Margin to tumor thickness ratio - A predictor of local recurrence and survival in oral squamous cell carcinoma

Gregor Heiduschka; Sohaib A Virk; Carsten E Palme; Sydney Ch'ng; Michael Elliot; Ruta Gupta; Jonathan Clark

doi:10.1016/j.oraloncology.2016.01.010

Margin to tumor thickness ratio - A predictor of local recurrence and survival in oral squamous cell carcinoma

Oral Oncol. 2016 Apr:55:49-54. doi: 10.1016/j.oraloncology.2016.01.010. Epub 2016 Feb 6.

Authors

Gregor Heiduschka¹, Sohaib A Virk², Carsten E Palme³, Sydney Ch'ng⁴, Michael Elliot³, Ruta Gupta⁵, Jonathan Clark⁶

Affiliations

¹ Department of Head and Neck Surgery, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia; Department of Otorhinolaryngology - Head and Neck Surgery, Medical University of Vienna, Austria. Electronic address: Gregor.heiduschka@meduniwien.ac.at.
² University of New South Wales, Randwick, New South Wales, Australia.
³ Department of Head and Neck Surgery, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia.
⁴ Department of Head and Neck Surgery, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia; The Institute of Academic Surgery at RPA, University of Sydney, NSW, Australia.
⁵ Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
⁶ Department of Head and Neck Surgery, Chris O'Brien Lifehouse, Camperdown, New South Wales, Australia; Central Clinical School, The University of Sydney, Sydney, New South Wales, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, New South Wales, Australia.

PMID: 26861256
DOI: 10.1016/j.oraloncology.2016.01.010

Abstract

Objectives: To assess whether small oral squamous cell carcinomas (OSCC) require the same margin clearance as large tumors. We evaluated the association between the ratio of the closest margin to tumor size (MSR) and tumor thickness (MTR) with local control and survival.

Methods and methods: The clinicopathologic and follow up data were obtained for 501 OSCC patients who had surgical resection with curative intent at our institution. MTR and MSR were computed and their associations with local control and survival were assessed using multivariable Cox-regression model. Survival curves were generated using the Kaplan-Meier method.

Results: MTR was a better predictor of disease control than MSR. MTR was a predictor of local failure (p=0.033) and disease specific death (p=0.038) after adjusting for perineural invasion, lymphovascular involvement, nodal status, and radiotherapy. A threshold MTR value of 0.3 was identified, above which the risk of local recurrence was low.

Conclusion: The ratio of margin to tumor thickness was an independent predictor for local recurrence and disease specific death in this cohort. A MTR>0.3 can serve as a useful tool for adjuvant therapy planning as it combines tumor thickness and margin clearance, two well established prognostic factors. The minimum safe margin can be calculated by multiplying the tumor thickness by 0.3. Further prospective studies in other institutions are warranted to confirm the prognostic utility of MTR and assess the generalizability of our threshold values.

Keywords: Margin; OSCC; Prognostic marker; Thickness.

MeSH terms

Aged
Carcinoma, Squamous Cell / pathology*
Carcinoma, Squamous Cell / surgery
Disease-Free Survival
Female
Humans
Male
Middle Aged
Mouth Neoplasms / pathology*
Mouth Neoplasms / surgery
Neoplasm Recurrence, Local / pathology*
Neoplasm Recurrence, Local / prevention & control
Prognosis
Retrospective Studies
Risk Assessment / methods
Survival Analysis