1. Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510060, Guangdong, P.R. China.
2. Department of Radiation Oncology, Sun Yat-sen University Cancer Center.
3. State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center.
4. Department of Radiation Oncology, Cancer Center, First People's Hospital of Foshan Affiliated to Sun Yat-sen University, Foshan, China.
5. The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
*These authors contributed equally to this work.
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.
Keywords: nasopharyngeal carcinoma, intensity-modulated radiotherapy, cervical lymph nodes biopsy, prognosis.