by Kristin Jenkins
Contributing Writer, MedPage Today
The first randomized phase III clinical trial to compare irinotecan (Camptosar, Camptothecin-11, CPT-11) and cisplatin (Platinol, Platinol-AQ, CDDP) with standard of care -- paclitaxel (Taxol, Onxal) plus carboplatin (Paraplatin) -- in patients with clear cell carcinoma (CCC) of the ovary found no significant survival benefit between the groups.
With a median follow-up of 44.3 months, 2-year progression-free survival rates were 73.0% in the irinotecan-plus-cisplatin (CPT-P) group and 77.6% in the paclitaxel-plus-carboplatin (TC) group (HR 1.17; 95% CI 0.87 to 1.58). Two-year overall survival rates were 85.5% with CPT-P and 87.4% with TC (HR 1.13; 95% CI 0.80 to 1.61).
Both regimens were well tolerated, although the toxicity profiles differed significantly, Aikou Okamoto, MD, of Jikei University School of Medicine in Tokyo and colleagues in the Japanese Gynecologic Oncology Group reported online in theJournal of Clinical Oncology.
"The previous randomized phase II study[JGOG3014] showed a tendency of progression-free survival superiority of the CPT-P arm in a subset analysis of patients without residual disease or with residual disease of less than 2 cm," the researchers wrote. "However, we could not identify the survival advantage of CPT-P in any subgroup analyses by region, stage, and size of the residual disease in the current phase III randomized trial."
The study also revealed the limitations of existing anticancer agents to improve prognosis in patients with ovarian CCC. Identification of driver mutations "is a crucial first step toward personalizing treatment of CCC," Okamoto and colleagues emphasized.
Studies of metastatic clear cell renal cancer have demonstrated the effectiveness of using a combination of targeted treatments such as a PI3K-Akt-mTOR pathway inhibitor as well as anti-angiogenic agents and new immunotherapy drugs, the researchers said. "Therefore, we emphasize that therapeutic regimens should consider such combinations and/or target drugs to improve the prognosis of CCC of the ovary."
The negative results of this trial highlight two major challenges in cancer research,Emese Zsiros, MD, PhD, of Roswell Park Cancer Institute in Buffalo, NY, said in an interview.
"In vitro studies on cancer cell lines often do not translate to clinical benefit in patients given the heterogeneity and complexity of cancer in real life," she explained. "Also, if a phase II study does not show significant activity of a new drug or drug combination, it is unlikely to detect a significant clinical benefit in a large phase III study."
Zsiros, who was not affiliated with the study, also noted that while CCC accounts for only 4-12% of all ovarian cancers in the U.S. and Europe, it is much more common in Japan, accounting for more than 20% of all ovarian cancers.
Unlike serous ovarian cancer, CCC is often associated with a large one-sided pelvic mass and an increased incidence of hypercalcemia and vascular thromboembolic complications such as deep venous thrombosis and/or pulmonary embolism, she pointed out. The lower proliferation rate and increased resistance to traditional chemotherapeutic agents make CCC "a much more difficult disease to treat."
Given the relatively poor prognosis and similarity to clear cell renal cancer, patients with CCC of the ovary are best treated as part of a clinical trial exploring alternative or novel agents, Zsiros suggested.
In the international, multi-institutional study, 667 patients were recruited at 129 centers in Japan, Korea, France, and the U.K., from September 2006 to February 2011. Japanese women made up 93.5% of the study population.
The median age in both the experimental and standard-of-care groups was 53. A total of 411 patients (66.4%) had stage I disease, and 33.6% had stage II to IV disease. Of the latter group, 23% had stage III/IV disease.
Patients were randomly assigned to receive either:
- irinotecan at 60 mg/m2 on days 1, 8, and 15 plus cisplatin at 60 mg/m2on day 1 every 4 weeks for six cycles (CPT-P group); or
- paclitaxel at 175 mg/m2 plus carboplatin at an area under the curve of 6.0 mg/mL/min on day 1 every 3 weeks for six cycles (TC group).
Of the 619 patients eligible for evaluation, the 332 in the CPT-P group experienced more grade 3/4 anorexia, diarrhea, nausea, vomiting, and febrile neutropenia. The 335 patients in the TC group had grade 3/4 leukopenia, neutropenia, thrombocytopenia, peripheral sensory neuropathy, and joint pain more frequently, the study showed.
No deaths related to treatment were reported, the researchers said.
Okamoto disclosed no conflicts of interest, but several of the other study authors disclosed relationships with industry.
- Reviewed by F. Perry Wilson, MD, MSCEAssistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner
LAST UPDATED 07.15.2016
Journal of Clinical Oncology
Source Reference: Okamoto A, et al "Randomized phase III trial of irinotecan plus cisplatin compared with paclitaxel plus carboplatin as first-line chemotherapy for ovarian clear cell carcinoma: JGOG3017/GCIG trial"JCO 2016; DOI: 10.1200/JCO.2016.66.9010.
