Basal cell carcinoma

Epidemiology
- Technically the most common cancer, but it is often excluded from data due to its low mortality and morbidity
- BCC accounts for 75% of all skin cancer
- Most common skin cancer
Pathology
- Hedgehog pathway is often mutated
- Almost never metastasises, leading to low mortality and morbidity
- May cause local destruction, which may be severe if located on the face
- Types
  - Nodular BCC
  - Superficial BCC
  - Morpheaform BCC
  - Naevoid basal cell carcinoma syndrome
    - Autosomal dominant disease
    - Multiple BCC in young age
    - Bone and neurological malformations
  - +++
Risk factors
- Chronic sun exposure
- Old age
- Skin types I and II
Clinical features
- Pearly papule or nodule
- Rolled border
- Central crater of ulceration
- On sun-exposed skin
  - Usually upper lip/nose area
- Slow growing
Types
- Nodular BCC
  - Most common type
- Superficial BCC
  - On trunk
  - Flat plaque lesion
- Nevoid basal cell carcinoma syndrome
Prognosis
- Virtually never metastasizes
- Locally aggressive
Diagnosis
- Clinical, based on typical symptoms
- Definite (histological) diagnoses often made after surgical excision of suspected lesion
- Full-thickness biopsy -> histology
Treatment
- Surgery
  - Surgical excision with 5 mm safety border
  - Primary treatment is almost all cases
- Radiotherapy
  - If surgery is not an option
- Chemotherapy
  - Only topical (5-FU)
- Alternatives for superficial and small BCCs
  - Cryosurgery
  - Photodynamic therapy
  - Laser ablation
  - Topical chemotherapy
  - Topical imiquimod
- Targeted therapy
  - Vismodegib or sonidegib
    - Hedgehog pathway inhibitors
  - For metastatic BCC or BCC which recurs after surgery
Follow-up
- Physical examination at 3, 6, 12 months
- Sun protection

Squamous cell carcinoma

Epidemiology
- SCC accounts for 18% of all skin cancer
- Second most common skin cancer, after BCC
Risk factors
- Chronic sun exposure
- Transplantation (transplant-related immunosuppression increases the risk 65-fold)
- Precancerous lesions
  - Actinic keratosis
  - Bowen disease (SCC in situ)
  - Leukoplakia
- Radiation
- Chronic scars, ulcers
- Arsenic, tar
Clinical features
- Painless, non-healing, bleeding ulcer or nodule
- Rapid growing
- On sun-exposed areas
  - Face and neck
  - Lower lip
Prognosis
- Low risk of metastasis (5%)
- Worse prognosis in transplant patients
Diagnosis
- Punch biopsy or after surgical excision
Treatment
- Surgery
  - Surgical excision with 5 mm safety border
  - Primary treatment is almost all cases
- Radiotherapy
  - If surgery is not an option
  - As adjuvant therapy if high-risk features are discovered during pathological staging
- Immune therapy
  - For advanced SCC
  - Cemiplimab – anti-PD-1
- Alternatives for superficial and small SCCs
  - Cryosurgery
- Mohs micrographic surgery
- For low-risk, small SCC
  - Cryotherapy
  - Curettage
- For metastasis
  - Chemotherapy
    - Platina
    - 5-FU
  - EGFR inhibitors – cetuximab
  - PD-1 inhibitor – cemeplimab
Follow-up
- Physical examination
- Regional ultrasound
- Chest x-ray
- Abdominal US
- Sun protection