Mohs surgery is a specialized procedure for removing skin cancer. This technique involves the removal of the cancerous tumor layer by layer, with immediate microscopic examination of the tissue margins while the patient waits. This method offers complete margin control, ensuring all cancer cells are removed while sparing the maximum amount of healthy surrounding tissue. Mohs surgery is most frequently used to treat basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Alternatives are needed when the tumor’s characteristics or the patient’s health status make the procedure less suitable, or when a less invasive option is preferred.
Wide Excision and Traditional Surgical Removal
The most direct surgical alternative to Mohs surgery is standard surgical excision. This procedure involves removing the skin cancer along with a predetermined, fixed margin of healthy tissue, typically 4 to 6 millimeters (mm) for non-melanoma skin cancers. The surgeon removes the entire lesion in a single pass, and the wound is then closed with sutures.
The defining difference from Mohs surgery lies in the margin assessment process. With standard excision, the removed tissue is sent to an external pathology laboratory. Margins are checked using vertical sectioning, meaning only a small fraction (often less than 1%) of the total margin surface is examined microscopically. Results are not available until days later.
If the pathology report indicates cancer cells are still present at the edges (a positive margin), the patient must return for a second surgery. For low-risk tumors on the trunk or limbs, WLE provides cure rates around 95% for primary non-melanoma skin cancers. However, the larger initial margin and delayed confirmation make it less suitable for high-risk tumors or those in cosmetically sensitive areas.
Destructive and Topical Methods
Non-surgical treatments focus on destroying the cancerous tissue in place. These destructive methods include cryotherapy, which uses liquid nitrogen to freeze and kill abnormal cells. The procedure causes the treated area to blister and peel off. It is a quick option for very superficial lesions, with an effectiveness rate of over 85% for conditions like actinic keratoses.
Another common approach is curettage and electrodessication (ED&C). A sharp, spoon-shaped instrument called a curette scrapes away the tumor. This scraping is followed by applying an electrical current to the wound base, which cauterizes the tissue to destroy remaining cancer cells and control bleeding. ED&C is generally reserved for low-risk, superficial basal cell and squamous cell carcinomas, often resulting in a small, flat white scar.
Topical therapies involve applying medicated creams directly to the lesion, offering a non-invasive option for superficial tumors. The chemotherapy cream 5-fluorouracil (5-FU) interferes with DNA synthesis, causing cancer cells to die. Immunomodulator creams, such as imiquimod, stimulate the body’s immune system to attack and clear the cancer cells. The primary limitation of these methods is the lack of tissue confirmation; since no tissue is sent to a lab, there is no microscopic verification that the entire tumor has been eradicated, which can lead to a higher recurrence risk for more complex lesions.
Radiation Therapy
Radiation therapy utilizes high-energy beams, typically low-energy X-rays, to damage the DNA of cancer cells and destroy them. This treatment is often delivered as superficial radiation therapy (SRT), which targets the affected area just below the skin’s surface, minimizing exposure to deeper tissues. Radiation is a viable option for patients who are not suitable candidates for surgery due to advanced age, poor overall health, or medical conditions that make an operation too risky.
The treatment process typically involves multiple, short sessions administered over a few weeks. This approach can achieve high cure rates, sometimes comparable to surgery for early-stage tumors, while potentially offering better cosmetic results in sensitive areas like the face or nose. Assessment of effectiveness is delayed, as there is no immediate confirmation that all cancer cells are gone.
While radiation avoids cutting and stitching, it introduces long-term effects on the skin, such as changes in color, dryness, or thinning of the tissue. For tumors where surgery would result in a significant cosmetic or functional deficit, radiation therapy is a highly effective primary treatment choice.
Factors Influencing Treatment Decisions
The choice between Mohs surgery and an alternative depends on assessing the tumor’s characteristics and the patient’s individual circumstances. Tumor location is a key consideration; lesions in high-risk areas, such as the face, ears, hands, or genitals, generally favor Mohs surgery due to its tissue-sparing precision. Mohs is also preferred for tumors that are large, aggressive, have ill-defined borders, or have recurred after previous treatment.
Tumor factors like size, depth, and the specific cancer subtype determine the required treatment. For small, superficial basal cell carcinomas on the trunk, a less invasive option like ED&C or topical therapy may be considered. Patient-specific factors also play a role, including age, the presence of other health conditions, and the ability to tolerate surgery.
A patient’s personal preference regarding downtime, potential scarring, and the number of office visits also influences the final decision. While Mohs surgery remains the standard for high-risk lesions due to its superior margin control and high cure rate of up to 99% for primary BCCs, alternatives are effective options when risk factors are low. The treatment plan balances the desire for the highest cure rate with cosmetic outcomes and patient convenience.