Prognostic stratification of patients with AJCC 2018 pStage IVB oral cavity cancer: Should pT4b and pN3 disease be reclassified?

The prime objective of tumour ablation in oral squamous cell carcinoma (OSCC) is the removal, with a 'margin' of normal tissue, of the whole tumour. Definition of what constitutes margin involvement varies. This study aims to examine the factors associated with close and involved surgical margins in the management of OSCC. A cohort of 200 consecutive patients with previously untreated OSCC provided the material for the study. Various clinical, operative and pathological parameters were related to the status of the surgical margin, as well as time to recurrence, and survival. Cox regression analysis of the survival was also undertaken. Of the 200 patients 107 (53.5%) had clear margins, 84 (42%) close and 9 (4.5%) involved. Poor correlation was found between the status of the surgical margin and clinical factors, but in contrast high correlation between histological indicators of aggressive disease and close or involved surgical margins. These results imply that close surgical margins in OSCC could be regarded as an indictor of aggressive disease.

Standardised reporting of head and neck cancer resections according to guidelines issued by the UK Royal College of Pathologists was introduced as a routine procedure in 1998. The guidelines include definitions of "mucosal", "deep", "clear", "close" and "involved" surgical margins. This study of routine diagnostic material describes the frequency, type and morphological features of involved margins, and assesses the influence of tumour site and pathological T and N stage. 301 consecutive radical resection specimens for oral/oropharyngeal squamous cell carcinoma assessed according to the guidelines were appraised. 70 resections (23%) had involved margins. The frequency was related to primary tumour site, and pathological T and N stage. Mucosal involvement was evident in 11 resections, bone in 10, and deep soft tissue in 61-12 resections had multiple category involvement. Both anatomical factors and histological "markers" of tumour characteristics influence the status of surgical resection margins.