Multivariate Analysis of the Prognostic Factors in 230 Surgically Treated Oral Mucosal Malignant Melanomas

PURPOSE:To analyze the prognostic factors which influence the survival rates in oral mucosal malignant melanoma patients.METHODS:230 consecutive patients with oral mucosal malignant melanoma were included in the study. There were 141 males and 89 females.34 were in (TNM) I stage, 87 in II stage and 109 in III stage. Cox proportional hazards model was used to analyze the statistically significant prognostic factors. Kaplan-Meier method was used to analyze the survival rate under the different levels of the different factors and Log rank method for comparison of the distribution of the different survival rates.RESULTS:The prognostic factors include the thickness of the tumor, cervical lymph node metastasis, the presence or absence of ulceration and the anatomic sites. The P value and the relative risk were P<0.001, RR=1.868; P<0.001, RR=1.685; P<0.001, RR=1.411; P=0.008, RR=0.747, respectively. The different factors were independent with each other. The factors of sex (P=0.136), age (P=0.721) and the surgical method used (P=0.944) had no influence on survival rates in this study.CONCLUSIONS:The significant prognostic factors which influence the survival rates in oral mucosal malignant melanoma patients were similar to that in the skin malignant melanoma patients. The factors did not have factor-by-factor interactions. Surgery alone is not the best treatment of choice for oral mucosal melanoma.