Abstract Number: 221

Ten year follow up in squamous cell carcinoma patients with perineural invasion and involved margins: A retrospective audit of a Queensland cohort

Nikhil Dwivedi, Brian De'Ambrosis, Benedict Panizza, Jessica Witherspoon, Duncan Lambie, Julie Moore, David Whiteman

Meeting: 2023 Dermcoll

Session Information

Date: -

Session Title: Surgery for the general dermatologist

Session Time: -

Aims: To describe patient demographics, tumour and nerve specific characteristics, and outcomes among squamous cell carcinoma (SCC) patients who had perineural invasion (PNI) and involved margins, and compare those who underwent surgery with those who did not.

Methods: A retrospective cohort study in collaboration using data extracted from the Queensland Cancer Repository (QCR). The QCR identified 99 patients histologically diagnosed in Queensland with primary SCC containing PNI from 2009 to 2011 that had positive margins, with 10 years follow-up. Demographic factors, tumour and nerve specific characteristics, survival outcomes, and the use of radiotherapy were reviewed.

Results: Out of 99 patients, 23 (23.2%) had re-excisions. Sites that were most commonly re-excised were the nose (26.1%), ear (21.7%) and face (17.4%), and sites that were most commonly not re-excised were the ear (21.1%), cheek (13.2%) and scalp (11.8%). Patients were grouped into four treatment categories and each category’s recurrence and disease related death rate (DRDR) were reviewed: 34 patients did not have re-excisions and did not undergo radiotherapy (recurrence: 29.4%, DRDR: 29.4%), 11 patients had re-excisions but did not undergo radiotherapy (recurrence: 18.2%, DRDR: 9.1%), 42 patients did not have re-excisions but had radiotherapy (recurrence: 23.8%, DRDR: 35.7%), and 12 patients had re-excisions and radiotherapy (recurrence: 41.7%, DRDR: 58.3%). Tumour baseline characteristics were analysed to ascertain any correlation with outcomes.

Conclusions: While the recurrence rate and DRDR was high across all groups, re-excisions appeared to have a greater benefit than radiotherapy in terms of survival. Tumour characteristics directing therapy, low case numbers and the lack of specific margins in pathological reporting may limit the inferences that can be made from this data. Further research should be conducted to determine the excision margins required and the role of radiotherapy in these high-risk tumours.