The heart, a vital organ, can be affected by cancer. While it is extremely uncommon for cancer to originate in the heart, it is more often impacted by cancer that has spread from other parts of the body.
How Cancer Affects the Heart
Cancer can involve the heart through two primary pathways. The first involves primary cardiac tumors, which are cancerous growths that begin directly within the heart’s own tissues. The second, and significantly more frequent, pathway is through secondary or metastatic cardiac tumors. These occur when cancer cells from a primary tumor located elsewhere in the body travel to and establish new growths in the heart.
Primary Heart Cancers
Primary heart cancers are exceptionally rare. They account for only a small fraction of all cardiac tumors, affecting fewer than 2 out of 100,000 people annually. The most common types of primary malignant heart cancers are sarcomas. These include angiosarcoma, which is the most frequent in adults and often develops in the right atrium or pericardium, and rhabdomyosarcoma, which is more common in infants and children. Other less common types are fibrosarcoma and undifferentiated pleomorphic sarcoma. These tumors are aggressive, and their prognosis without surgical intervention can be poor.
Secondary Heart Cancers
Secondary or metastatic cardiac tumors, which spread from other organs, are considerably more common than primary heart cancers. These metastatic tumors are estimated to be 20 to 40 times more frequent than cancers that originate in the heart. Cancer cells can reach the heart through various routes, including the bloodstream, the lymphatic system, or by direct extension from a nearby tumor.
Many different types of cancer can metastasize to the heart. Common primary cancer sites that frequently spread to the heart include lung cancer, breast cancer, melanoma, lymphoma, leukemia, ovarian, gastric, renal, and pancreatic carcinomas. The pericardium, the sac surrounding the heart, is the most frequently involved site for metastatic tumors, followed by the epicardium and myocardium.
Recognizing Potential Indicators
Heart tumor symptoms are often non-specific and can resemble those of more common heart conditions. These symptoms depend on the tumor’s location, size, and how rapidly it grows. Common signs include shortness of breath (especially during physical activity), chest pain, heart palpitations or an irregular heartbeat, fatigue, dizziness, and fainting.
Fluid accumulation around the heart, known as pericardial effusion, is another potential indicator, which can lead to increased pressure on the heart and affect its ability to pump blood. Swelling in the legs and abdomen, or other signs of heart failure, can also develop. Less common systemic symptoms like fever, chills, night sweats, and unexplained weight loss may also be present, mimicking an infection.
Finding and Managing Heart Tumors
Diagnosis typically begins with an analysis of a patient’s symptoms and health history, followed by advanced imaging techniques. Echocardiography, a non-invasive ultrasound, is often the initial imaging used to detect cardiac masses and assess their size, location, and impact on heart function. To further characterize the tumor and determine its extent, detailed images are obtained using computed tomography (CT) scans and magnetic resonance imaging (MRI). Positron emission tomography (PET) scans can also assess tumor metabolism, which helps in identifying cancerous activity.
For a definitive diagnosis, a biopsy is often necessary, involving the removal of a tissue sample for microscopic examination. Biopsy procedures can be challenging due to the heart’s complex anatomy and the tumor’s location.
Treatment strategies for heart tumors vary widely depending on the type of tumor, its origin (primary or secondary), its stage, and the patient’s overall health. Surgical removal of the tumor may be an option if feasible, particularly for primary tumors. Chemotherapy and radiation therapy are also employed to shrink tumors and manage symptoms. In cases where a cure is not possible, palliative care focuses on relieving symptoms and improving the patient’s quality of life.