Prognosis was obviously poor in PPSM-treated stage Ib cases, compared with extra PPSM-treated counterparts (P less than 0.01). Out of the PPSM-treated stage Ib cases, those where prophylactic lymph node dissection was performed ran a prognosis similar to the extra PPSM-treated stage Ib cases: it is advisable therefore to perform the prophylactic lymph node dissection actively in the PPSM-treated stage Ib cases. A response rate of 28.6% was achieved with PAV therapy in stage IV cases, with metastases to the skin, subcutaneous tissue, lymph nodes and bone responding to the therapy. PAV therapy, when applied in operable cases, brought about excellent 5-year survival rates as 100% high as in stage Ia, 92.9% in stage Ib, 53.1% in stage II, and 66.9% in stage Ib + II cases. In a randomized, controlled study of bestatin in stage Ib and II cases over about 4 years has revealed that both the disease-free rate and the survival rate were significantly high in the bestatin-treated group, compared with the control group.