Additional Cervical Lymph Node Biopsy is Not a Significant Prognostic Factor for Nasopharyngeal Carcinoma in the Intensity-Modulated Radiation Therapy Era: A Propensity Score-matched Analysis from an Epidemic Area

Introduction: This study aimed to evaluate the prognostic value of cervical lymph node biopsy and whether different biopsy methods would lead different outcomes in NPC in the intensity-modulated radiotherapy (IMRT) era. Material and Methods: 1492 patients with biopsy-proven, non-metastatic NPC, and treated by IMRT with or without chemotherapy were retrospectively reviewed. Cervical lymph node biopsy was performed in 183 (12.3%) patients: 61(4.1%) by needle puncture and 118(7.9%) by excision biopsy. Propensity-score matching was used to match patients in both arms at an equal ratio. Overall survival (OS), distant metastasis-free survival (DMFS), locoregional relapse-free survival (LRFS), and nodal relapse-free survival (NRFS) were assessed using the Kaplan-Meier method and compared using the log-rank test. Independent prognostic factors were identified using the Cox proportional hazards model. Results: In the original cohort of 1492 patients, patients receiving cervical lymph node biopsy had comparable survival (OS: P = 0.736, DMFS: P = 0.749, LRFS: P = 0.538, NRFS: P = 0.093,) with patients receiving isolated napharynx biopsy. The results for the propensity-match cohort of 316 patients were similar. Interestingly, compared with the control group and needle puncture biopsy group, a slightly lower nodal recurrence rate was observed in the excision biopsy group (P = 0.082 and P = 0.072, respectively). Adjusting for the known prognostic factors in multivariate analysis, cervical biopsy did not cause a higher risk of death, distant metastasis, or nodal relapse. Conclusions: Pretreatment cervical lymph node biopsy is not associated with impaired survival in NPC, suggesting the resist of the biopsy and more aggressive treatment after the biopsy may be unnecessary.