Tumor thickness versus depth of invasion - Analysis of the 8th edition American Joint Committee on Cancer Staging for oral cancer

Richard Dirven; Ardalan Ebrahimi; Nikolaus Moeckelmann; Carsten Erich Palme; Ruta Gupta; Jonathan Clark

doi:10.1016/j.oraloncology.2017.09.007

Tumor thickness versus depth of invasion - Analysis of the 8th edition American Joint Committee on Cancer Staging for oral cancer

Oral Oncol. 2017 Nov:74:30-33. doi: 10.1016/j.oraloncology.2017.09.007. Epub 2017 Sep 19.

Authors

Richard Dirven¹, Ardalan Ebrahimi², Nikolaus Moeckelmann³, Carsten Erich Palme⁴, Ruta Gupta⁵, Jonathan Clark⁶

Affiliations

¹ Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia. Electronic address: dirvenrichard@hotmail.com.
² Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia; Department of Head & Neck Surgery, Liverpool Hospital, Sydney, Australia; Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Sydney, Australia.
³ Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia.
⁴ Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia; Central Clinical School, University of Sydney, Sydney, Australia.
⁵ Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia; Central Clinical School, University of Sydney, Sydney, Australia; Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney, Australia.
⁶ Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Sydney, Australia; Central Clinical School, University of Sydney, Sydney, Australia; South West Clinical School, University of New South Wales, Sydney, Australia.

PMID: 29103748
DOI: 10.1016/j.oraloncology.2017.09.007

Abstract

Objectives: The primary aim of this study is to compare the effect of using tumor thickness versus depth of invasion (DOI) to determine the 8th edition AJCC T-category on survival in a large cohort of OSCC.

Materials and methods: A retrospective cohort study of patients whose clinicopathologic information had been collected prospectively into a dedicated head and neck database. 927 patients with oral SCC were identified in this cohort, with the final study population including 456 patients with complete information on DOI, tumor thickness, T and N staging and follow-up.

Results: 26 (5.7%) patients had a different AJCC 8 T category when using thickness instead of depth. 15 were upstaged from T1 to T2, 10 upstaged from T2 to T3 and 1 down staged from T2 to T1. Additionally, similar stratification of disease-specific and overall survival curves were found for T category based on DOI and thickness.

Conclusion: The T category and TNM stage prognostic performance of 8th edition AJCC staging of oral cancer is similar regardless of whether DOI or thickness is used as the T-category modifier. In centers without complete DOI data it is reasonable to impute thickness for retrospective survival analyses using the 8th edition of the AJCC staging system.

Keywords: AJCC 8; Depth of invasion (DOI); Disease-specific survival; Oral SCC; Overall survival; Staging; T category; Thickness.

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Carcinoma, Squamous Cell / pathology*
Carcinoma, Squamous Cell / therapy
Female
Humans
Male
Middle Aged
Mouth Neoplasms / pathology*
Mouth Neoplasms / therapy
Neoplasm Invasiveness*
Neoplasm Staging
Prognosis
Retrospective Studies
Survival Analysis
Young Adult