Clinical prognostic factors in locally advanced nasopharyngeal carcinoma in Moroccan population

Nasopharyngeal carcinoma is a distinct cancer of head and neck by its pathology, etiology, epidemiology and clinical behavior. Morocco is considered an endemic region with intermediate incidence. The aim of our report is to underline some clinical determinants of survival in locally advanced disease.

We conducted a retrospective study from January 2003 to December 2005. All patients with undifferentiated nasopharyngeal carcinoma treated in the National Institute of Oncology of Rabat, Morocco were recorded. Classified stage II to IVB disease according to TNM classification adopted by the AJCC (American Joint Committee of Cancer) 6th edition.

The study included 339 patients, 122 women and 217 men (sex-ratio: 1.7). Mean age was 43 years old (range: 6-91years). Median duration to diagnosis was 6 months (range: 1-72) presenting symptoms at diagnosis were predominantly cervical lymph node in 79%. Forty- two patients have T1 tumors, 159 = T2 tumors, 64 = T3 tumors and 69 = T4 tumors. Sixty-five patients do not have lymph-node involvement, 49 have N1, 128 have N2 and 95 have N3. Three patients were at stage IIA, 57 patients were at stage IIB, 40 patients were at stage III, and 57 patients were at stage IVA and the remaining 96 patients were at stage IVB. Eighty-seven percent of patients underwent sequential chemoradiation and 17% underwent concurrent chemo-radiation (CTR). Response to induction chemotherapy was assessed in 235 patients. There were 31 patients with complete response and 59 patients have partial response. Complete response to radiotherapy was reached in 235 patients. Mean overall survival (OS) was 66.2%. Gender was a prognostic factor of OS (p=0.045) and DFS favoring women. Age wasn't a prognostic factors determining the outcome with no difference between patients aged more than 40 years old and patients younger. Tumor size was not a determinant of survival with a non-significant p in OS and DFS (0.27 and 0.46 respectively) but T4 stage patients appear to have a worse prognosis. Lymph node involvement was significantly determining the outcome either in OS and DFS (p=0.001 and 0.009 respectively). TNM stage was also a significant prognostic factor in OS but not in DFS favoring those with early stage (p= 0, 004 and p= 0, 13 respectively). The treatment strategy was not a significant prognostic factor with no difference between patients who underwent sequential or concurrent chemoradiation (OS p= 0, 48 and DFS p= 0, 9). In multivariate analysis, lymph-node involvement is the most significant factor.

Our findings were mostly concordant with the literature data in endemic areas for TNM staging; however we are limited by the bias of retrospective studies. Prospective studies would be more accurate to define those prognostic factors in our population.

UCNT, prognostic factors, endemic areas, lymph node involvement.