What Is Leiomyosarcoma?

Overview

Anyone diagnosed with cancer, or who knows families or friends diagnosed with cancer, will know how difficult and challenging the journey may be. Fortunately, our knowledge of this disease continues to grow as we develop new ways to accurately diagnose cancer and find effective treatments. 

Leiomyosarcoma is a cancer of the smooth muscle cells in our body.¹ Smooth muscles function without us needing to think about it, just like our breathing. They can be found lining your organs, including the stomach, intestines, and blood vessels.² Cancer occurs when cells divide uncontrollably, producing more cells in our body than we need. 

The chances of developing leiomyosarcoma increase with age, most commonly affecting adults. Leiomyosarcoma (LMS) is a rare form of soft tissue sarcoma, affecting 1 in 100,000 people per year.³ Leiomyosarcoma can affect almost any smooth muscle in the body, making it indistinguishable from other possible health conditions. Cancer is not something one should go through alone, it is important to practise self-care and seek support during treatment. 

Types of leiomyosarcoma

A sarcoma is a cancer of the tissues. This can begin in the bone, in the connective tissue, fat, blood vessels, tendons, and ligaments.³ The two most common types of leiomyosarcoma are uterine sarcoma and soft-tissue sarcoma. Symptoms are usually not present in the early stages but they can develop as the cancerous tumour grows and invades the smooth muscles. 

Causes of leiomyosarcoma

Risk Factors 

It is difficult to determine the exact cause of leiomyosarcoma but it is thought to run in families. This is because errors in certain genes that cause the cells to grow out of control can be inherited. 

There’s a wide range of factors that can increase the chances of developing LMS, or any other type of soft-tissue sarcoma. These include:⁴

• A family history of genetic disorders such as:
  • Retinoblastoma – a rare type of eye cancer
  • Neurofibromatosis type 1 – a cancer affecting the nerves in the brain and skin
  • Li-Fraumeni syndrome – inheriting a faulty gene in your cell, which increases your chances of developing cancer
• Exposure to radiotherapy, especially near the pelvic area
• Treatment with tamoxifen, which is a common medication used to treat breast cancer for both men and women. It is possible that the use of tamoxifen can increase the chances of developing uterine leiomyosarcoma. Therefore, it’s important to speak with a doctor if you experience any vaginal bleeding and attend regular pelvic exams ⁴
• Leiomyosarcoma is common amongst the older population 

Signs and symptoms of leiomyosarcoma

Typical signs and symptoms vary widely depending on the individual and where the cancer has spread. Common symptoms include:

• Vaginal, bladder and bowel bleeding 
• Poor appetite
• Weight loss
• Unusual pain in the back, pelvis or abdomen
• A cough that lasts for more than three weeks 
• Shortness of breath 
• Swelling in the legs or abdomen

In the early stages of leiomyosarcoma, these symptoms do not usually occur. Yet, LMS can progress rapidly and invade other organs in your body. Speak to a GP if there are any concerns with your health. 

Diagnosis

Biopsy and Histological Exam 

Leiomyosarcoma can be diagnosed through a biopsy, a medical procedure that takes a small sample of tissue to examine for the presence of cancer cells under a microscope. Early diagnosis of uterine LMS is rare because of how rapidly the cancer progresses. A biopsy is not usually done for a uterine LMS but is taken during a hysterectomy (removal of the uterus).⁴ 

Diagnostic methods and imaging techniques 

33% of patients have leiomyosarcoma that has metastasised (spread to other parts of the body).⁵ If a biopsy confirms the presence of LMS, then further tests are required. An MRI, a CT, or PET scan will be performed to determine the status of the cancer and whether it has spread to other areas of the body. 

Staging of Leiomyosarcoma 

If diagnostic tests confirm LMS, doctors will determine the stage and grade of the cancer in order to choose the right and effective treatments. This will involve looking at the size of the tumour and seeing whether the cancer has spread from the primary site to distant organs. 

The TNM staging determines the size of the tumour (T), whether the cancer has spread to the lymph nodes (N) and if the cancer has spread to distant organs (M). Each of these staging systems is labelled with numbers to assess the severity of the cancer. The lower the number, the less the cancer has spread.⁴

Dealing with emotions upon diagnosis 

It is normal to feel a wide range of emotions upon diagnosis. You may feel angry, frustrated, and upset. Your doctors are here to guide and support you during your treatment. Dealing with LMS can take an extreme toll on your emotional well-being. Talking to loved ones, or to a support group, may help spark conversations with others who may understand the experiences you are going through. 

Important Questions to ask your doctor or healthcare team after you have been diagnosed with LMS:

• What is leiomyosarcoma? 
• What is my diagnosis?
• What are my treatment options?
• Is leiomyosarcoma caused by a genetic condition?

Management and treatment for leiomyosarcoma

Treatment Options 

Finding an effective treatment to shrink the tumour and reduce the chances of the cancer returning is difficult. LMS is an aggressive disease and progresses rapidly. To find an appropriate treatment, a multidisciplinary team (a group of healthcare experts) is gathered to make decisions and work towards a collective goal. 

Surgery

Surgery is typically the first line of treatment for early-stage LMS. It removes the cancer tissues, along with sections of healthy tissues, to ensure all cancer cells are removed. During surgery, doctors will ensure to preserve the normal function and appearance of the body, but it’s possible that you may experience difficulty using the affected body part. 

For uterine LMS, where the cancer is localised in the uterus, a hysterectomy (a surgical procedure to remove the uterus) is recommended.⁴

Radiation Therapy 

Radiation therapy can be used as an additional treatment, along with your primary treatment, to improve the chances of eradicating LMS. Radiation therapy works by using high doses of radiation to kill cancer cells, effectively shrinking the tumour. It’s not recommended for those with uterine LMS as it proves to be ineffective.⁴ 

You may experience some side effects after radiation therapy, such as soreness, nausea and fatigue. This improves within a few weeks after the treatment ends. If the side effects are too severe on your health, it’s important to address these concerns with a doctor. They can prescribe anti-sickness medicine to control your sickness. 

Chemotherapy and targeted therapy 

Patients who have advanced LMS are treated with chemotherapy. Chemotherapy is typically used before surgery to shrink the tumour and make it easier to remove during surgery, but can be used after surgery to reduce the risk of the cancer returning. A combination of docetaxel and gemcitabine are given into a vein. These medications are an effective treatment for metastatic LMS.⁴ 

The most common side effects you may experience with chemotherapy are temporary. These include fatigue, feeling sick and hair loss. 

Targeted therapy targets proteins that control the growth of cancer cells. The use of monoclonal antibodies and cancer growth inhibitors are examples of this treatment strategy. Targeted therapy is usually used after chemotherapy. This is an option for advanced LMS. According to research, in some cases of uterine LMS, the cells of affected patients produce unique proteins or have gene alterations that can be specifically targeted by medications to kill cancer cells or stop their growth.

There are a range of cancer growth inhibitors that can block cancer progression. These include:⁵ 

• Kinase Inhibitors
• TRK Inhibitors 
• PARP Inhibitors

Although temporary, some common side effects of targeted therapy are:⁵

• Feeling tired and weak
• Muscle pain
• A cough
• Dizziness
• Constipation
• Fever 
• Dry skin

Lifestyle and Self-care

Receiving care is unique to everyone and it is a priority to ensure that everyone diagnosed with cancer receives the best possible care. It can be challenging to navigate daily life during treatments. You may feel frustration, anger and depression at any point, whether that is during diagnosis or after treatment. Be kind to yourself and ask for mental health support if you need it. It is important to prioritise self-care to ensure you are as comfortable as possible. This could be doing activities you love, talking to friends and family, joining a support group, talking with a counsellor, and practising mindfulness. 

FAQs

How can I prevent leiomyosarcoma?

It is important to maintain a healthy lifestyle, with a diet consisting of nutritious food and regular exercise to reduce the chances of developing LMS. If you have any concerns with your health, speak to a GP. The sooner cancer is diagnosed, the better the chances of treatment. 

How common is leiomyosarcoma?

Despite LMS being the most common subtype of sarcoma, it roughly affects 1 in 100,000 people yearly, which is rare compared to lung and breast cancer. It commonly affects adults over 50 years old. It is rare in children.¹ 

Who is at risk of leiomyosarcoma?

Those who have a genetic condition (like Li-Fraumeni syndrome) or a family history of cancers are more likely to develop LMS. 

What can I expect if I have leiomyosarcoma?

Upon diagnosis, you should expect to start treatment as soon as possible. The type of treatment depends on the size and location of the cancer. Typical treatment includes radiation therapy, surgery or chemotherapy.

Summary

Leiomyosarcoma is a rare type of cancer that affects the smooth muscles in your body. They are found on the walls of hollow organs, such as the heart and kidney. The uterus and the abdomen are the most common sites of leiomyosarcoma, but the cancer can start anywhere in the body. LMS is aggressive, grows rapidly and can metastasise to other parts of the body, such as the lymph nodes. You may not experience any symptoms of LMS in the early stages. Any unusual changes to your health, like unexplainable weight loss, shortness of breath and swelling, must be discussed with a doctor. The type of treatment depends on the stage of your cancer and whether the cancer has spread to your lymph nodes and other distant organs. Our understanding of cancer treatment in leiomyosarcoma is promising, with targeted therapies being developed to treat advanced leiomyosarcoma.