Postoperative radiotherapy is associated with improved survival in pT1-2N1 oral and oropharyngeal cancer without adequate neck dissection

Background

To assess the benefit of postoperative radiotherapy in patients with pT1-2N1M0 oral and oropharyngeal cancer by the quality of neck dissection.

Methods

In the Surveillance, Epidemiology, and End Results database, pT1-2N1M0 oral and oropharyngeal cancer patients treated by primary tumor resection and neck dissection with or without radiotherapy were included between 2004 and 2015. Univariate and multivariate analysis were used to explore the effect of adjuvant radiotherapy on 5-year overall survival (OS) and disease-specific survival (DSS) among different quality of neck dissection.

Results

Of the 1765 patients identified, 1108 (62.8%) had oral cancer, 1141 (64.6%) were men, and 1067 (60.5%) underwent adjuvant radiotherapy. After adjusting for confounding factors, postoperative radiotherapy reduced the adjusted hazard ratio (aHR) of 5-year OS to 0.64 (95% confidence interval [CI] 0.49–0.84) in those with < 18 lymph nodes (LNs) removed, but not in those with 19–24 LNs removed (aHR 0.78; 95% CI 0.73–1.13), and in those with ≥ 25 LNs removed (aHR 0.96; 95% CI 0.75–1.24). For 5-year DSS, similar effect was observed. The adjusted hazard ratio was 0.66 (95% confidence interval, 0.45–0.97) in those with < 18 LNs. The protective effect was not seen in those with 18–24 LNs (aHR 1.07; 95% CI 0.59–1.96), and in those with ≥ 25 LNs (aHR 1.12; 95% CI 0.81–1.56). Sensitivity testing also showed a robust protective effect of postoperative radiotherapy in patients with < 18 LNs removed.

Conclusion

Radiotherapy was associated with improved survival in pT1-2N1M0 oral and oropharyngeal cancer patients without adequate neck dissection.

Impact of Lymph Node Yield in Patients Undergoing Total Laryngectomy and Neck Dissection

OBJECTIVES

To determine the impact of lymph node yield (LNY) in patients undergoing neck dissection at the time of total laryngectomy (TL). To determine the impact of radiation therapy (RT) on LNY.

METHODS

Retrospective review of LNY and clinical outcomes in 232 patients undergoing primary or salvage total laryngectomy (TL) with ND.

RESULTS

Preoperative RT significantly decreased mean LNY from 31.7 to 23.9 nodes (P < .001). In primary TL patients, age (P < .001) and positive margins (P = .044) were associated with decreased OS. In salvage TL patients, only positive margins was associated with poorer OS (P = .009). No LNY cutoff provided significant OS or DFS benefit.

CONCLUSIONS

Radiotherapy significantly reduces LNY in patients undergoing TL and ND. Within a single institution cohort, positive margins, but not LNY, is associated with survival in both primary and salvage TL patients.Level of Evidence: 4.