Yes, skin cancer can come back after Mohs surgery, but it is uncommon. When it does return, it usually grows at or near the scar, most often in the first few years after treatment. Most recurrences are picked up at follow-up appointments or because the patient notices a change, and they can still be treated, often with Mohs surgery again.
- Recurrence means the original cancer has grown back at or near the treated site. A new skin cancer somewhere else is a separate problem.
- Mohs checks the edges of the removed tissue under a microscope during the operation, but no technique brings the risk to zero.
- The risk is higher for cancers on the face, large or aggressive tumours, cancers that have come back before, and people with a weakened immune system.
- If you notice a lump, sore or change near your scar, contact your specialist rather than waiting for your next appointment.
What does skin cancer recurrence mean?
Recurrence means the cancer has come back after treatment. For basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), it usually means new growth at or very close to the site of the original surgery. A new skin cancer elsewhere on your body is not a recurrence, though you should watch for that too.
- Local recurrence: the cancer grows back at or right next to the original site, usually because a few cancer cells survived treatment.
- Regional or distant recurrence: cancer cells spread to nearby lymph nodes or, rarely, to other organs. This is much less common with BCC and SCC, but it is a recognised risk with more aggressive tumour types.
A clear margin report is very good news, but it describes the tissue at the moment it was removed. Occasionally, tiny clusters of cells sit just beyond the tissue that was taken, or deeper than the surgery reached. That is why the idea that Mohs is an absolute guarantee is one of the common Mohs myths.
How common is recurrence after Mohs surgery?
It is uncommon. The surgeon removes the cancer in thin layers and examines each one under a microscope, carrying on until no cancer cells are left at the edges. Because every edge is checked, recurrence after Mohs is uncommon for basal cell and squamous cell carcinomas, though no treatment can rule it out completely.
The risk is lowest for a cancer being treated for the first time, and higher when it has already come back after earlier treatment. You can read more about how Mohs works if you want the detail.
Who is more likely to have cancer come back?
Some people and some tumours carry a higher risk than others, and knowing where you stand helps you and your specialist decide how closely to watch.
- Tumour location: cancers on the face, especially around the nose, eyes, ears and lips, sit in complicated areas where complete removal is harder. This is one reason Mohs for facial cancers is often recommended.
- Tumour size: larger tumours, particularly those over 2cm, are more likely to come back, partly because they may have sent microscopic extensions into the surrounding tissue.
- Tumour type: morphoeic BCC (also called infiltrative or sclerosing) and poorly differentiated SCC behave more aggressively and are harder to clear completely, even with Mohs.
- Earlier surgery with narrow margins: if a cancer was previously removed by standard surgical excision and the margins were narrow or uncertain, some cells may have been left behind.
- Previous recurrence: a cancer that has already come back once is harder to treat and more likely to come back again.
- A weakened immune system: people taking long-term immunosuppressant medicine after an organ transplant, people living with HIV and people having chemotherapy have a higher risk of both recurrence and new skin cancers. Their immune system is less able to find and destroy stray cancer cells.
If you are immunosuppressed, or your cancer was on a sensitive area of the face, ask your specialist whether you need a follow-up plan tailored to you rather than the standard schedule.
Signs to look for around your scar
Check the scar and the skin around it every so often. Look for:
- a new lump, bump or thickening in or around the scar
- redness, scaling or crusting that hasn’t settled within three to four weeks
- a sore that bleeds easily or won’t heal
- parts of the scar that feel unusually firm or irregular
- itching, burning or tenderness at the site with no obvious cause
If you notice any of these, contact your specialist promptly rather than waiting for your next booked appointment. A recurrence found early usually needs smaller, simpler treatment, and that makes the most difference on the face. Our recovery tips cover what to look after at home between visits.
What happens if skin cancer comes back?
Your specialist will examine the area and usually take a biopsy, a small sample of tissue checked under the microscope. The result confirms whether the cancer has returned and what type it is, which shapes the treatment plan. Our guide to follow-up after treatment explains what happens at these appointments.
Treatment options include:
- Repeat Mohs surgery: the first choice for most recurrent BCCs and SCCs, especially on the face and other complex sites.
- Wide local excision: an option for cancers in less sensitive areas, with the margins checked carefully under the microscope.
- Radiotherapy: used when surgery isn’t suitable, either because of a person’s general health or because more surgery would cause too much loss of function.
- Drug treatments: for advanced SCC, an immunotherapy drug such as cemiplimab may be used. For advanced BCC that isn’t suitable for surgery or radiotherapy, there are medicines called hedgehog pathway inhibitors.
Coping with a recurrence
Many people feel shocked, frustrated or anxious when cancer comes back, even if they knew it was possible. Those feelings are normal, and recurrences found early are usually very treatable. Talk openly with your care team about how you feel, and see our guide to practical support for you and the people around you.
Why keep going to follow-up appointments?
They are the most reliable way to catch a recurrence while it is still small. After a clear margin report, many people want to put the whole experience behind them, but skipping reviews is how an early recurrence becomes a larger one. If you have had a basal cell carcinoma removed, our basal cell removal guide explains what treatment and aftercare involve.
Talking to Miss Nayar
Miss Rakhee Nayar is a Consultant Plastic Surgeon, FRCS (Plast), MD, and one of fewer than 10 women in the UK dual-trained in both plastic surgery and Mohs micrographic surgery, with over 20 years of surgical experience. She sees patients with newly diagnosed skin cancers and patients whose cancer has come back, including people needing Mohs surgery for BCC. If you are worried about a change near an old scar, you can book a consultation.
Frequently asked questions
How do I know if my skin cancer has come back?
You may notice a new lump, a sore that won’t heal, redness or crusting that doesn’t settle, or a change in how the scar feels. Contact your specialist promptly if you do. A biopsy confirms whether it is a recurrence.
What is the chance of recurrence after Mohs surgery?
The chance is low. Recurrence after Mohs surgery is uncommon, and most recurrences are found at follow-up. The risk is higher for cancers that have come back before, large or aggressive tumours, cancers on the face and people with a weakened immune system.
How soon does recurrence usually happen?
Most recurrences appear within the first few years after treatment. Some appear much later, so keep checking your scar and going to follow-up appointments even after the early years have passed.
Can a recurrence always be treated with Mohs surgery again?
Not always, but repeat Mohs surgery is suitable for most recurrent BCCs and SCCs, particularly on the face. The decision depends on the type of cancer, where it is and what treatment you had before. Radiotherapy or drug treatments are alternatives when surgery isn’t suitable.
Does a recurrence mean my cancer is more dangerous?
Not necessarily. Many recurrences are found early and treated successfully, especially when patients keep their follow-up appointments and report changes promptly.
Recommended
- Why reconstruct after skin cancer? Restore function and confidence
- Expert skin health tips for Mohs surgery recovery
- Surgical excision for skin cancer: treatment & reconstruction
- Reconstruction After Mohs Surgery
Filed under Mohs Surgery
