Surgical Excision Versus Mohs Micrographic Surgery for Basal Cell Carcinoma of the Face

Compare Recurrence Rates, Cosmetic Outcomes, and Costs to Choose the Right Procedure.

Facial basal cell carcinoma can be treated with surgical excision or Mohs surgery. Surgical excision involves a surgeon cutting out the tumor along with a border of healthy tissue. In contrast, Mohs surgery removes the tumor in thin layers, which are immediately checked under a microscope to see if any cancer cells remain. 

Studies show surgical excision may have a recurrence rate of 5-10%, while Mohs surgery typically results in a lower recurrence rate, around 1-3%. Doctors often recommend Mohs surgery for larger tumors, high-risk tumors, or tumors located in sensitive areas of the face because it allows for more precise removal and better preservation of healthy tissue. You can find more in-depth information about each procedure below.

What Is Surgical Excision?

Surgical excision is a procedure used to remove a tumor. It involves cutting out the tumor along with a margin of healthy-looking skin using a scalpel. The size of this margin is determined by the surgeons before surgery, based on the tumor's size and location.

After surgery, the tissue is sent to a pathologist for examination. The pathologist examines the tissue microscopically to confirm that the tumor has been completely removed. The presence of clear margins indicates a successful removal. In approximately 5-10% of cases, the margins may be unclear, which means further surgery may be required. This can delay treatment and increase anxiety for the patient while waiting for results.

Long-term follow-up appointments are important for patients who have undergone surgical excision. These appointments help monitor for recurrence of the tumor, which occurs in about 1-3% of cases, depending on the type and stage of the tumor. Regular check-ups are critical for detecting any new or returning cancerous growths early. This early detection significantly improves long-term outcomes and allows for prompt treatment to reduce the risk of complications. Studies have shown that early detection plays a crucial role in improving the prognosis for patients.

What Is Mohs Micrographic Surgery?

Mohs micrographic surgery differs from standard surgical excision by providing immediate margin assessment instead of sending tissue samples to a lab. This technique completely removes tumors while preserving healthy tissue.

The process of Mohs micrographic surgery involves excising a thin layer of tissue first. Following this, technicians process and examine the tissue under a microscope on-site. Should cancer cells persist, the surgeon proceeds to remove another layer of tissue, targeting only the affected areas.

This process is repeated until microscopic examination indicates the absence of any remaining cancer cells. The depth of tissue analysis through Mohs surgery is thorough, enabling precise identification of cancerous roots.

The duration of Mohs surgery can vary depending on tumor size and complexity. Some cases may require multiple stages. This method ensures complete margin control, significantly decreasing the risk of cancer recurrence—possibly to as much as 99% for certain types of skin cancers. This level of precision also maximizes the preservation of surrounding healthy tissue.

Efficacy Comparison

Surgical excision and Mohs surgery both treat basal cell carcinoma, but their success rates differ.

Mohs surgery provides complete margin control during the procedure. Surgeons examine each layer of tissue to ensure full tumor removal while preserving healthy tissue. The recurrence rates for Mohs surgery are notably low, ranging from 1% to 3% for primary basal cell carcinomas.

In contrast, surgical excision involves the removal of a set amount of tissue around the tumor. Since surgeons cannot inspect the edges during the surgery, this approach can result in the removal of extra healthy tissue. Recurrence rates for surgical excision can be higher, potentially between 5% and 10% for similar tumors.

Brush margin analysis can be applied to surgical excision to check margins post-surgery, but this method is not as accurate as Mohs surgery. In terms of cost, Mohs surgery might initially be more expensive. However, due to lower recurrence rates, it could save money in the long term by minimizing the need for additional treatments. For instance, a study highlighted that although the initial cost of Mohs was about 15% higher, overall costs were reduced within five years due to fewer re-excisions. These cost estimates may vary based on individual patient factors and the specifics of the tumor.

Recurrence Rates

Tumor recurrence is a crucial consideration in treatment planning. Mohs micrographic surgery (MMS) is recognized for achieving lower recurrence rates for basal cell carcinoma (BCC), particularly in high-risk areas such as the face, compared to traditional surgical excision.

Recurrence rates differ based on several factors, including tumor characteristics, location, and the duration of patient follow-up. Research indicates that while surgical excision may exhibit a recurrence rate around 10% for certain BCC cases, Mohs micrographic surgery can bring this rate down to 1% or less in comparable scenarios. This is especially true for aggressive BCC subtypes where MMS superior margin control is beneficial.

When planning treatment, consider the following points:

Published recurrence rates provide essential data on the effectiveness of different treatment methods.

Patient age is a significant factor influencing recurrence risk. Younger patients are at a higher risk due to the extended period over which tumor recurrence could occur.

From a cost-effectiveness perspective, while MMS has higher initial expenses compared to conventional surgery, the reduced likelihood of recurrence and subsequent treatments could make it a more economical choice in the long run. This cost-effectiveness varies based on individual case specifics.

Incomplete excision significantly increases the risk of recurrence. Often, close margins following standard excision necessitate additional surgery. Unlike standard excision, MMS provides precise margin control, which reduces the likelihood of leftover cancerous cells.

Although MMS offers improved outcomes with narrower margins, it's important to acknowledge that it's not without risks. Recurrence following MMS, though less probable, is not impossible. Comparatively, the risk remains much lower than with standard surgical excision alone.

Cosmetic Outcomes

Cosmetic results are a significant consideration in choosing a treatment beyond merely preventing recurrence. Mohs surgery tends to create smaller wounds as it meticulously removes tissue only until the edges are clear of tumor. Conversely, surgical excision usually removes a broader margin of tissue to ensure complete removal of the tumor, often resulting in larger wounds.

The method of closure after surgery also significantly impacts the appearance of the healing area. Both Mohs and excision surgeries can employ direct closure, flap reconstruction, or skin grafting. The choice of reconstruction method, along with the surgeon's expertise, primarily determines the aesthetic outcome. For instance, studies have indicated that flaps might provide better cosmetic results than grafts in specific facial areas.

When considering healing time, it's important to note that Mohs surgery may allow for faster initial healing due to smaller defect sizes. However, complex reconstructions following either Mohs or excision can prolong the healing process. Generally, simple, straight-line closures heal quicker than skin grafts. While healing times can differ, a study highlighted that simple closures often heal within 2-3 weeks. In contrast, some grafted areas may take 4-6 weeks to fully heal. Ultimately, the optimal treatment choice involves a balance between effective tumor removal, cosmetic outcome, and healing time, tailored to the individual's specific situation.

Complications

Even with skilled surgery, complications can happen after Mohs surgery or surgical excision. Discomfort is expected and can often be managed with over-the-counter pain relievers. However, in some cases, stronger medication might be necessary. Infection is a possible risk, but employing proper wound care can significantly reduce this chance. Studies indicate that consistent wound care reduces infection rates by about 30%.

Potential Problems to Watch For:

• Bleeding/Hematoma: Pressure or further treatment may be required.
• Infection: Symptoms include increased pain, redness, and drainage. Infection rates are approximately 1-5% depending on the location and patient health.
• Scarring: Some level of scarring is expected after any skin surgery.

Poor suturing techniques increase the risk of wound separation (dehiscence) or noticeable scars. Nerve damage, though rare, can result in temporary or permanent numbness, occurring in less than 2% of cases. It's important to remember that cancer can recur even after complete removal. Regular follow-up appointments allow for early detection and swift treatment. Reporting any signs of swelling, increased pain, or unusual discomfort is crucial.

Ideal Candidates for Each Procedure

Choosing between Mohs surgery and surgical excision depends on the tumor's size and location, as well as your individual needs. Surgical excision often works well for basal cell carcinomas smaller than 2 cm. 

Doctors often choose it when the tumor has clear, well-defined edges and is in an area with plenty of extra skin. Surgical excision may be a good choice when your medical goals are as important as how it will look afterward, and you can schedule the surgery instead of needing it immediately.

Factor	Surgical Excision	Mohs Surgery
Tumor Size	Small, under 2 cm	Larger, over 2 cm
Location	Areas with enough extra skin	Areas where saving skin is very important
Tumor Borders	Well-defined edges. Not a good choice if unclear	Unclear edges or tumors that have come back

Mohs surgery often works better for tumors on the nose, eyelids, or lips, where appearance matters a lot. You might also be a good candidate for Mohs if the tumor has returned, is large, or has unclear edges. Mohs surgery is best when saving as much healthy tissue as possible is essential, and complete tumor removal is vital during a scheduled, not emergency, procedure, prioritizing both medical and cosmetic results.

Making the Right Choice

Choosing the best treatment for a tumor involves careful consideration of multiple factors. Key aspects to evaluate include the benefits and drawbacks of surgical excision — which involves cutting out the tumor — and Mohs micrographic surgery — a technique that removes the tumor layer by layer. Factors such as the tumor's location, size, type, and the patient's overall health significantly influence the decision of which treatment is most suitable.

When considering treatment options, recurrence risk is a major factor. Mohs surgery is often associated with lower recurrence rates, particularly for tumors with a high probability of coming back. For instance, studies indicate that Mohs surgery could cut the recurrence rate of certain high-risk skin cancers nearly in half compared to standard surgical excision.

Another important aspect is the preservation of healthy tissue. Mohs surgery is advantageous in this regard as it spares as much healthy tissue as possible, which is particularly crucial in areas where maintaining appearance is important, such as the face. By contrast, standard surgical excision might remove wider margins of tissue which can include healthy tissue, potentially affecting function or appearance.

The procedural time varies between the two treatments. Standard surgical excision can be more swift for straightforward cases. On the other hand, Mohs surgery is more time-consuming as it comprises multiple stages, including immediate tissue analysis in a lab.

While surgery and radiation can be considered in certain circumstances, they are less frequently chosen. Additionally, cost is an essential factor to consider. The costs associated with surgical procedures, laboratory fees, and any subsequent reconstructive surgery can vary. Initially, Mohs surgery might appear costlier. However, this view should be balanced against the potential long-term expenses incurred by a possible tumor recurrence necessitating additional treatments. An informed decision should be reached through a collaborative effort between a qualified surgeon and a well-informed patient.