A recent case report by Humphrey in the Journal of Urology offers information about a 67-year-old patient found to have a form of prostate cancer known as angiosarcoma of the prostate. (Access to this article is limited to subscribers to the Journal of Urology, and there is no abstract.)
The vast majority of prostate cancers are known as adenocarcinomas, and they originate in epithelial cells (the type of cells that form the basic structure of many glands in the body, like the prostate gland). By contrast, sarcomas develop in tissues that are derived from embryonic mesoderm.
All primary sarcomas of the prostate are rare. Only about 1 prostate cancer in every 1,000 is a sarcoma, i.e., about a couple of hundred cases a year here in America.
Angiosarcoma of the prostate is very rare indeed, and develops in endothelial (as opposed to epithelial) cells. The endothelium is the layer of cells that lines the interior surface of blood vessels. According to Humphrey there have only been about eight cases of primary angiosarcoma of the prostate reported in the medical literature, in patients ranging in age from 2 to 60+ years of age. This form of prostate cancer is highly aggressive. It can metastasize rapidly to the lymph nodes, the lungs, the spleen, and the liver. According to Humphrey, most patients with angiosarcoma of the prostate will die from their cancer within just 1 to 6 months after diagnosis.
It is important to distinguish between primary sarcomas of the prostate like this and secondary sarcomas, which can occur about 3 years after radiation therapy. However, such secondary sarcomas are also extremely rare, and only a few are documented in the literature. They are not a significant risk factor for the vast majority of men undergoing radiation therapy for a primary adeonocarcinoma of the prostate.
Filed under: Diagnosis, Living with Prostate Cancer, Risk Tagged: | angiosarcoma, primary, sarcoma
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Hopefully there will be more information available regarding angiosarcoma of the prostate to which we can refer patients that might be diagnosed with this unusual and aggressive form of prostate cancer.
Following my earlier post, checked my files and found that while reviewing an eMedicine report, I came across this URL regarding radiotherapy considered possibly responsible for angiosarcoma. The report is based on treating breast cancer in women. However, with known relationship of breast cancer and prostate cancer, should there be a similar concern for men with prostate cancer treated with radiotherapy?
A lengthy explanation and description of angiosarcoma can be reviewed at this URL.
The apparent, very rare occurrence of secondary (as opposed to primary) angiosarcoma of the prostate after first-line radiation therapy of diagnosed with adenocarcinoma of the prostate is well documented. However, whether such secondary angiosarcomas are real is a more difficult question to answer. The case that Humphrey describes is a perfect example. This patient was initially diagnosed with an adenocarcinoma and was treated with radiation. It was only on pathological examination at autopsy that it became clear that this patient had actually had a primary angiosarcoma. It is worth bearing in mind that angiosarcoma of the prostate is so rare that most pathologists and most urologic surgeons will never see a patient with this form of prostate cacner in their entire working lifetimes.
In 22 years as a pathologist, I have seen one case, it was a consult seen while I was at Johns Hopkins. In 15 years of private practice, not one case. A rare bird indeed.