Prognostic implications of residual tumour volume in stage III ovarian cancer patients undergoing adjuvant cytotoxic chemotherapy

Intraperitoneal Chemotherapy with Mitoxanthrone in Ovarian Cancer

Aims and background

Ovarian carcinoma remains confined to the peritoneal cavity for the greater part of its natural history, so intraperitoneal (IP) administration of chemotherapy could result in greater total drug exposure of the tumor and minimize systemic antiblastic drug side effects. The aim of this study was to evaluate the therapeutic efficacy and toxic effects of intraperitoneal mitoxanthrone in patients affected by ovarian carcinoma with macroscopic absence of disease or minimal residual disease.

Methods

Ten patients were enrolled (stage II and III) who had been previously treated with neoadjuvant systemic chemotherapy (CDDP or CBDCA + CTX) and radical surgery resulting in macroscopic absence of disease or minimal residual disease (<1 cm). Mitoxanthrone (25 mg/m2) was instilled in 2 liters of normal saline every four weeks for 2-4 cycles.

Results

A total of 26 courses was administered; two patients discontinued IP therapy, one for chemoperitonitis and another for bowel perforation requiring catheter removal. Of the 10 patients receiving IP chemotherapy, 7 are alive at 5 years from radical surgery, and 3 had relapses at 13, 14 and 57 months, respectively, from radical surgery.

Conclusions

Intraperitoneal mitoxanthrone appears to be an effective second-line therapy in ovarian cancer; it is well tolerated as far as toxic effects are concerned, allowing cost reduction and improved patient compliance. For those cases requiring a limited number of peritoneal accesses traditional percutaneous systems have a more favorable cost/benefit ratio.

An analysis of ovarian tumor diameter and survival

Residual disease following primary debulking surgery is a recognized prognostic factor in ovarian cancer. Few studies have looked at the effect of initial ovarian tumor diameter on survival. As larger tumors are more likely to be detected by ultrasound, this information may be important in determining a survival benefit in screen-detected cancers. We reviewed the case notes and pathology of 168 consecutive cases of primary debulking surgery in epithelial ovarian cancer. We examined the influence of ovarian tumor diameter on survival and its relationship to CA125 levels and stage. For the purposes of analyses, we divided subjects into two groups: those with tumors < 6 cm and those with tumors > 6 cm. There were significant differences between the groups, with smaller tumors having more advanced stage disease compared to larger tumors (chi23 = 15.7, P = 0.0013) The median survival for tumors less than or equal to 6 cm was 17months (95% confidence interval [95% CI], 12 to 22), while for tumors greater than 6cm, the median survival was 36 months (95% CI, 13 to 59; logrank test = 8.61, P = 0.003). However, stage is also an important predictor of survival, and in a multivariate analysis, tumor size was not found to be an independent prognostic factor. There was no significant difference between the groups for CA125 levels. As larger diameter ovaries are more likely to be detected by ultrasound, it may be that screen-detected ovarian cancers will show a survival benefit simply because they detect a subset of ovarian cancers that are associated with a better prognosis.