Bevacizumab for the Treatment of Non-Resectable Pseudomyxoma peritonei Associated with Mucinous Ovarian Tumor of Low Malignant Potential – A Comparison of Two Cases

Pseudomyxoma peritonei (PMP) is a rare tumor syndrome that can be diagnosed in association with mucinous ovarian tumors of low malignant potential. Surgical debulking is the primary treatment modality as chemotherapy has generally proven ineffective in this slowly progressive tumor. When patients with PMP are not surgical candidates, there is no effective treatment, and patients will die of progressive disease. We report two patients with PMP with associated mucinous ovarian tumor of low malignant potential treated with Bevacizumab therapy. Both patients demonstrated disease response to single agent Bevacizumab therapy. One patient had a prolonged response while on therapy, remained stable for 6 months when treatment was held, and then after progressing responded to a second course of therapy. We discuss here (1) the clinical features which may predict a better response to Bevacizumab therapy, and (2) evidence for the use of chemotherapy for inoperable PMP. These cases suggest that Bevacizumab may represent a rare effective therapy for patients with inoperable PMP with ovarian involvement and should be considered for clinical trials in this patient population.