PACLITAXEL CARBOPLATIN FOR UTERINE CARCINOSARCOMA

NEW YORK (Reuters Health) May 17 - An outpatient regimen of paclitaxel and carboplatin has activity against carcinosarcoma of the uterus, researchers report in the April 26th online issue of the Journal of Clinical Oncology.

The response rate was roughly 50%, and the toxicity was manageable, they say. The median progression-free survival was 7.6 months, and the median overall survival was 14.7 months.

Uterine carcinosarcoma is typically aggressive. Patients usually have metastases by the time they're diagnosed, and the overall survival rate is poor, lead author Dr. Matthew A. Powell of Washington University School of Medicine, St. Louis, told Reuters Health by e-mail.

Paclitaxel-carboplatin "seems at least as good as the ifosfamide-plus-paclitaxel combination, with likely less toxicity," Dr. Powell said.

A phase III trial now underway is comparing it to the current standard therapy, ifosfamide with paclitaxel. Dr. Powell and his colleagues note in their paper that ifosfamide with paclitaxel is less than ideal because of its "toxicity, multiday schedule, and limited activity."

The report notes that along with less toxicity, another factor in favor of the paclitaxel-carboplatin regimen is that it's currently approved for use against nine different tumor types. This means that its toxicity profile is predictable, which lets researchers streamline their tests of this regimen in combination with new agents.

A 2008 study found that paclitaxel-carboplatin was less expensive than ifosfamide regimens, in part because of in-patient costs associated with the latter.

The current study evaluated 46 patients with stage III or IV recurrent or resistant carcinosarcoma, none of whom had previously received cytotoxic chemotherapy for this cancer.

Each was initially given paclitaxel 175 mg/m2 as a 3-hour intravenous infusion, followed by carboplatin dosed to an area under the serum concentration-time curve = 6.0 over 30 minutes, on day 1 of a 21-day cycle. More than half of the participants completed at least six such cycles.

Six patients (13%) had a complete response, 19 (41%) had a partial response and 11 (24%) achieved stable disease.

Toxicity was mostly hematologic, primarily neutropenia, followed by anemia and thrombocytopenia. Nonhematologic toxicities were primarily fatigue and sensory neuropathy.

There were no deaths attributed to therapy.

J Clin Oncol 2010.