While the survival rate of malignant tumor patients is recently improving along with progress in the medical care technology, the incidence of secondary cancer after the cure of the first cancer is also increasing because of the aging of patients. An increase in the incidence of malignant tumor of other organs in addition to primary malignant skin cancer has also been noted in my department. I report on the polyoncosis cases I experienced during the 2 years from January 1995 to December 1996.
Of the malignant skin tumor patients treated during the 2 years, polyoncosis was observed in 2 of the 3 patients with Paget disease and 5 of the 30 patients with squamous cell carcinoma. The types of duplicate cancers included lung cancer (3), gastric cancer (2), laryngeal cancer (2), hepatocelular carcionoma (1), prostate carcinoma (1) and multiple myeloma (1) . One patient had 3 cancers and another had 4 cancers. The age of patients ranged from 66 to 81 years old (mean 72.2 years old) .
A high healing ratio of malignant skin tumor can be obtained in many cases by considerably less invasive methods. On the other hand, radical invasion is needed to cure the malignant tumor of other organs, and the treatment method is restricted by various considerations including the age, lesion, progress of cancer, prognosis, general condition and the will of patient. In this regard, I try to communicate with the patient and his/her family, and obtain their understanding so that he/she can receive the treatment satisfactory to him/her.