Cancer very seldom starts in the heart. But when it does, it can be deadly. 

Cancer in the heart is most often a sarcoma, which is a malignant tumour that develops in the bones or soft tissues such as muscles, nerves, fat or blood vessels.

There are about 50 different soft-tissue sarcomas. The more common ones occur as lumps in the arms, thighs, legs, abdomen, head or neck. As a whole, sarcomas represent 1 per cent of all cancers.

The Division of Medical Oncology from National Cancer Centre Singapore (NCCS), a member of the SingHealth group, shares "We see an average of four to five new patients with sarcomas per week at our centre. For sarcomas of the limbs and trunk, patients tend to seek treatment quickly because it's a visible growth."

Unfortunately, sarcomas of the heart are not so obvious. Heart tumours can occur anywhere – on the outside surface, in one or more chambers, or inside the muscle tissue. Heart sarcomas tend to occur in young adults in their 20s to 40s, but thankfully, they are extremely rare.

"We see one to two patients with cardiac sarcomas a year. Even if we were to include sarcomas of the major blood vessels near the heart, the numbers are still very small – about five to seven patients a year," added the NCCS Division of Medical Oncology.

Heart cancer (cardiac sarcoma) prevention

As mentioned, heart cancer (cardiac sarcoma) is extremely rare. Adopting healthy behaviours help to lower risk of both cancer and heart disease. These include:

  • Avoid the use of tobacco - If you are a smoker, quit.

  • Adopt a healthy diet rich in fruits, vegetables and whole grains, and low in unhealthy fats. Reduce consumption of red or processed meat, and drink alcohol in moderation.

  • Maintain a healthy weight and be physically active.

  • Go for regular tests for cancers and heart disease.

Causes and symptoms of heart cancer (cardiac sarcoma)

The cause of most sarcomas is still unknown. It is not yet understood if dietary or lifestyle choices, such as smoking, put people at risk.

What is known is that symptoms vary depending on the location of the sarcoma. 

  • For instance, if tumours arise in the two right chambers of the heart, obstructing blood flow into the heart, patients may experience swelling of the feet, ankles and legs.

  • If a tumour occurs in the muscle tissue of the heart, the heart's ability to pump blood may be affected. Chest pain, shortness of breath, fatigue and heart palpitations are some of the signs that may point to this.

  • Other non-specific symptoms may include fever, weight loss, night sweats and fatigue.

Because patients tend to be young, their bodies are able to compensate for most of these symptoms, and they tend to ignore the symptoms and simply attribute them to tiredness.

But when symptoms go on for too long or become more severe, that's when they consult a doctor. Unfortunately, the sarcomas are pretty large by then. These kinds of tumours also tend to be high grade, meaning they grow fast and cause more damage.

So when young patients consult a doctor for ​symptoms that seem to point to heart failure, alarm bells go off and further investigation is urgently initiated.

Heart cancer (cardiac sarcoma): How to treat

Unlike most other cancers, with heart sarcomas, size is less of a factor when determining treatment.

The more important question is whether the tumour is located in a place that makes it possible to surgically remove it completely. If it is inoperable, then it doesn't matter how small it is. The ideal situation is, of course, if the tumour is small and operable.

Where possible, surgery is done to remove as much of the cancer as possible. The patient will then undergo radiation to kill off any remaining cancerous cells. Chemotherapy may be used instead of radiation if the location of the tumour is not suitable for radiation.

However, because it is the heart that is affected, surgery may not always be possible. The alternative is to use radiation therapy or chemotherapy to try and shrink the tumour, and in doing so, minimise the symptoms.

Risk of cancer spreading (also known as metastatic cancer​)​​

The possibility of the cancer spreading to other areas is another concern. Because blood flows past the cancerous area in t​he heart before going to other parts of the body, chances of the cancer spreading to the lungs are high. 

The cancer may also spread to the bones or liver. This makes heart sarcoma patients poor candidates for heart transplants.

But there is hope: Continuous advancements in surgical techniques, development of more pinpointed, targeted radiation, as well as research into new drugs may help to delay the disease.​

Ref: I23 (ed)

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