“Dural metastases” in men with progressive, metastatic CRPC
Posted Oct 06 2010 12:00am
The “ dura mater ” (or more simply the “dura”) is a layer of tissue that surrounds the brain, just inside the actual bones that comprise the skull. “Dural metastases” are foci of metastatic cancer that can (occasionally) occur in patients with very late stage prostate cancer. Because the dura is closely associated with the functioning of the nervous system, certain types of neuropathy in patients with metastatic, castration-resistant prostate cancer (mCRPC) may be an indicator for the presence of dural metastases.
Lawton et al. have noted an increase in the survival of patients with mCRPC in recent years. They associate this with the introduction of docetaxel-based chemotherapy in 2004. This may be one of a number of possible reasons. However, they go on to propose that extended survival of men with mCRPC is likely to be associated with an increase in the incidence of less common forms of prostate cancer metastasis over time. Dural metastases are an example of this type of uncommon metastasis, and should be clearly distinguished from metastases to the bones of the skull.
In their recent paper, Lawton et al. report on 10 cases of dural metastasis in men with mCRPC seen at their clinic between 2003 and 2008. Key characteristics of these patients were as follows:
Their median age at initial diagnosis with prostate cancer was 58 years (range, 52 to 80 years).
Their median PSA at initial diagnosis was 37 ng/dl (range 4.9 to 118 ng/dl).
5/10 men had evident metastasis at the time of initial diagnosis.
They had received between 1 and 13 types of treatment (median 5) prior to the diagnosis of dural metastasis.
They had received between 1 and 3 courses of chemotherapy prior to diagnosis of dural metastasis.
Cranial neuropathies were the most common presenting symptoms of dural metastasis.
8/10 patients received treatment for their dural metastasis, of which radiotherapy was the most common.
Median survival for this group of patients was 6.17 months from diagnosis of dural metastasis (range, < 1 to 15 months).
Cranial neuropathies can include things like facial pain, effects on control of the eyes, paralysis of the eyes, and double vision. However, Lawton et al. suggest that any symptom associated with the central nervous system (CNS) in a man with mCRPC is a possible signal for dural metastasis, and should be appropriately investigated and treated.
As treatment for mCRPC continues to improve, most especially with the potential approval of drugs like abiraterone acetate and MDV3100, the need to be aware of greater risk for such relatively unusual metastases and their symptoms will become a critical component in the management of men with very late stage prostate cancer.
Treatment advances in mCRPC may lead to an increased incidence of previously rare metastatic sites. CNS symptoms in men with mCRPC should prompt evaluation for DM.