37. Understanding the clinical utility and prognostic implications of the new AJCC8 staging system for cutaneous squamous cell carcinoma: A survey of head and neck cancer specialists

Abstract

Background: In order to have clinical relevance and assist in treatment decisions, a cancer staging system must stratify patients into prognostically meaningful groups; outcomes should be homogenous within groups, but distinct between them (AJCC8, 2017). The staging system for head and neck cutaneous squamous cell carcinoma (HNcSCC) in the AJCC 8, has been criticised for its lack of homogeneity and distinctiveness, with no difference in survival between pT2 and pT3 tumours, nor between stage III and stage IV disease. The nodal staging system is likewise a poor predictor of patient outcomes. In addition, the AJCC8 staging system for cutaneous SCC is similar to that of mucosal SCC, despite the vastly different biological behaviour of these diseases. Aim: To understand the experience of head and neck cancer surgeons, pathologists, radiation and medical oncologists in using the AJCC8 in routine management of HNcSCC patients. Method: A literature review was undertaken to: (1) determine the prognostic utility of HNcSCC AJCC8 staging system, (2) identify tumour factors which may influence the staging system, and (3) identify avenues to improve the staging system. An eighteen-part online questionnaire was administered to surgeons, surgical pathologists, oncologists, and radiation oncologists, designed to elicit their views on the prognostic utility of this staging system. Results and discussion: Literature review using the terms ‘head and neck’, ‘cutaneous SCC’, ‘prognosis’ and ‘AJCC’ yielded over 200 results pertaining to the prognostic features of HNcSCC, with fewer than 20 peer-reviewed, indexed manuscripts directly relevant to the prognostic performance of the AJCC8 HNcSCC staging system. The evidence suggests that the omission of prognostically important characteristics (such as patient immunosuppression, depth of invasion, perineural invasion, extent of extranodal extension, and soft-tissue metastases) may contribute to the poor predictive performance of the staging system. The questionnaire is being currently circulated and the Results will be provided.