The definitive treatment of primary keratinocyte cancer involves complete excision of the skin and subcutaneous tissue – usually fat. Margin-control surgery may be offered to some patients for removing keratinocyte cancers with a high risk of recurrence or metastasis, or to maximise skin preservation (e.g. around the lips, nose or eyes). Curettage and diathermy may be an option for some keratinocyte cancers. Referral to a specialist plastic surgeon may be required.

Most clinically favourable BCCs can be excised with a margin of 2–3 mm, with a very high chance of achieving complete excision and long-term control. While a margin of 0.5 mm may be adequate for a well-defined (nodular) BCC, an aggressive form of BCC would require a wider margin of 3–5 mm.

The recommended surgical margin of excision for SCC varies from 2 mm to 10 mm. For SCCs with poor prognostic features, even wider margins may be necessary (Cancer Council Australia Keratinocyte Cancers Guideline Working Party 2019). If there is any concern about margins, consider a discussion with a pathologist and referring for adjuvant radiotherapy if re-excision is not possible.

Timeframe for starting treatment

Patients will be prioritised depending on their particular tumour type and extent but will usually be having active treatment within a three-month period.

Training and experience required of the surgeon

Surgeons must have training and experience of this standard:

• Fellow of the Royal Australian College of Surgeons or Fellow of the Australasian College of Dermatologists (or equivalent) with adequate training and experience that enables institutional credentialing and agreed scope of practice in keratinocyte cancer
• adequate training and experience that enables institutional credentialing and agreed scope of practice within this area (ACSQHC 2015).

Documented evidence of the surgeon’s training and experience, including their specific (subspecialty) experience with keratinocyte cancer and procedures to be undertaken, should be available.

Health service characteristics

To provide safe and quality care for patients having surgery, health services should have adequate equipment and staff availability appropriate to the complexity of surgery being performed. Critical care support may be required.

Definitive radiation therapy should be recommended for primary keratinocyte cancer in patients who have declined or have contraindications for conventional surgery, and for cases of persistent, recurrent or advanced keratinocyte cancer where adjuvant radiation can complement surgery to improve control rates (Cancer Council Australia Keratinocyte Cancers Guideline Working Party 2019). Radiation therapy is also an important local modality in the palliative setting. Radiation therapy may also be the primary treatment for appropriate histologically proven tumours, usually where other treatment modalities are less appropriate.

For lesions that will be treated by radiotherapy alone, a confirmatory biopsy is advisable.

Clinical scenarios where patients with keratinocyte cancer may benefit from radiation therapy include the following.

Definitive radiation therapy:

• patients unsuitable for surgery
• where surgery creates significant functional and/or aesthetic morbidity that is unacceptable to the patient (e.g. near the lip, eyes or nose).

Adjuvant radiation therapy:

• patients with incompletely excised keratinocyte cancer where re-excision would result in significant morbidity; adjuvant radiation therapy provides comparable control rates to re-excision and may be a good alternative in these scenarios (Cancer Council Australia Keratinocyte Cancers Guideline Working Party 2019)
• patients with locally advanced or node-positive disease
• patients with neurotropic or recurrent lesions.

Symptom palliation:

• bleeding, fungating, rapidly growing or painful skin lesions.

If the excision specimen shows evidence of perineural invasion (PNI) in more than one nerve, in nerves larger than 0.1 mm or evidence of PNI extending away from the main tumour mass, the patient should be referred for an opinion about postoperative radiotherapy because these patients are at higher risk of local recurrence.

Timeframe for starting treatment

Adjuvant radiation therapy should start as soon as possible once the surgical wounds have healed, usually within four to six weeks of surgery.

Training and experience required of the appropriate specialists

The appropriate specialist should be a radiation oncologist (FRANZCR) with adequate training and experience, institutional credentialing and agreed scope of practice in keratinocyte cancer.

The training and experience of the radiation oncologist should be documented.

Health service unit characteristics

To provide safe and quality care for patients having radiation therapy, health services should have these features:

• linear accelerator (LINAC) capable of image-guided radiation therapy (IGRT)
• dedicated CT planning
• access to MRI and PET imaging
• automatic record-verify of all radiation treatments delivered
• a treatment planning system
• trained medical physicists, radiation therapists and nurses with radiation therapy experience
• coordination for combined therapy with systemic therapy, especially where facilities are not co-located
• participation in Australian Clinical Dosimetry Service audits
• an incident management system linked with a quality management system.

The following treatments may be used for SCC in situ (Bowen’s disease or intraepithelial squamous cell carcinoma) and early-stage keratinocyte cancer when surgery is not suitable. The following treatments should be compared with surgery when discussing the likelihood of cure with the patient:

• curettage (with collection of a sample for histopathology) and electrocautery for well-defined, superficial or small nodular primary BCCs, SCC in situ and for selected low-risk SCCs where excision is not feasible
• cryotherapy for SCC in situ and early-stage superficial BCCs
• 5-fluorouracil cream for multiple solar keratoses and SCC in situ
• imiquimod cream for biopsy-proven superficial BCCs, multiple solar keratoses and SCC in situ
• photodynamic therapy for multiple solar keratoses, SCC in situ and selected cases of superficial BCC
• oral acitretin as an antiproliferative agent as chemoprophylaxis for post–solid organ patients with multiple previous SCCs.

Timeframes for starting treatment

Treatment should start as soon as diagnosis and staging has occurred, and the treatment modality becomes available, ideally within four weeks of the MDM.

For patients with locally advanced or a metastatic BCC, hedgehog pathway inhibitors (vismodegib and sonidegib) are currently available targeted treatment options.

Training and experience required of the appropriate specialists

Medical oncologists must have training and experience of this standard:

• Fellow of the Royal Australian College of Physicians (or equivalent)
• adequate training and experience that enables institutional credentialing and agreed scope of practice within this area (ACSQHC 2015).

Cancer nurses should have accredited training in these areas:

• anti-cancer treatment administration
• specialised nursing care for patients undergoing cancer treatments, including side effects and symptom management
• the handling and disposal of cytotoxic waste (ACSQHC 2020).

Systemic therapy should be prepared by a pharmacist whose background includes this experience:

• adequate training in systemic therapy medication, including dosing calculations according to protocols, formulations and/or preparation.

In a setting where no medical oncologist is locally available (e.g. regional or remote areas), some components of less complex therapies may be delivered by a general practitioner or nurse with training and experience that enables credentialing and agreed scope of practice within this area. This should be in accordance with a detailed treatment plan or agreed protocol, and with communication as agreed with the medical oncologist or as clinically required.

The training and experience of the appropriate specialist should be documented.

Health service characteristics

To provide safe and quality care for patients having systemic therapy, health services should have these features:

• a clearly defined path to emergency care and advice after hours
• access to diagnostic pathology including basic haematology and biochemistry, and imaging
• cytotoxic drugs prepared in a pharmacy with appropriate facilities
• occupational health and safety guidelines regarding handling of cytotoxic drugs, including preparation, waste procedures and spill kits (eviQ 2019)
• guidelines and protocols to deliver treatment safely (including dealing with extravasation of drugs)
• coordination for combined therapy with radiation therapy, especially where facilities are not co-located
• appropriate molecular pathology access.

Immune checkpoint inhibitors (PD-1 inhibitors) and targeted EGFR inhibitors have shown promise in treating locally advanced and metastatic SCC (Australian Cancer Society 2019; Chen et al. 2019). This is best done through a multidisciplinary team.

The key principle for precision medicine is prompt and clinically oriented communication and coordination with an accredited laboratory and pathologist. Tissue analysis is integral for access to emerging therapies and, as such, tissue specimens should be treated carefully to enable additional histopathological or molecular diagnostic tests in certain scenarios.