve a durable CR with standard therapy despite unfavourable clinical characteristics. Therefore better markers of prognosis are needed. Two addition categories of markers are under study at Memorial Hospital. Firstly, the half-life decline of AFP and HCG (a 'post-treatment' marker) measured during the first two months of initial therapy is strongly associated with the likelihood of a CR. A prolonged decline of either AFP or HCG resulted in an inferior survival in both good and poor risk patients. Because few good risk patients had a prolonged marker half-life decline, this observation is being confirmed prospectively in an ongoing randomized trial. However, in poor risk patients, a prolonged half-life marker decline now results in an immediate change to high-dose therapy with autologous stem cell rescue.(ABSTRACT TRUNCATED AT 250 WORDS)