Heart cancer

Most heart tumors begin with myxomas, fibromas, rhabdomyomas, and hamartomas, although malignant sarcomas (such as angiosarcoma or cardiac sarcoma) have been known to occur. In a study of 12,487 autopsies performed in Hong Kong seven cardiac tumors were found, most of which were benign.[1] According to Mayo Clinic: "At Mayo Clinic, on average only one case of heart cancer is seen each year."[1] In a study conducted in the Hospital of the Medical University of Vienna 113 primary cardiac tumour cases were identified in a time period of 15 years with 11 being malignant. The mean survival in the latter group of patients was found to be 26.2 ± 9.8 months.[2]

Primary malignant cardiac tumors (PMCTs) are even rarer. The most recent published study about PMCTs used the Surveillance, Epidemiology and End-Results (SEER) Cancer Registry to study 497 patients with PMCTs who were diagnosed during 2000–2001 in the United States. Most cases were angiosarcomas (27.3%) with an incidence of 0.107 per 1,000,000 person-years and Non- Hodgkin's lymphomas [NHL] (26.9%), with an incidence of 0.108 per 1,000,000 person-years. The incidence rate of NHL increased significantly over the study period, but the incidence of cardiac angiosarcomas did not. The overall survival of NHL was found to be significantly better than angiosarcomas.[3]

Another previous study using the Surveillance, Epidemiology and End-Results (SEER) Cancer Registry from 1973 to 2011 found 551 cases of PMCTs, with an incidence of 34 cases per million persons. The study also found that the incidence has doubled over the past four decades. The associated mortality was very high, with only 46% of patients alive after one year. Sarcomas and mesotheliomas had the worst survival, while lymphomas had better survival. When compared with extracardiac tumors, PMCTs had worse survival.[4]

Secondary or metastatic heart tumours are much more common than primary heart tumours, occurring even 100 times more often.[5] Every tumour in theory can metastasize to the heart with the only exception being tumours of the central nervous system.[6] Malignant melanomas frequently metastasize to the heart, and represent the tumour with the highest rate of cardiac metastases (in more than half of cases).[7]

Most of these can be cured if the tumor can be completely removed. When a tumor is very large or there are multiple tumors, removing part of it that is not inside the heart walls can improve or eliminate symptoms. Some types can be followed with yearly echocardiograms instead of surgery if they are no longer causing symptoms.

Because they grow rapidly and invade important heart structures, they can be very difficult to treat. Unfortunately, most are not found until surgical removal is no longer possible. Chemotherapy and radiation therapy are sometimes used to try to slow tumor growth and improve symptoms (palliative care), but frequently they are ineffective for primary heart cancer.

In most cases, patients with heart metastases have advanced tumour disease, with the heart being only one of the many places involved in the generalised tumour spread. At that stage of the disease, the patients will have already undergone extensive chemotherapy, radiation therapy or surgical procedures. Cardiac treatment is usually confined to palliative measures.[6]