Therapeutic effect and prognostic factors for patients with mucoepidermoid carcinoma of parotid gland

Abstract

Objective To study the therapeutic effect of adjuvant chemotherapy and radiotherapy after operation in patients with mucoepidermoid carcinoma of parotid gland, and to screen the indicators ralated to the prognosis of tumor. Methods Eighty patients with mucoepidermoid carcinoma of parotid gland in First People′ Hospital of Yibin of Sichuan Province from January 2005 to December 2009 were analysed retrospectively in our research. We studied the survival of patients who were treated wtih simple operation(30 cases) or postoperative adjuvant therapy(50 cases). Then we further analyzed the relationships between the prognosis of the patients and some variables (age, gender, smoking, alcohol drinking, lymph node metastasis, distant organ metastasis, treatment method, differentiation degree and T grading). Results Kaplan-Meier survival curves showed that patients with postoperative adjuvant therapy had longer PFS and OS than those without adjuvant therapy (94.4 months vs 69.3 months; 114.9 months vs 96.7 months), with statistical significance (χ2=11.246, P=0.001; χ2=15.803, P=0.001). COX univariate analysis showed that gender (χ2=22.346, P=0.000), smoking (χ2=7.891, P=0.041), lymph node metastasis (χ2=12.371, P=0.005), distant organ metastasis (χ2=9.813, P=0.002), treatment method (χ2=25.261, P=0.000), differentiation degree (χ2=4.361, P=0.006) and T grading (χ2=5.336, P=0.014) were related to the PFS of patients. COX multivariate analysis showed that lymph node metastasis (χ2=11.003, RR=2.827, 95%CI: 1.965-3.851, P=0.011), distant organ metastasis (χ2=7.611, RR=0.472, 95%CI: 0.240-0.775, P=0.016), treatment method (χ2=24.542, RR=5.390, 95%CI: 3.585-9.602, P=0.000), degree of differentiation (χ2=3.221, RR=2.118, 95%CI: 1.845-4.719, P=0.009) and T grading (χ2=4.336, RR=0.804, 95%CI: 0.681-0.916, P=0.024) were related to the PFS of patients. COX univariate analysis showed that smoking (χ2=4.551, P=0.008), alcohol drinking (χ2=11.742, P=0.048), lymph node metastasis (χ2=14.886, P=0.009), distant organ metastasis (χ2=6.713, P=0.005), treatment method (χ2=22.411, P=0.000), degree of differentiation (χ2=8.116, P=0.012) and T grading (χ2=14.443, P=0.035) were related to the OS of patients. COX multivariate analysis showed that lymph node metastasis (χ2=11.711, RR=2.985, 95%CI: 1.521-3.999, P=0.005), distant organ metastasis (χ2=5.390, RR=0.400, 95%CI: 0.201-0.793, P=0.009), treatment method (χ2=19.327, RR=5.086, 95%CI: 3.241-8.006, P=0.000), degree of differentiation (χ2=7.084, RR=2.301, 95%CI: 1.908-4.503, P=0.001) and T grading (χ2=13.229, RR=0.561, 95%CI: 0.348-0.867, P=0.040) were related to the OS of patients. Conclusion Adjuvant radiation and chemotherapy can obviously prolong the PFS and OS for the patients with mucoepidermoid carcinoma of parotid gland. Lymph node metastasis, distant organ metastasis, treatment method, differentiation degree and T grading can greatly influence the prognosis of patients with mucoepidermoid carcinoma of parotid gland, which can be used as independent prognostic indicators for the patients with mucoepidermoid carcinoma of parotid gland. Key words: Mucoepidermoid tumor; Treatment outcome; Prognosis