Benefit of Single-Agent Carboplatin in Vulnerable, Elderly Patients With Ovarian Cancer

Single-agent carboplatin conferred significantly worse survival outcomes in vulnerable, elderly patients with stage III/IV epithelial ovarian cancer compared with weekly or every 3 weeks carboplatin/paclitaxel, according to results of the EWOC-1 trial (abstract 5508), which were presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

“The 4th Ovarian Cancer Consensus Conference emphasized the need for specific trials for elderly patients. This is particularly true for the most vulnerable ones, who will receive other first-line options other than the standard 3 weekly carboplatin/paclitaxel regimen,” said presenter Claire Falandry, MD, PhD, of GINECO-Centre Hospitalier Lyon Sud, France.

The EWOC-1 trial was designed to compared three treatment options in this vulnerable patient population. The trial screened 444 patients aged 70 years or older with first-line FIGO stage III/IV epithelial ovarian cancer (median age, 80 years). Patients were screened with the Geriatric Vulnerability Score (GVS); 120 patients with a score of 3 or higher were considered vulnerable and randomly assigned to carboplatin plus paclitaxel every 3 weeks, single-agent carboplatin every 3 weeks, or weekly carboplatin plus paclitaxel.

The primary endpoint was feasibility, defined as the ability to complete 6 chemotherapy courses without disease progression, discontinuation, or death. Less than half of patients (47.5%) assigned to single-agent carboplatin were able to complete 6 cycles of therapy; 65% of patients assigned to every 3 week carboplatin/paclitaxel and 60% of patients assigned to weekly carboplatin/paclitaxel completed 6 cycles.

There was a higher rate of grade 3 or higher anemia and thrombocytopenia in the single-agent carboplatin arm, and febrile neutropenia and neutropenia were more frequent in the combination arms. Falandry said that, as expected, nausea/vomiting, constipation, diarrhea, peripheral neuropathy, and total alopecia were more frequent in the combination arms. However, severe toxicities were rare, she said.

A similar percentage of patients in each arm stopped treatment due to toxicity. There was a clear difference in the number of patients stopping treatment for lack of efficacy. About one-third of patients (30%) assigned single-agent carboplatin stopped treatment compared with less than 10% in the combination arms.

Progression-free survival was significantly worse for patients assigned to carboplatin (4.8 months) compared with every 3 weeks combination therapy (12.5 months) and weekly combination therapy (8.3 months). Overall survival for single-agent carboplatin was also significantly worse compared with every 3 week combination therapy (hazard ratio, 2.79; 95% CI, 1.57–4.96; P < .001).

Poor outcome of patients treated with carboplatin was also observed in the most vulnerable group of patients (GVS score of 4 or 5).

“Even vulnerable older ovarian cancer patients should be offered a carboplatin-/paclitaxel regimen,” Falandry concluded.

Commenting on these results, Don S. Dizon, MD, FACP, FASCO, of Lifespan Cancer Institute, said that it was important to note that over 90% of the patients in all arms of the trial either did not undergo or had suboptimal surgical cytoreduction.

Based on these results, “we should not be using single carboplatin,” he said. “That is neither kinder or more effective.”

“For vulnerable patients, the goals of treatment have to be understood,” Dizon said. “If the goal is to treat with an eye on improving survival, then carboplatin/paclitaxel is the standard of care, but it is important to remember that we should not gloss over what our patients want and should not promise cure in the absence of surgery.”