Can neoadjuvant chemotherapy improve survival in stage T3-4N1 nasopharyngeal carcinoma? A propensity matched analysis

Background To estimate the efficacy of neoadjuvant chemotherapy (NCT) in stage T3-4N1 nasopharyngeal carcinoma (NPC). Methods Data on stage T3-4N1 NPC patients treated with concurrent chemoradiotherapy (CCRT) with or without NCT at the Sun Yat-sen University Cancer Center between January 2006 and December 2013 were retrospectively reviewed. Propensity score matching (PSM) was carried out to balance prognostic factors in NCT followed by CCRT (NCT + CCRT) group and CCRT group in a 1:1 ratio. Survival outcomes of matched patients in the two groups were compared, and prognostic factors were identified using Cox regression model. Results A total of 282 patients were involved in this study, with 136 of NCT + CCRT group and 146 of CCRT group. After PSM, 85 pairs of patients were selected. There were no significant differences in 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and recurrence-free survival (RFS) between NCT + CCRT group and CCRT group (81.0% vs. 77.5%,P = 0.750; 85.8% vs. 88.1%,P = 0.495; 92.5% vs. 93.9%,P = 0.759; 81.0% vs.77.5%,P = 0.919, respectively). Multivariate analysis found that smoking history (P = 0.044) and T classification (P = 0.027) were independent prognostic factors for OS, lymph node diameter (P = 0.032) was independent prognostic factor for LRFS, positive pretreatment lymph node condition (PLNC), which was defined as the lymph node necrosis or confluent, was independent prognostic factor for DRFS (P = 0.007), and RFS (P = 0.009). Lower 5-year OS (82.7% vs. 94.1%,P = 0.014), DRFS (79.3% vs. 96.2%,P = 0.003), and RFS (62.4% vs. 86.8%,P = 0.001) were found in positive PLNC group compared with negative PLNC group. In terms of toxicities, the incidences of acute hematological Grade 3-4 adverse events (AEs) were higher in NCT + CCRT group compared with CCRT group (P < 0.05), while no significant difference was observed in the rates of non-hematological Grade 3-4 AEs between these two groups (P > 0.05). Conclusions Additional NCT is not associated with improved survival outcomes for patients with stage T3-4N1 NPC, but bring increased hematological Grade 3-4 AEs. PLNC is independent prognostic factor in stage T3-4N1 NPC, with positive PLNC correlating with poor survival outcomes.