Treatment effects in patients with squamous cell carcinoma of the oral cavity.

A total of 221 patients (155 males, 66 females; stage I, n = 55: stage II, n = 58; stage III, n = 57; stage IV, n = 51) with squamous cell carcinoma of the oral cavity were studied. Tumor localization was as follows: cancer of the tongue, n = 161; cancer of the oral floor, n = 28; cancer of the hard palate, n = 12; cancer of the buccal mucosa, n = 11; and cancer of the gingiva, n = 9. In order to compare the effect of different treatments, three major treatment groups were defined, namely a surgery group, a radiotherapy group and a combination treatment group. Five-year cumulative survival rates showed significant differences between stage classifications (stage I = 91%, stage II = 73%, stage III = 63%, stage IV = 47%; p < 0.01) but not between tumor sites. The 5-year cumulative survival rate was highest for oral floor cancer (80%). In the early-cancer group, the 5-year cumulative survival rate for the surgery group (92%) was significantly higher (p < 0.05) than those for both the radiation (69%) and combination (71%) groups. In the advanced-cancer group, the 5-year cumulative survival rate for the surgery group (74%) was significantly higher (p < 0.05) than those for both the radiation (37%) and combination (51%) groups. No significant difference in regional control rates was observed between the treatment groups. Five-year regional control rates were 86% for cervical untreated patients with T1N0 tumors and 60% for cervical untreated patients with T2N0 tumors. Fourteen N0 cases were treated with neck dissection. Cervical metastasis was found pathologically in 2/14 (14%) of these cases. The 5-year survival rate for patients with cervical recurrences after primary tumor resection was 70% (n = 15). In contrast, the 5-year survival rate for patients with both primary tumor resection and neck dissection was 74% (n = 14) but no significant difference was observed between these 2 groups.