Central Nervous System Involvement from Epithelial Ovarian Cancer
Ovarian Cancer - Clinical and Therapeutic Perspectives
Introduction Ovarian cancer represents the leading cause of death from gynaecological cancers especially because it relapses in most of the cases. Central nervous system and especially the encephalon are very often involved in metastatic process arising from malignancies coming from many different sites in the whole body. The incidence of brain involvement in metastatic tumours was estimated to be around 25%, that represents a very large proportion and moreover, around 20% of the lesions found
... the lesions found within the central nervous system are diagnosed as secondary locations of a wide spread cancer. The most common tumours that present brain involvement are lung, breast cancers and melanomas, while the gynaecological malignancies contribute around 2% of all the brain metastases, except the trophoblastic diseases that involve the central nervous system in around 30% of the cases. Anyway, although it was believed that central nervous system involvement from epithelial ovarian cancer was very uncommon, it is increasing of incidence. Moreover, the comprehension of how to diagnose and treat these metastases is very important because they are usually characterized, more than the most common liver or lung metastases, by symptomatology that can severely affect the quality of life of these patients. This new finding points out whether or not is appropriate to ask for a brain image technique in the follow up of ovarian cancer patients, and which therapy should these women receive. Today, there are new possible therapeutic approaches including stereotactic radiosurgery, the administration of new effective and with less side effect chemotherapy agents, moreover the improvement in the neurosurgery techniques makes craniotomy from brain metastases a less riskful procedure with better outcomes. Aim of his chapter is to analyse the clinicopathological features of these patients, the diagnosis and the different therapeutic approaches based on our experience and on all the series published in literature in the last 15 years. www.intechopen.com Ovarian Cancer -Clinical and Therapeutic Perspectives 88 2. Incidence Central nervous system involvement from ovarian cancer is an uncommon event, but many studies published in literature agree that it is increasing in incidence. (Cormio, 2011a; Cormio 2011b; Pectasides, 2006) The analysis of two reports present in literature about the biological behaviour of ovarian cancer in autopsied patients reveals that 1 out of 158 women with this tumour actually present a brain involvement. (Bergman, 1966; Julian, 1974) In literature, the reported incidence ranges from 0.29 to 4.) In our recent series of 20 patients the incidence estimated was 5%. (Cormio, 2011a) This increased incidence can be the result of three different aspects. First of all the advances in the production and management of the new chemotherapy agents have guaranteed in the last years a prolongment of life of these patients; this increased time allows the tumour to implant and grow in distant sites. Secondly, the improvement of brain image techniques allowed detecting very small lesions. Finally, the use of chemotherapy agents that seem to pass poorly the blood brain barrier results in the growth of cancer cells within the nervous tissue. Ways of spread to the central nervous system Ovarian cancer usually spreads locally into the peritoneal cavity, while the lymphatic and haematogenous route are possible but rare. Distant metastases are found in about 30% of patients and the most common localizations are liver, lungs and pleura. (Cormio, 2003a) The dissemination of the ovarian cancer into the brain seems to occur in three possible way: via the haematogenous spread, by direct invasion of the nervous tissue after bony involvement, or in case of leptomeningeal carcinomatosis, through retrograde lymphatic spread (Pectasides, 2006) The mechanism of meningeal dissemination is still not known, but hypothetically it should be caused by a direct invasions of the liquor through the choroid plexus, by a rupture of the brain lesions into the ventricles or subarachnoid space, or by infiltration either of the small veins in the arachnoid membrane, either of the lymphatic vessels. (Cormio, 2007) .