NEW YORK (Reuters Health) – For cases of locally extensive advanced skin squamous carcinoma, novel combination therapy with 13-cis-retinoic acid (13cRA), interferon-alfa (IFN-alfa) plus cisplatin is clinically active, researchers report.
In a phase II trial, Dr. Scott M. Lippman, from The University of Texas M. D. Anderson Cancer Center, Houston, and colleagues treated 39 patients with advanced squamous cell skin cancer. Treatment included IFN-alpha, 5 million IU/m² three times a week, 13cRA 1 mg/kg daily, and cisplatin 20 mg/m² once a week.
The research team also analyzed the ability of this therapy regimen to inhibit growth, cell cycle, and apoptosis activity in two squamous skin cancer cell lines, namely SRB1-m7 and SRB 12-p9), according to their report in the Journal of Clinical Oncology for January 15.
During a median of 9 months of therapy, the overall response rate of the combination therapy was seen in 12 of 35 patients, and the complete response rate during a median of 35.4 months of treatment was seen in 6 of 35 patients. In locally advanced cancers, a response rate was seen in 8 of 12 patients, response occurred in only 4 of 23 patients with metastatic disease (p = 0.007), the investigators report.
Median patient survival was 14.6 months, and the researchers estimated the 1-year survival rate at 58%, the 2-year survival rate at 32% and the 5-year survival rate at 21%.
Adverse affects of the treatment regimen included mild to moderate fatigue and mucocutaneous dryness. Moderate to severe neutropenia occurred in 38% of the patients and 6% of the patients experienced neutropenic fever. There were no deaths related to treatment, Dr. Lippman's team notes.
"Our present results suggest that it is now time to conduct a phase III trial to confirm the activity of IFN-alfa, 13cRA, and cisplatin in locally advanced skin squamous cell carcinoma," the researchers conclude. They suggest a comparison of "this regimen with more standard cytotoxic chemotherapy or combined IFN-alpha and 13cRA, both of which also have been shown to be active primarily in locally advanced disease."