Poster Presentation Joint Scientific Meeting of the Australian & NZ Head & Neck Cancer Society & NZ Association of Plastic Surgeons

Recurrence, metastatic rates and possible role for sentinel lymph node biopsy in cutaneous scalp SCC: a five year retrospective study in Waikato, New Zealand (1352)

YinQian (Jason) Low 1 , Conor Ledingham 1 , Cliff Yang 1 , Gemma Tierney 1 , Eric Tan 1 , Yang Gao 2
  1. Plastic and Reconstructive Surgery, Waikato DHB, Hamilton, WAIKATO, New Zealand
  2. Plastic and Reconstructive Surgery, Middlemore Hospital, Auckland, New Zealand

Purpose

To audit the excision margins of cutaneous squamous cell carcinoma (SCC) of scalp correlate them with recurrence and metastatic rates; investigate if there is a role for sentinel lymph node biopsy

Methodology

A search on Waikato DHB histology database on all patients who were recorded as having a histological diagnosis of ‘SCC’ and ‘scalp' was conducted from October 2013 to September 2018.

Only patients with primary cutaneous SCC of the scalp were included in the study.

All cases were divided into different stages based on the American Joint Committee on Cancer 8th Edition and a standard proforma was used for data collection. Relevant statistical tests were conducted on results to investigate for significance.

Results

291 lesions in 229 patients with cutaneous SCC were included in the study.

Average age at time of diagnosis was T1 (75 years), T2 (80 years) and T3 (82 years) (ANOVA p=0.8) and mean follow up 18 months with 9% loss to follow up.

Incomplete or narrow excision margins at first excision was 8% overall.

Regional Metastatic rate for T1 was 6.5% (7/107), T2 9.2% (6/65) and T3 12% (7/57) (t test p=0.06).

T1 has a recurrence rate of 100% for excision margins of less than 1 mm for peripheral margin (7/7) and 40% for deep margins (4/10) (t test p=0.03).

Number needed to treat (NNT) is 20 for T2/T3 in comparison to T1.

Conclusion

Our study suggests that the overall risk of regional metastasis for scalp cutaneous SCC to be low (less than 20%) with sentinel lymph node biopsy not indicated for T2/T3 groups.