Clinical and histopathological studies on radiotherapy for hypopharyngeal carcinoma

A retrospective analysis was made of radiotherapy for squamous cell carcinoma of the hypopharynx. One hundred and nineteen cases of squamous cell carcinoma of the hypopharynx were treated by irradiation between 1963 and 1979. The overall five-year survival rate was 29 %, and the five-year survival rate excluding the 19 patients given preoperative irradiation was 34 %, the percentages being 34 and 38 % when the deaths caused by other reasons were excluded. The overall five-year local control rate by radiotherapy was 27 %; the five-year local control rates for pyriform sinus at Tsub(1.2), posterior pharyngeal wall at Tsub(1.2) pharyngo-esophageal junction of Tsub(1.2) and T3 were 67, 65, 21 and 15 %, respectively. The rate of tumor disappearance was higher and local recurrence time was prolonged when treatment was combined with chemotherapy (5-FU or BLM), but no improvement was seen in the long term survival rate. According to a multivariate analysis of local control by irradiation, the important factors determining prognosis were T-factor, age and the site of the tumor. Surgical salvage of tumors remaining or relapsing after radiation was performed on 26 patients, and their 5-year survival rate was 41 % (42 % excluding other causes of death). Serial section of surgical specimens from 10 patients showed that the remaining tumors were deeper and more frequently multiple as the T-factor advanced, with almost all showing infiltrative growth. According to Willen's method, the residual tumors were at a high grade of malignancy in the mode of invasion, stage of invasion, and cellular response. (author)