Background: High-dose platinum-based regimens can produce responses in patients not responding to standard chemotherapy. As in many ovarian cancer patients the disease remains confined to the peritoneal cavity, intraperitoneal (i.p.) chemotherapy has been applied as an alternative approach to increase drug exposure. The delivery of cytotoxic agents to the peritoneal cavity can lead to high drug concentrations intraperitoneally with less systemic toxicity. This study aimed at evaluating the efficacy and toxicity of high-dose i.p. cisplatin plus etoposide and intravenous sodium thiosulphate protection in ovarian cancer.
Patients and methods: Patients with either a pathologically complete response (pCR) after first-line treatment or with persistent disease after first-line platinum-based chemotherapy or abdominal recurrences were eligible. All intraabdominal lesions had to be < 2 cm at the start of i.p. treatment. The treatment consisted of etoposide 350 mg/m2 i.p. followed by cisplatin 200 mg/m2 i.p. with intravenous sodium thiosulphate (4 g/m2 bolus, followed by 12 g/m2 over six hours) protection. Four courses of i.p. treatment were administered in case of pCR and 6 courses otherwise, at four-weekly intervals.
Results: The study comprised 29 patients, six patients with pCR, 17 patients with persistent disease and six patients with abdominal recurrences. They received a total of 105 courses of treatment (65% of the scheduled number of courses). Twelve patients completed scheduled treatment, illustrating its feasibility. In 17 patients treatment had to be prematurely stopped because of inflow obstruction (seven patients), bowel perforation (two patients), renal toxicity (two patients), neurotoxicity (two patients), or malaise and vomiting (four patients). One patient with bowel perforation died of this complication. Severe nausea and vomiting occurred in 51% of cycles. Leukopenia and thrombopenia grade 3 and 4 occurred in 30% and 6% of cycles, respectively. Ototoxicity of cisplatin was measured by serial tone audiography in 23 patients: only eight patients (35%) showed significant audiographic changes, although none of them developed clinical hearing loss. Fifteen patients were evaluable for response: four pCR, five PR, two SD, four PD. The median duration of freedom from progression was 616 days and the median overall survival 1065 days from the start of treatment.
Conclusions: High-dose i.p. treatment with cisplatin and etoposide can be associated with significant toxicities. Major clinical problems are nausea, vomiting, and the formation of intraabdominal adhesions. Intravenous sodium thiosulphate effectively reduces the systemic toxicity of high-dose cisplatin. The value of high-dose i.p. treatment is uncertain and its routine use cannot be recommended.