Treatment and follow-up

Invasive SCCs grow more rapidly than basal cell carcinomas (BCCs), so should be treated as soon as practicable. The treatment of choice is complete surgical excision with a 3 to 5 mm margin.

For a primary invasive SCC where surgery is contraindicated (eg advanced age, comorbidities) or is likely to result in significant morbidity or scarring (eg around the eyes or lips), consider specialist referral for consideration of radiotherapy.

Postoperative adjuvant radiotherapy is recommended for SCCs that have a high risk of metastasis, such as when:

  • margins are positive (ie incomplete excision)
  • histopathology shows poor differentiation or other high-risk histological subtypes, or perineural or lymphovascular invasion
  • depth of tumour invasion is greater than 4 mm
  • tumour is more than 2 cm in diameter
  • the SCC is recurrent
  • the SCC is in a high-risk site (eg head and neck [especially lip and ear], genitalia).

Metastatic SCCs are treated by a multidisciplinary specialist team that includes surgical, radiation and medical oncologists. Options for systemic therapy of advanced unresectable or metastatic SCCs include immunotherapy (checkpoint inhibitors), targeted therapies (epidermal growth factor receptor–inhibitors) and cytotoxic chemotherapy.

After treatment of a primary SCC, follow-up is recommended to identify local recurrence, metastases and new primary skin cancers. The recommended follow-up depends on patient risk factors (eg immunosuppression, degree of sun damage) and tumour risk factors (eg location on lip or ear, moderately to poorly differentiated). Recurrence is most common in the first two years Cancer Council Australia Keratinocyte Cancers Guideline Working Party, 2019; review the patient every 3 to 6 months after excision for the first 2 years, then every 6 to 12 months. Follow-up should include examination for signs of local, regional and distant metastases (ie surgical scars, regional lymph nodes), and a full skin examination looking for new primary skin cancers. Radiological, biochemical and haematological screening are only indicated if clinical examination shows signs of metastasis.