14. The role of primary care in the prevention and management of keratinocyte cancer
Medicare payment statistics reveal that in 2018 almost 1,000,000 skin cancers were diagnosed and treated in Australia. The vast majority of these were for keratinocytic cancers (KCs). With the large and increasing skin cancer burden that affects so many Australians, it is imperative that all clinicians acquire the necessary knowledge and skills to diagnose skin cancer. The training in dermatology and skin cancer for medical students is variable, and some graduates will have received no training in skin examination and skin cancer diagnosis. Accordingly, many doctors undertake postgraduate training in skin cancer and there are specific programs available to upskill in this area.
Accessibility and affordability of medical services are important considerations for patients who have the need for skin cancer assessment, which may impact on early diagnosis. Primary care practitioners such as general practitioners (GPs) necessarily play a central role in the diagnosis and management of skin conditions.
Malignant skin neoplasms occur at an estimated rate of 1.1 per 100 encounters in a GP’s caseload. The central position of GPs within the Australian Health System accounts for the fact that they diagnose and manage most suspicious skin lesions in Australia. GPs have been shown to achieve a relatively high accuracy in the clinical diagnosis of KCs, and the use of dermatoscopy has been shown to improve the diagnostic accuracy for melanoma as well as KCs within a primary care skin cancer practice.
Difficulty in managing KCs is ‘due to atypical or unusual presentations as well as a poor understanding of their histological variants’. In addition, there is evidence that among people with basal cell carcinoma (BCC) – at least in northern Australia – infiltrative and micronodular types, which are associated with a high risk of recurrence, occur more frequently on the face and neck, where the likelihood of incomplete excision is increased. This finding highlights the importance of appropriate training and acquisition of skills for GPs.
Whether to treat or refer[edit source]
Treatment decisions are influenced by many factors, including the experience and skills of the doctor of first contact, geographical location, and local facilities, including the availability of radiotherapy services and other specialists such as surgeons and dermatologists.
The most appropriate practitioner to manage uncomplicated primary KCs is the adequately trained GP, who can readily remove most of them by an elliptical excision with an adequate margin and primary closure.
Early presentation and diagnosis facilitate implementation of the recommendations in the guideline . The more experience that the GP acquires, largely from hands-on treatment, the better the management process. There is a wide variation in skills, training and confidence among GPs, with some (particularly rural GPs or those with surgical training) possessing skills to manage more complex skin tumours.
GPs should also be aware of the variety of treatment modalities for KCs, including surgical excision, cryotherapy, curettage, topical therapies, photodynamic therapy and radiotherapy. Each management decision should be tailored to the particular lesion in that particular patient. Generally, however, simple surgical excision with direct closure is the treatment of choice for most skin cancers.
The treating GP should have an adequately equipped treatment room with good lighting and sterile instruments. GPs should be prepared to excise many tumours at first contact, which is both beneficial for the patient and cost-effective for the health system. They should also be skilled to perform basic skin biopsy techniques (punch and shave) to establish a diagnosis where appropriate when KC is suspected.
A review of Medicare data on services provided for excision of skin tumours reveals that, along with dermatologists and plastic surgeons, Australian GPs excise a substantial proportion of these lesions on the face and body; not just tumours less than 10mm diameter, but also including those 10–20mm. A study of skin cancer surgery in Australia from 2001 to 2005 revealed that GPs excise the majority of skin cancers and they are increasingly using skin flaps for repair.
The actual decision to refer for specialist management can be difficult. GPs need to be aware of the limitations of their skills and should be prepared to refer to an appropriate specialist, especially where more complicated repairs are being contemplated.
Tumours requiring experience and care[edit source]
GPs managing KCs need to be aware of:
- the required excision margins for each tumour presentation (see: Surgical treatment)
- tumour-specific factors associated with recurrence of keratinocyte cancers (Table 5)
- the pitfalls of surgical excision at certain anatomical sites
- other risk factors for poor outcomes (see: Prognosis).
- the face – risk of poor cosmetic result and potential nerve damage (e.g. temporal branch of facial nerve)
- the lips – high risk of metastasis of cutaneous squamous cell carcinomas (cSCCs)
- helix of the ear – high risk of metastasis of cSCCs
- the eyelids
- the inner canthus of the eye with close proximity to the nasolacrimal duct
- mid-sternomastoid muscle area (Erb’s Point) where the accessory nerve is superficial
- fingers – risk of functional impairment
- lower leg – potential for poor healing.
Table 5. Tumour-specific factors associated with recurrence of keratinocyte cancers
|Tumour type||Normal risk||High risk|
|Basal cell carcinoma||Nodular subtype
Sclerosing (morphoeic) subtype
|Cutaneous squamous cell carcinoma||In situ subtype
Moderately well-differentiated subtype
Location on area other than head and neck
|Poorly differentiated subtype
Spindle cell subtype
Increasing thickness of the primary tumour
Location on the head and neck (especially the lip and ear) or genitalia
Origin in a burn scar
Indications for referral[edit source]
For specific lesions, it is appropriate to refer to a dermatologist or surgeon, even when the GP is experienced in managing KCs. In many instances it is reassuring for both the patient and their GP to refer a technically difficult problem to an experienced specialist colleague.
GPs should consider referral when any of the following are present or apply:
- uncertainty of diagnosis
- any doubts about appropriate treatment
- larger tumours (BCCs or cSCCs >2cm diameter or cSCC >6mm deep)
- multiple tumours
- tumours in technically difficult sites (e.g. ear, tip of nose or eyelid)
- tumour recurrence despite appropriate treatment
- incomplete excision, (especially when complete excision may be difficult)
- tumours for which the recommended treatment is beyond the skills of the practitioner
- anticipation of difficulty with technique or anatomy (an appropriate colleague should be consulted)
- cSCCs on the lips and ears
- infiltrating or sclerosing (morphoeic) BCCs (particularly those on the nose or around the nasolabial fold, where it may be difficult to determine tumour extent and depth)
- cosmetic concerns (e.g. lesions of the upper chest and upper arms, where keloid scarring is a potential problem)
- cSCC accompanied by palpable regional lymph nodes in head and neck, axilla or groin, suggestive of metastatic spread
- large lesions which may require complicated methods of closure such as grafts and flaps, when the GP is inexperienced in these techniques
- GP unavailable for regular follow-up, especially for a SCC.
All patients treated for KCs, whether by GP or specialist, require follow-up for evidence of recurrence, metastasis and/or any new primary skin cancers. The patient’s GP is ideally placed for such review.
Opportunistic surveillance and case-finding[edit source]
Examination for skin cancer should be considered during the general examination of patients presenting with another medical problem or for a routine examination. Although the majority of cancers appear on sun-exposed areas where they are most clearly visible, it is important to keep in mind that a significant number occur on the trunk and limbs. Accordingly, a total-body skin examination is appropriate for many patients, not only in those identified as being at greater risk due to family history, individual medical history (e.g. immunosuppression or past KCs) and skin type (see: Early detection). Such an examination may be a feature of the annual check-up but is recommended in those with previous KCs and immunosuppression.
Education of GPs[edit source]
The curriculum of all university medical schools should encompass the foundations of knowledge and diagnostic skills in dermatology and skin cancer, including the use of dermoscopy.
General practitioners are at the forefront of screening and diagnosis of skin cancer in Australia. Formal postgraduate education and training in this area of their practice, including the proficient use of dermoscopy, is essential. Clinicians should seek a formal qualification and training through universities and, medical colleges or other accredited educational organisations that offer postgraduate courses in dermoscopy. These skills should be assessable within postgraduate training programs.
Education of the patient[edit source]
An important health promotion and educational task for GPs is to educate their patients about prevention and management of skin cancer. One strategy is to place wall charts and patient education material in the waiting room, as well as providing opportunistic education of patients through preventive advice.
A clear explanation of the tumour, the management plan and the reason for any referral is simple, good and sensible medical care.
Practice Point[edit source]
PP 14.1.1. Uncomplicated small tumours should be removed by an elliptical excision and direct closure.
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