A total of 1160 patients with previously untreated laryngeal carcinoma were registered in our hospital between 1979 and 1994. The mean age was 64 years (range: 22-91 years). These patients consisted of 746 cases of glottis, 393 supraglottis, 14 subglottis, and seven multicentric carcinomas. Some trends in their clinical epidemiological status and the laryngeal preservation rate were observed and compaired between the following two periods; 1979-1986 and 1987-1994.
Our conclusions are listed below.
1) The age distribution was similar in both periods. Taking into account the increase in the ratio of early stages (stage I, II), however, it may be that there was a tendency toward older age.
2) The number of patients with glottic carcinoma increased from 356 to 390, whereas, those with supraglottic carcinoma decreased from 200 to 193.
3) The laryngeal preservation rate in glottic carcinomas increased from 58% to 78%, although the proportion of T1 to T2 cases showed an increase of only 7%. The laryngeal preservation rate in T1 and T2 cases increased from 68% to 85%. Similarly, the laryngeal preservation rate in supraglottic carcinoma increased from 10% to 27%, although the proportion of T1 to T2 cases showed an increase of 11%. The laryngeal preservation rate of T1 to T2 cases increased from 24% to 44%. Consequently, it was suggested that the increase in the laryngeal preservation rate in cases of laryngeal carcinoma was dependent on not only an increase in the proportion of T1 to T2 cases, but also on an improvement in their diagnosis and treatment.
