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.

Dr Richard Quek​, Deputy Head and Senior Consultant, Division of Medical Oncology, National Cancer Centre Singapore (NCCS), a member of the SingHealth group, said: "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. The 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 patients 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. Many doctors may not even encounter a single case throughout their careers," said Dr Quek.

Symptoms of heart failure

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 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," said Dr Quek.

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.

Read on to learn about heart cancer treatment options​.​

Ref: R14