Benefits of local tumor excision and pharyngectomy on the survival of nasopharyngeal carcinoma patients: a retrospective observational study based on SEER database

Abstract

Background: There is ongoing debate about surgery of primary site in nasopharyngeal carcinoma patients.

Methods: 3919 patients with nasopharyngeal carcinoma identified in the SEER registry between 2004 and 2013. The benefit of surgery of primary nasopharynx tumor site on overall and cancer-specific survival was assessed by risk-adjusted multivariate Cox proportional hazard regression and propensity score matching modeling.

Results: Surgery was marginally associated with better overall survival (hazard ratio (HR) = 0.816, 95% CI 0.656-1.015, p = 0.07) and cancer-specific survival (HR = 0.749, 95% CI 0.552-1.018, p = 0.06) in the propensity score model. Among 398 cases who underwent primary site surgery, 282 (70.85%) received local tumor excision and 79 (20.31%) received pharyngectomy. Local tumor excision and pharyngectomy had almost the same effect on survival in propensity score matching analysis. The benefit was significant in subgroups of white, age <60 year, and patients with T3, N1, M0, AJCC stage III, or moderately differentiated tumors. Further survival analysis showed surgery to promote survival in both radiotherapy and non-radiotherapy patients.

Conclusion: This is the first population-based analysis using propensity score model to provide evidence of a positive impact of surgery on survival in nasopharyngeal carcinoma. Moreover, surgery demonstrated the significant benefit in subgroups of patients with specific clinical characteristics.

Keywords: Epidemiology and End results (SEER) database; Local tumor excision; Nasopharyngeal carcinoma (NPC); Pharyngectomy; Propensity score.

Fig. 1

Flow diagram

Fig. 2

Kaplan–Meier curves stratified by surgery. Y-axis label “Survival probs” means survival probabilities. a, b Kaplan–Meier curves among unmatched patients stratified by surgery types for all-cause death (a, Log rank test p < 0.0001) and nasopharyngeal carcinoma-specific death (b, Log rank test p = 0.0003). c, d Kaplan–Meier curves among matched patients stratified by surgery/non-surgery for all-cause death (c, Log rank test p = 0.0685) and nasopharyngeal carcinoma-specific death (d, Log-rank test p = 0.0605). e, f Kaplan Meier curves among matched patients stratified by surgery type local tumor excision and pharyngectomy for all-cause death (e, Log rank test p = 0.3502) and nasopharyngeal carcinoma-specific death (f, Log-rank test p = 0.3679)

Fig. 3

Kaplan Meier curves among patients stratified by surgery for nasopharyngeal carcinoma-specific death and all-cause death in patients with RT (a all-cause death, Log-rank test p = 0.0033; b cancer-specific death Log rank test p = 0.0038) and in patients without RT (c all-cause death, Log-rank test p < 0.0001; d cancer-specific death Log rank test p < 0.0001). Y-axis label “Survival probs” means survival probabilities

Fig. 4

Treatment trend of NPC. Trend of nonsurgery (a) and surgery (b) in all patients (line), patients with radiation (dot line) and patients without radiation (dash line). c Trend of local tumor excision in all patients (line), patients with radiation (dot line) and patients without radiation (dash line). d Trend of pharynectomy in all patients (line), patients with radiation (dot line) and patients without radiation (dash line)