Impact of nodal ratio on survival in recurrent nasopharyngeal carcinoma

Identifying optimal candidates for postoperative adjuvant therapy among regional persistent/recurrent nasopharyngeal carcinoma patients after neck dissection

Purpose

To analyze the clinical outcomes of patients with regional persistent/recurrent nasopharyngeal carcinoma (NPC) who received neck dissection, and to evaluate the clinical benefit of postoperative adjuvant therapy (PAT) based on patients’ positive lymph node counts (PLNs), extracapsular spread (ECS) and preoperative plasma EBV DNA levels.

Methods

From 2003 to 2017, 342 patients with regional persistent/recurrent NPC were included in this study. All patients were treated with neck dissection and 76 patients received PAT. Progression-free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRFS) were compared between groups using propensity score matching (PSM).

Results

152 patients without PAT treatment and 76 patients with PAT treatment were selected by the PSM. There was no significant difference in 2-year PFS (52.4% vs. 61.3%, P = 0.371), 2-year OS (91.9% vs. 90.5%, P = 0.097) or 2-year LRFS (66.3% vs. 67.9%, P = 0.872) between the two groups. However, the application of PAT brought survival benefits to patients in terms of 2-year DMFS (76.5% vs. 84.7%, P = 0.020). PLN, ECS and preoperative EBV DNA level remained independent risk factors for poorer PFS. Accordingly, patients were divided into low-risk and high-risk groups using receiver operating characteristic (ROC) curve; the 2-year PFS rates for two risk groups were 73.4% and 59.1% (P < 0.0001) respectively. The results showed that low-risk patients didn’t benefit from the addition of PAT. However, the 2-year DMFS rate was significantly improved in high-risk PAT-treated patients than those treated by neck dissection alone (83.7% vs. 71.7%, P = 0.023).

Conclusions

PLNs, ECS and preoperative EBV DNA level are associated with the prognosis of patients with regional persistent/recurrent NPC. High-risk patients identified by PLNs, ECS and preoperative EBV DNA level may benefit from the addition of PAT after neck dissection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10150-0.

Establishment of a prognostic scoring model for regional recurrent nasopharyngeal carcinoma after neck dissection

Objective: The main aim of this study was to establish a scoring model to predict risk of progression and survival in patients with regionally recurrent nasopharyngeal carcinoma (NPC).

Methods: Three hundred and forty-eight patients subjected to neck dissection from 2003 to 2017 were included for study. Clinicopathologic information for each patient was analyzed. Independent prognostic factors were selected using the Cox proportional hazards model and incorporated into the scoring model. Concordance index (C-index) and calibration curves were used to verify discrimination and calibration, respectively and the results validated using bootstrap resampling.

Results: Microscopic positive lymph node > 2 [hazard ratio (HR), 2.19; 95% confidence interval (CI), 1.30–3.68; P = 0.003], extranodal extension (HR, 2.75; 95% CI, 1.69–4.47; P < 0.001), and lower neck involvement (HR, 1.78; 95% CI, 1.04–3.04; P = 0.034) were identified from multivariate analysis as independent factors for overall survival (OS). A qualitative 4-point scale was generated to stratify patients into 4 risk groups for predicting OS and progression-free survival (PFS). The novel scoring model demonstrated enhanced discrimination (C-index = 0.69; 95% CI, 0.62–0.76) relative to the original recurrent tumor-node-metastasis (rTNM) staging system (C-index = 0.56; 95% CI, 0.50–0.62), and was internally validated with a bootstrap-adjusted C-index of 0.70. The calibration curve showed good agreement between predicted probabilities and actual observations.

Conclusions: The scoring system established in this study based on a large regionally recurrent NPC cohort fills a gap regarding assessment of risk and prediction of survival outcomes after neck dissection in this population and could be further applied to identify high-risk patients who may benefit from more aggressive intervention.

Contemporary management of the neck in nasopharyngeal carcinoma

Up to 85% of the patients with nasopharyngeal carcinoma present with regional nodal metastasis. Although excellent nodal control is achieved with radiotherapy, a thorough understanding of the current TNM staging criteria and pattern of nodal spread is essential to optimize target delineation and minimize unnecessary irradiation to adjacent normal tissue. Selective nodal irradiation with sparing of the lower neck and submandibular region according to individual nodal risk is now emerging as the preferred treatment option. There has also been continual refinement in staging classification by incorporating relevant adverse nodal features. As for the uncommon occurrence of recurrent nodal metastasis after radiotherapy, surgery remains the standard of care.

Treatment of persistent/recurrent nodal disease in nasopharyngeal cancer

PURPOSE OF REVIEW

Persistent or recurrent disease in the neck lymphatics is an unusual pattern of failure in nasopharyngeal carcinoma (NPC) after definitive radiotherapy or chemoradiotherapy. The purpose of this review is to critically synthesize the current knowledge regarding salvage treatment of this unique form of failure in NPC.

RECENT FINDINGS

Surgery in the form of radical neck dissection has been established as the standard salvage treatment with 5-year regional control of 60--86%. Recent shift in paradigm has resulted in the use of modified or selective neck dissection as salvage surgery in some centers. Risk factors for poor survival outcome include recurrent nodal disease, number of involved lymph nodes, extracapsular extension, high lymph node ratio, and positive resection margin. There are no well controlled studies on the role of additional radiotherapy or chemotherapy to improve local control or survival after salvage neck dissection in this group of patients with regional failure.

SUMMARY

There is limited literature regarding the extent of surgical dissection in treating nodal persistent or recurrent disease. Prospective studies are also needed to determine whether adjuvant therapy improves treatment outcomes.

Prognostic capacity of the lymph node ratio in squamous cell carcinomas of the head and neck

INTRODUCTION AND OBJECTIVES

Lymph node density or lymph node ratio (LNR), defined as the quotient between the total number of positive lymph nodes and the total number of dissected lymph nodes, has demonstrated a prognostic capacity in several tumour models, including patients with head and neck squamous cell carcinomas (HNSCC). The aim of the present study is to analyse the prognostic value of LNR in a wide cohort of patients with HNSCC.

METHODS

We carried out a retrospective study of a cohort of 1,311 patients with HNSCC treated with unilateral or bilateral neck dissections. Of the patients included in the study, 55.0% had lymph node metastases (pN+). We proceeded to calculate the value of the LNR, and its categorization through a recursive partition analysis considering specific survival as the dependent variable.

RESULTS

Three categories were defined according to the value of the LNR with a cut-off point at the values < of .025 and .118. The 5-year specific survival for patients with an LNR less than .025 (n=654, 49.8%) was 87.2%, for patients with a LNR .025-.118 (n=394, 30.1%) it was 51.6%, and for patients with a LNR greater than .188 (n=263, 20.1%) it was 27.3% (P=.0001). According to the results of a multivariate analysis, the LNR significantly related to specific survival.

CONCLUSION

The LNR can be a prognostic variable to be considered in the pathological staging of the lymph nodes.

Neck lymph node status on survival of regionally recurrent or persistent nasopharyngeal carcinoma

The aim of this study was to evaluate the impact of lymph node status from neck dissection pathological specimens on the survival for isolated regional nodal recurrence or persistence after primary treatment of nasopharyngeal carcinoma. Through a retrospective cohort study performed in an academic tertiary referral hospital in Hong Kong. Forty-six patients who underwent a salvage neck dissection between June 2001 and January 2013 for isolated regionally recurrent or persistent nasopharyngeal carcinoma was performed. Informed consent was waived for this retrospective study by The Joint CUHK-NTEC CREC. In the study forty-six patients had a salvage neck dissection for nodal failure with a mean age of 53 and 74% (34) were male. With a mean follow-up of 45.3 months, Overall survival, disease specific survival, loco-regional recurrence free survival, and regional recurrence free survival were 56.5%, 73.9%, 87.0%, and 91.3% respectively. For both univariate and multivariate analysis, patients with a number of positive lymph nodes more than 5 and a lymph node density more than 20% were significantly associated with poorer overall survival. Extracapsular spread and pathological cervical lymph node staging did not have an association with poorer survival. In conclusion, an absolute number of positive lymph nodes more than five and a lymph node density more than 20% were potentially useful prognostic factors affecting survival following a neck dissection for regional residual or recurrent nasopharyngeal carcinoma.