Effect of postoperative radiotherapy in pT1pN1cM0 and pT2p/cN0cM0 oropharyngeal squamous cell carcinoma

Objectives/Hypothesis

Consulting of patients with oropharyngeal carcinoma, classified as pT1pN1cM0 and pT2p/cN0cM0, about postoperative radiotherapy is a precarious task as data are lacking. The aim of this study was to evaluate the effects of postoperative radiotherapy for patients with intermediate-stage oropharyngeal carcinoma.

Study Design

Multicentric retrospective study.

Methods

This analysis was conducted at seven Austrian institutions and included data of patients treated between 2000 and 2012. A total of 81 patients with oropharyngeal squamous cell carcinoma were included, of whom 33 patients received postoperative radiotherapy. p16 status determined by immunohistochemistry was available in 68 patients.

Results

Median follow-up was 47.9 months. Postoperative radiotherapy showed no benefits in regard to overall survival (P = .701). In contrast, disease-free survival was significantly shortened in all patients without postoperative radiotherapy (P = .001). When dividing the cohort in dependence of p16, p16-positive patients did not benefit from postoperative radiotherapy regarding overall and disease-free survival (P = .934 and P = .102), whereas p16-negative patients showed improved disease-free survival after postoperative radiotherapy (P = .007). Multivariate analysis showed that outcome of postoperative radiotherapy is dependent on p16 status.

Conclusions

In terms of disease-free survival, patients with p16-negative tumors may benefit from postoperative radiotherapy, whereas survival of p16-positive patients is good regardless of additional treatment.

Level of Evidence

4 Laryngoscope, 2017

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