Cancer in the heart can lead to shortness of breath, fainting, and other symptoms. Cancer can start in the heart, for instance, after radiation exposure. But it is more likely to spread to the heart from elsewhere. Treatment and outlook will depend on where the cancer started.

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Heart cancer is not among the most common types of cancer, but it can be difficult to detect because it can produce nonspecific symptoms or be asymptomatic.

This article provides more information about heart cancer, including its prevalence, symptoms, risk factors, diagnosis, and treatment. It also explains how to reduce the risk of heart cancer and considers the outlook for people with the condition.

Primary cardiac tumors are heart tumors that originate within the heart. They are rare, affecting between 0.001% and 0.3% of the general population. Moreover, only 10% of primary cardiac tumors are cancerous.

Secondary cardiac tumors, which doctors may call cardiac metastases, are heart tumors originating from other forms of cancer. These heart tumors are always cancerous and affect about 0.4% of the general population.

However, the authors of a 2020 review report that in people with an existing cancer diagnosis, the likelihood of cancer spreading to the heart can reach 12%. They also note that secondary cardiac tumors are 20–40 times more common than cancerous primary cardiac tumors.

Heart cancer is not always symptomatic, so a person may not experience symptoms. They may remain unaware of the condition.

However, heart tumors do sometimes interfere with heart function. In some cases, they can lead to a variety of symptoms, such as:

It is worth noting that noncancerous heart tumors can also cause these symptoms.

When to consult a doctor

Anyone with any of the above symptoms should promptly seek medical advice to help determine what may be causing them.

Many heart cancer symptoms are nonspecific, meaning other conditions can produce similar symptoms.

Regardless of the underlying cause, an earlier diagnosis may increase the likelihood of effective treatment.

The possible causes of heart tumors depend on whether they are primary or secondary tumors.

Scientists remain uncertain about the exact causes of primary cardiac tumors. However, there is evidence that some people have a genetic predisposition. Other risk factors for primary cardiac tumors include:

  • tuberous sclerosis
  • Gorlin syndrome
  • Carney complex
  • a family history of cardiac tumors
  • mutations in certain genes, such as:
    • MDM2
    • PDGFRA
    • CDKN2A

Other risk factors slightly increase a person’s chances of malignant heart tumors. These factors include:

  • Age: People ages 50 years and older are more likely to have heart cancer.
  • Sex: Females have a slightly higher chance of heart cancer than males.
  • Race: White people have a higher risk of heart cancer than people belonging to other racial and ethnic groups.

Secondary cancers always originate from cancer that affects another body part. However, some cancers are more likely than others to spread to the heart. These include cancer of the:

Cancers can spread to the heart in several ways. Sometimes, an adjacent tumor grows into the heart. In other cases, the circulatory or lymphatic system is responsible for spreading cancer cells to the heart.

A recent review explains that heart cancer diagnoses will often involve multiple techniques.

Doctors will usually begin with echocardiography. This technique uses ultrasound waves and can detect cardiac tumors 90% of the time.

A different imaging technique is cardiovascular magnetic resonance. This technology uses radio waves and magnetic fields to produce detailed cardiovascular system images. It is especially useful when doctors plan to remove a cardiac tumor surgically.

PET scans and CT scans provide an accurate evaluation of cardiac masses.

Doctors cannot usually determine whether a heart tumor is cancerous unless they first surgically remove some of it. After doing so, they can send the sample for laboratory testing, known as a biopsy.

If there is fluid around the heart, doctors can drain it and test it for cancer cells. This is called pericardiocentesis.

The treatment for heart cancer depends on whether it is primary or secondary.

With primary heart cancer, the best option is often the surgical removal of as much of the tumor as possible. In some cases, doctors may recommend chemotherapy before or after the surgery.

The precise treatment for secondary heart cancer varies depending on cancer’s original location. However, doctors typically use systematic chemotherapy at some point in the process. Systemic chemotherapy is when anticancer drugs use the blood to travel to multiple body parts.

Primary heart cancers are very difficult to prevent due to genetic factors.

Some people are more likely to develop primary heart cancer after radiation exposure. However, it is not always possible to avoid radiation exposure.

Preventing secondary heart cancer may be somewhat easier, as many cancer risk factors are potentially controllable. A 2018 study suggests that individuals can reduce their cancer risk by making certain lifestyle choices. These include:

  • quitting smoking, if applicable, or avoiding secondhand smoke
  • reaching or maintaining a moderate body weight
  • exercising regularly
  • refraining from drinking alcohol

However, it is important to note that these lifestyle choices cannot eliminate the risk of developing secondary heart cancer.

The outlook for people with heart cancer depends on many factors. However, in most cases, there is only a small chance of surviving for 1 year after diagnosis.

The effectiveness of the treatment will also affect the outlook of people with heart cancer. For instance, when doctors can completely remove heart tumors, the average survival rate is 15–17 months. This compares with an average survival rate of 5–6 months among those not eligible for this surgery.

Heart cancers can begin both within and outside of the heart. The likelihood of developing heart cancer will depend on where it begins. The disease may not always produce symptoms, and when it does, it may be nonspecific. As a result, the diagnosis typically involves several diagnostic techniques.

Heart cancer’s origin can significantly affect the treatment options and a person’s likely outlook.