JMIR Publications

ABSTRACT

INTRODUCTION. Incidence of keratinocytic cancers is increasing. In New Zealand, surgical treatment of skin cancers is often undertaken in primary care. In the Waikato district, General Practitioners (GPs) are encouraged to confirm the diagnosis via Teledermatology. Histology should confirm clear surgical margins to reduce tumour recurrence. International guidelines recommend lateral margin for BCCs should be ≥ 3 mm and for SCCs should be ≥ 4 mm. OBJECTIVE. To determine lateral and deep margins in keratinocytic cancer excisions performed by GPs (in private) and plastic surgeons (in a private or public setting) after a teledermatologist had confirmed excision was necessary. Demographic, clinical and histological features were recorded. MATERIAL AND METHODS. A retrospective observational cross-sectional study was conducted. The population sample in the dermatology electronic referral database included keratinocyte cancers recommended for excision from March to May 2022. RESULTS. Histological reports showed excision was complete in 186 of 201 confirmed keratinocyte cancers. The lateral margins of resection were involved in 10 and deep margins were involved in 8 tumours. GPs were responsible for all incomplete excisions; 11 of these were on the head and neck. There were 133 basal cell carcinomas (BCCs); 100 were excised by a GP, 3 by a private plastic surgeon and 30 by a public hospital surgeon. 52 BCCs were on the head and neck (GPs 25, hospital plastic surgeon 25, private plastic surgeons 2) and 81 were other sites (GP 75, hospital plastic surgeons 5, private plastic surgeon 1). Lateral margins were involved in 9 cases (5 on head and neck). The minimum distance from the tumour to the lateral margin was < 3 mm in 80 cases where excision was by a GP (64), private plastic surgeon (2) or hospital plastic surgeon (14). It was ≥ 3 mm in 44 cases (27 GPs, 1 private and 16 hospital plastic surgeons). These data showed statistical significance (P=.009) (OR=2,873, IC 1.274–6.477) between GPs and plastic surgeons. There were 68 squamous cell carcinomas (SCCs); 57 were excised by a GP, 2 by a private plastic surgeon and 9 by a public hospital surgeon. 21 SCCs were on the head and neck (GPs 14, hospital plastic surgeons 6, private plastic surgeon 1), and 47 were other sites (GP 43, hospital plastic surgeon 3, private plastic surgeon 1). Lateral margins were involved in one head and neck case, and were not reported in another. The minimum distance from the tumour to the lateral margin was < 4 mm in 35 cases where excision was by a GP (31), private plastic surgeon (1), or hospital plastic surgeon (3). It was ≥ 4 mm in 31 cases (24 GPs, 1 private and 6 hospital plastic surgeons). These data did not show statistical significance (P>.05) between GPs and plastic surgeons. CONCLUSION. Complete resection reduces the risk of recurrence of keratinocytic tumours. GPs in our study were less likely than specialist surgeons to respect surgical margin recommendations established in international guidelines for managing keratinocytic cancer.