[Problems in the treatment of early cancer in major organs--thyroid cancer]

In order to establish the concept of early carcinoma of the thyroid and the operative method, 97 patients with cancer of the thyroid measuring less than 1cm in maximum diameter were studied from among 939 patients with thyroid cancer treated at the Second Department of Surgery, Shinshu University School of Medicine, between 1953 and 1984. After excluding occult carcinoma, minimal carcinomas measuring less than 0.5 cm almost never showed metastases to lymph nodes or distant sites, being therefore, equipped with conditions required for early cancer. Since the detection of minimal carcinomas measuring less than 0.5 cm is difficult, however, problems arise as to its clinical application. The prognosis of minimal carcinomas measuring less than 1cm, on the other hand, showed no remarkable difference from that of carcinomas measuring less than 0.5 cm. At present, consequently, minimal carcinomas measuring less than 1cm after exclusion of occult carcinoma may be classified as early carcinoma. No removal of regional lymph nodes is required for carcinoma measuring less than 0.5 cm in the operative procedure. For minimal carcinomas measuring between 0.5 and 1.0 cm, it is necessary to perform modified neck dissection. Strict follow-up observation is necessary for cancers under the histopathological diagnosis of encapsulated type (invasive type) or infiltrative type.