PARIS--Physicians should strive to maintain intensive platinum therapy in women with low-volume ovarian cancer, urged William McGuire III, MD, of Emory University. "However, I don't think there's yet data to show that we need to crank doses up to the transplant level in order to improve the outcome," he said at the Fifth International Congress on Anti-Cancer Chemotherapy.
Although high-dose chemotherapy is one of the few options open to patients with recurrent ovarian cancer, the relationship between dose intensity and outcome is not linear in the disease; doses must be raised by as much as 10- to 100-fold to overcome intrinsic drug resistance.
Current Approaches Inadequate?
Dr. McGuire believes that current approaches to augmenting dose intensity in ovarian cancer--autologous transplant and intraperitoneal (IP) therapy--are probably inadequate to the task.
A just completed randomized trial comparing intraperitoneal versus intravenous administration of platinum showed that IP therapy offered an advantage in a very small subset of patients with low-volume disease. "These results may make us all rethink the issue of up-front intraperitoneal therapy," Dr. McGuire said. "As a salvage therapy, we can get complete pathologic responses in 20% to 30% of patients, but how long the responses last is unknown."
While acknowledging that IP therapy offers some theoretical advantages, he warned, "I don't think at this time that IP therapy should be used in current practice outside the confines of well-designed clinical trials." Dr. McGuire noted that the Gynecologic Oncology Group (GOG) is now testing IP paclitaxel(Drug information on paclitaxel) (Taxol) in a phase II study.
The results of a randomized GOG trial of high-dose chemotherapy in high-volume disease are likewise sobering. GOG investigators found no difference in progression-free or overall survival between women who had been assigned to four cycles of high-dose cyclophosphamide(Drug information on cyclophosphamide) (Cytoxan, Neosar) and platinum, and those who received eight cycles of low-dose chemotherapy.