Introduction

If you or a loved one has leiomyosarcoma, you may want to know how surgery can help. You might have questions about how "surgical margins" stop the cancer from coming back. Good news is here: we have clear facts from studies. This article will tell you what surgical margins are and why they are so important. We will also see how they affect your health now and in the years to come.

What is leiomyosarcoma?

Leiomyosarcoma (LMS) is a rare kind of cancer. It starts in the smooth muscle cells of your body. You have these muscles in places like your uterus, blood vessels, stomach, and gut. Because leiomyosarcomas can grow almost anywhere, what you feel can be different based on where the growth is. Sometimes, LMS is detected early when it causes pain,  appears as a lump, or results in bleeding.¹ 

At other times, it can grow without any obvious signs and will only be found incidentally when you have a scan or surgery for some other reason. LMS can grow fast, and it can spread to other parts of your body, like your lungs or liver. That is why it is key to find it and treat it fast.¹

What are surgical margins?

When a doctor takes out a growth, they also take out a small portion of healthy tissue around it. This portion is called the surgical margin. After surgery, a pathologist will look at these edges under a microscope to check if any cancer cells are there.²

If no cancer cells are present on the edge, it is a clear or negative margin. This means all of the growth has been taken out. If cancer cells are on the edge, it is a positive margin, and this indicates that a part of the growth is still there in your body. Clear margins are important for accurate diagnosis and effective treatment. They give you the best chance of preventing cancer from recurring in the same area. 

Do margins affect recurrence?

Many studies show that surgical margins are important, especially when assessing the risk of recurrence after surgery. When a doctor can take out all of the growth with a clean, cancer-free edge, that is called an R0 margin. The chance that the cancer will come back in the same place when this is achieved is much less.³

But, an R1 margin (where a pathologist sees cancer cells on the edge with a microscope) and an R2 margin (where a visible part of the growth is left in the body during surgery) are unfavourable. They are associated with a higher risk of cancer returning, also called local recurrence, meaning the growth is likely to come back at or near the same location.³

What does research show?

Clean edges help keep the cancer away. They lead to a longer time with no disease, called disease-free survival (DFS). People with R1 or R2 margins have a higher risk of cancer coming back, sometimes twice as likely, compared to individuals with R0 margins. Margin status can also affect how long you live. This is particularly true for people who have surgery for leiomyosarcomas in soft parts of the body or deep in the stomach.⁴ 

But margins only form one part of the overall picture. Other factors like where the tumour is, its size, grade (how bad it looks up close), and whether it has spread to distant sites influence the risk of recurrence. So, getting a clear margin is a major goal in surgery, which forms a part of a bigger plan of care that includes follow-up visits and, in some cases, additional treatment approaches.⁵

Does tumour location make a difference?

The location of the tumour in the body has a major impact on how easily it can be removed. It also affects the chance of it coming back after surgery.² Some parts of the body allow a doctor to take out a portion of tissue surrounding the tumour safely. However, in some areas it can be difficult or even impossible to remove the tumour and the surrounding tissue without damaging nearby organs.⁶ Below, we will see how tumour location affects surgical margins and recurrence.

Uterine leiomyosarcoma

Leiomyosarcomas in the uterus are usually found only after surgery, such as when a hysterectomy is done to remove what was thought to be a benign fibroid. In these cases, the finding of a cancer is unexpected, and adequate tissue surrounding the mass may not have been excised.⁷ As a result, the risk of cancer recurrence is quite high, especially if it has already spread to distant organs like the lungs. There are ongoing discussions among experts about whether further surgery can be helpful in these cases. 

Retroperitoneal leiomyosarcoma

This type of LMS grows intensely in the stomach close to important organs like the kidneys, pancreas, gut, and major blood vessels.⁸ The tumour often wraps around or presses on these key organs, making it difficult to achieve a complete excision. Even after difficult but careful surgeries, local recurrence is a common concern in this type of LMS. 

Extremity and trunk leiomyosarcoma

When the tumour is in the arms, legs, chest, or back, there is often more room for the doctor to work. There are fewer major organs nearby, making it easier to get a clear (R0) margin.⁹ These cases tend to have a lower rate of local recurrence and thus have better results. In many cases, radiotherapy is used after surgery to help stop recurrence if the margins are close.

What is the treatment?

Surgery is the primary treatment modality for leiomyosarcoma, and getting clear surgical margins, meaning no cancer cells are left behind, is important.¹⁰ This is one of the best ways to lower the risk of the cancer coming back. Where the tumour is located in the body can make a big difference in how easy it is to remove it completely. Tumours in the arms or legs are usually easier to treat with wide margins, while those in the uterus or deep abdomen are more difficult.¹¹

Can other treatments help?

In some cases, doctors may use other treatments alongside surgery to reduce the risk of cancer coming back. These are called adjuvant therapies, and they’re most commonly used when the tumour is hard to remove completely or when the surgical margins are close or positive.¹²

Radiotherapy (Radiation therapy)

Radiotherapy uses focused beams of energy (like X-rays) to kill cancer cells. It is often used after surgery to reduce the risk of local recurrence, especially if the tumour was in the limbs or trunk and the margin was close.¹³

Radiation is not painful and is usually given over several sessions. It is also helpful when the tumour can’t be removed with a wide margin. In retroperitoneal LMS, radiation is sometimes given before surgery to shrink the tumour and make it easier to remove.

Chemotherapy

Chemotherapy involves using drugs that travel through the bloodstream to target cancer cells. While it is often used in other types of cancer, it  is less effective for leiomyosarcoma when used to prevent recurrence.¹⁴

Chemotherapy may be recommended if the cancer has spread or is considered high-grade (fast-growing). However, it is not typically used after surgery unless there is a high risk of recurrence or distant spread. Some patients take part in clinical trials to access new combinations of chemotherapy or targeted therapies.

Emerging approaches

Researchers are developing new tools to help improve outcomes in leiomyosarcoma:

• Intraoperative imaging (like real-time MRI or fluorescence) helps surgeons see more clearly and identify tumour tissue separately from healthy tissue during the operation, reducing the chance of leaving out tumour tissue
• Molecular profiling of the tumour may help identify patients at higher risk of recurrence or who might respond to new treatments
• Multidisciplinary care teams, with the collaboration of surgeons, oncologists, radiologists, and pathologists, can better plan complex surgeries and coordinate follow-up care to improve patient outcomes

FAQs

Can leiomyosarcoma come back even with clear margins? 

Yes, it can. Leiomyosarcoma is an aggressive type of cancer. It can come back even after a successful surgery. But the risk is less when you have clear margins.

What happens if the surgeon can’t get clear margins? 

At times, it is not possible or safe to take out all of the tumour. This can be when it is near a vital organ or system. If this is the case, doctors may use other care, like radiation therapy. This is to make it less likely to come back.

Is radiation or chemotherapy always used after surgery? 

Not all the time. Radiation is used at times after surgery if the removal of the entire tumour was difficult. Chemotherapy does not work well for leiomyosarcoma as it does for other types of cancers, and therefore is used only for bad or high-risk cases.

Summary

A surgical margin is the part of tissue all around the tumour that the doctor cuts out together with the tumour. After the surgery, a pathologist will look at this edge under a microscope to look for cancer cells. Clear margins show that all of the tumour was taken out. This makes it less likely the cancer will come back in the same spot. 

Surgery is the primary treatment modality for leiomyosarcoma. When clear margins can’t be achieved, treatments like radiotherapy may help reduce the risk of local recurrence. Chemotherapy is less commonly used but may be considered in some high-risk cases. New surgical tools and personalised care approaches are helping doctors improve outcomes.