What is the management of newly diagnosed squamous cell carcinoma (SCC)?

From the Guidelines

Surgical excision, specifically Mohs micrographic surgery, is the recommended primary treatment for newly diagnosed squamous cell carcinoma (SCC) due to its high cure rate and ability to preserve healthy tissue. The management of SCC involves a multidisciplinary approach, considering tumor characteristics, patient factors, and the potential for recurrence or metastasis 1.

Key Considerations

• Tumor size, depth, location, and differentiation are crucial factors in determining the management approach 1.
• Patient factors, such as immunocompromised status, should be taken into account when choosing a treatment modality 1.
• The risk of local recurrence, perineural spread, and metastasis should be assessed and managed accordingly 1.

Treatment Options

• Mohs micrographic surgery is the preferred treatment for high-risk SCC due to its high cure rate and tissue-sparing capabilities 1.
• Standard surgical excision with 4-6 mm margins may be suitable for smaller, well-defined lesions 1.
• Radiation therapy can be considered for lesions that are not amenable to surgery, typically delivered in fractions over several weeks.
• Topical treatments, such as 5-fluorouracil or imiquimod, may be options for superficial lesions, although they have lower cure rates than surgery.
• Systemic therapy with cemiplimab or pembrolizumab may be necessary for advanced or metastatic disease.

Follow-up and Prevention

• Regular follow-up examinations are essential, typically every 3-6 months for the first two years, then annually thereafter, to monitor for recurrence and new primary lesions 1.
• Patients with a history of SCC have a higher risk of developing additional skin cancers, emphasizing the importance of ongoing surveillance and preventive measures.

From the FDA Drug Label

The efficacy of KEYTRUDA was investigated in KEYNOTE-048 (NCT02358031), a randomized, multicenter, open-label, active-controlled trial conducted in 882 patients with metastatic HNSCC who had not previously received systemic therapy for metastatic disease or with recurrent disease who were considered incurable by local therapies.

Patients were randomized 1:1:1 to one of the following treatment arms: KEYTRUDA 200 mg intravenously every 3 weeks KEYTRUDA 200 mg intravenously every 3 weeks, carboplatin AUC 5 mg/mL/min intravenously every 3 weeks or cisplatin 100 mg/m2 intravenously every 3 weeks, and FU 1000 mg/m2/day as a continuous intravenous infusion over 96 hours every 3 weeks (maximum of 6 cycles of platinum and FU) Cetuximab 400 mg/m2 intravenously as the initial dose then 250 mg/m2 intravenously once weekly, carboplatin AUC 5 mg/mL/min intravenously every 3 weeks or cisplatin 100 mg/m2 intravenously every 3 weeks, and FU 1000 mg/m2/day as a continuous intravenous infusion over 96 hours every 3 weeks (maximum of 6 cycles of platinum and FU)

The management of newly diagnosed squamous cell carcinoma (SCC) may include:

• KEYTRUDA 200 mg intravenously every 3 weeks
• KEYTRUDA 200 mg intravenously every 3 weeks, carboplatin AUC 5 mg/mL/min intravenously every 3 weeks or cisplatin 100 mg/m2 intravenously every 3 weeks, and FU 1000 mg/m2/day as a continuous intravenous infusion over 96 hours every 3 weeks (maximum of 6 cycles of platinum and FU) 2

From the Research

Management of Newly Diagnosed Squamous Cell Carcinoma (SCC)

• The standard of care for SCC is usually surgical, with either excision or Mohs micrographic surgery 3.
• However, surgery may not be ideal for elderly patients with numerous lesions, who are poor surgical candidates or who refuse surgery 3.
• Topical treatments such as 5-fluorouracil (5-FU) and imiquimod have been studied as monotherapies in the treatment of SCC in situ with promising results, but long-term tumor-free survival rates are still less than with surgical management 3.
• A combination of topical 5% imiquimod cream, 2% 5-FU solution, and 0.1% tretinoin cream has been used to effectively treat a small, invasive SCC in a patient who declined surgical treatment 3.

Diagnostic Techniques

• Histopathology and correct surgical excision remain the gold standard for the diagnosis and treatment of SCC 4.
• New diagnostic imaging techniques such as dermoscopy and reflectance confocal microscopy have increased the diagnostic accuracy in terms of early recognition, better differential diagnosis, and noninvasive monitoring of treatments 4.
• PET/CT can be used for initial diagnosis and staging of SCC, providing accurate evaluation of the extent of primary tumors, detection of unknown primary tumor, cervical lymph node status, and distant metastatic spread 5.

Surgical Excision

• Surgical excision remains the gold standard for the management of cutaneous squamous cell cancers (SCC) 6.
• National guidelines for operative radial margins predict 95% oncological clearance with a margin of 4 mm for low-risk and 6 mm for high-risk tumours 6.
• However, despite adherence to recommended surgical margins for cutaneous SCCs, the incomplete excision rate remains higher than expected, with most incomplete excisions being incomplete at the deep margin 6.
• A dual aperture fluorescence ratio approach has been evaluated as a means of improving detection of close surgical margins in oral squamous cell carcinoma resections, showing promising results 7.