Abstract
Recently, multiple occurrences of malignant tumors in the same patients are increasing because of a longer life span, and a high cure rate of the first cancers.
During the 25 years, we have encountered 3 cases of oral cancer patients suffering from additional lesions in the oral cavity more than 10 years after the treatment of their first cancers. All of the first and second lesions in the 3 cases we studied were diagnosed as squamous cell carcinomas.
The first case was a 60-year-old woman. She suffered from tongue cancer on the right side, and the lesion was treated with radiotherapy. The second lesion, which occurred on the right side of the maxilla, was found after. 13 years, and it was surgically resected.
The second case was 52-year-old man. He suffered from a cancer on the right side of the oropharynx, which was treated with radiotherapy. The second lesion occurred on the left side of the tongue after 12 years. The tumor was radically resected.
The third case was a 51-year-old woman. She suffered from cancer of the left side of the mouth floor, and the lesion was resected with upper neck dissection. The second lesion occurred on the right side of the tongue after 12 years. The tumor was radically resected. The third lesion was found on the left side of the oropharynx 2 years after treatment of the second lesion, and it was treated with radiotherapy.
The second patient died of a cirrhotic liver, but the other two patients are tumor-free after final treatment for the second or third lesions.
