The utility of postoperative radiotherapy in intermediate-risk oral squamous cell carcinoma

T Liu; M David; M Batstone; J Clark; T-H Low; D Goldstein; A Hope; A Hosni; B Chua

doi:10.1016/j.ijom.2020.06.006

The utility of postoperative radiotherapy in intermediate-risk oral squamous cell carcinoma

Int J Oral Maxillofac Surg. 2021 Feb;50(2):143-150. doi: 10.1016/j.ijom.2020.06.006. Epub 2020 Jun 29.

Authors

T Liu¹, M David², M Batstone³, J Clark⁴, T-H Low⁵, D Goldstein⁶, A Hope⁷, A Hosni⁷, B Chua⁸

Affiliations

¹ Oral and Maxillofacial Surgery, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia; Faculty of Medicine, University of Queensland, Herston, Queensland, Australia. Electronic address: timothy.liu@health.qld.gov.au.
² School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia.
³ Oral and Maxillofacial Surgery, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia; Faculty of Medicine, University of Queensland, Herston, Queensland, Australia.
⁴ Central Clinical School, University of Sydney, Camperdown, New South Wales, Australia; Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia; Royal Prince Alfred Institute of Academic Surgery, Sydney Local Health District, Sydney, Australia.
⁵ Central Clinical School, University of Sydney, Camperdown, New South Wales, Australia; Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia.
⁶ Department of Otolaryngology - Head and Neck Surgery, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, Canada.
⁷ Department of Radiation Oncology, University of Toronto and Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
⁸ Faculty of Medicine, University of Queensland, Herston, Queensland, Australia; Radiation Oncology, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia.

PMID: 32616305
DOI: 10.1016/j.ijom.2020.06.006

Abstract

The effectiveness of postoperative radiotherapy (PORT) in improving outcomes remains debatable for oral squamous cell carcinoma (OSCC) patients with pathological intermediate-risk factors (IRFs) after surgery. A retrospective analysis was conducted on 432 intermediate-risk OSCC patients defined by histological reporting of close margin (<5mm), early nodal disease (pN1), depth of invasion/tumour thickness ≥5mm, perineural invasion, and/or lymphovascular invasion. Outcomes measured were disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). PORT was associated with an improvement in 5-year DFS on univariable analysis (80% vs 71%; P=0.044), but this did not remain significant on multivariable analysis. PORT was not associated with differences in DSS or OS. The surgical salvage rate was similar in the PORT and surgery-only groups (41% vs 47%; P=0.972). Perineural invasion was found to be an independent predictor of inferior DSS (hazard ratio (HR) 2.19), DFS (HR 1.89), and OS (HR 1.97). Significantly worse outcomes were observed for patients with ≥4 concurrent IRFs. The application of PORT was associated with lower rates of recurrence, but the benefit was less apparent on mortality. Patients with perineural invasion and multiple concurrent IRFs were found to be at greatest risk, representing a subset of intermediate-risk OSCC patients who may benefit from PORT.

Keywords: Histological risk factor; Intermediate-risk; Oral cancer; Radiotherapy; Squamous cell carcinoma.

MeSH terms

Carcinoma, Squamous Cell* / pathology
Head and Neck Neoplasms*
Humans
Mouth Neoplasms* / pathology
Neoplasm Recurrence, Local / pathology
Neoplasm Staging
Prognosis
Retrospective Studies
Squamous Cell Carcinoma of Head and Neck