Does further treatment need to be done if a histopathology report for a shave biopsy shows invasive epithelial cells (IEC) are clear of margins?

From the Guidelines

Further treatment may still be needed even if a histopathology report shows invasive epithelial cells (IEC) are clear of margins in a shave biopsy. While clear margins are a positive finding, shave biopsies only sample the superficial portion of a lesion, potentially missing deeper invasion. The decision for additional treatment depends on several factors including the type of cancer, its depth, grade, location, and patient-specific risk factors. For skin cancers like basal cell carcinoma in low-risk areas, observation might be sufficient. However, for melanomas, squamous cell carcinomas, or lesions in high-risk areas, additional wide local excision with appropriate margins (typically 0.5-2 cm depending on cancer type and depth) is often recommended to ensure complete removal of any residual cancer cells. According to a study published in the Journal of the National Comprehensive Cancer Network 1, patients diagnosed with melanoma through shave biopsy should not be managed differently from those diagnosed with excisional biopsy, even in the presence of a positive biopsy margin, but this does not necessarily apply to the need for further treatment after clear margins are reported. Key considerations include:

• The type and depth of the cancer
• The location of the lesion
• Patient-specific risk factors
• The potential for residual cancer cells despite clear margins on the shave biopsy. Follow-up surveillance is also important, with skin examinations every 3-12 months based on risk assessment. The limited sampling depth of shave biopsies is the primary reason why further treatment is often necessary despite clear margins on initial pathology.

From the Research

Invasive Epithelial Cells (IEC) Clear of Margins

• If a histopathology report for a shave biopsy shows invasive epithelial cells (IEC) are clear of margins, the need for further treatment depends on various factors, including the type of cancer, its stage, and the patient's overall health 2.
• A study on the clinical impact and accuracy of shave biopsy for initial diagnosis of cutaneous melanoma found that shave biopsy is the most frequent method of diagnosis of cutaneous melanoma, and while it may underestimate true T-stage, there was no difference in need for reoperation due to T-upstaging based on initial biopsy type 2.
• However, another study on the treatment options for melanoma in situ suggests that surgical excision with clear margins is the standard of care, and topical therapies may be problematic due to the risk of unrecognized invasive components 3.

Treatment Options

• The treatment options for IEC clear of margins may include:
  • Surgical excision with clear margins 3
  • Mohs surgery for clinically ill-defined lesions 3
  • Topical therapies, such as imiquimod, although their efficacy is still being studied 4, 5
  • Electrodessication and cryotherapy, in combination with curettage, which have been shown to be effective in treating superficially invasive and in situ squamous cell carcinoma 5

Considerations

• The decision for further treatment should be made on a case-by-case basis, taking into account the individual patient's circumstances and the specific characteristics of the cancer 2, 3.
• It is essential to consult with a healthcare professional to determine the best course of action for each patient.