Few treatment options exist for patients with head and neck cancers who develop a second tumor or whose disease recurs in an area that has previously received radiation. Data from an international study reveal a possible new combination treatment regimen that offers a significant survival advantage for many of these patients.
The details of the study were presented today at the 47th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Denver, Colo.
"Not only did this clinical trial show efficacy with our regimen, but it appears to significantly increase the probability of survival when compared to the current standard treatment," said Eric Horwitz, M.D., co-principal investigator of the Radiation Therapy Oncology Group study (RTOG 99-11) and clinical director in the radiation oncology department at Fox Chase Cancer Center.
The study was conducted with patients from the U.S. and Canada. Participants had recurrent squamous-cell head and neck cancer or a second primary tumor that developed in the area where they had previously been irradiated. Investigators enrolled 105 patients between March 2000 and June 2003 and 99 patients were eligible for analysis. Of those, 23 percent had second primary tumors in the site previously treated with radiation while the remainder had cancers that recurred. The predominant primary sites were the oropharynx (40 percent) and oral cavity (27 percent). The oropharynx is the middle portion of the tube connecting the oral and nasal cavities to the voice box and esophagus.
Patients were treated with split course hyperfractionated radiation therapy (twice a day for five days every two weeks for four cycles). They also received chemotherapy with cisplatin (daily every two weeks for four cycles) and paclitaxel (daily every two weeks for four cycles).
The median follow-up for surviving patients was 23.6 months. Median survival was 12.1 months.
For patients treated with the current standard of treatment of chemotherapy alone, median survival is 6 to 8 months. One-year survival rates are typically less than 35 percent. For those who received a combination treatment through an earlier RTOG trial (split-course re-irradiation combined with hydroxyurea and 5-FU chemotherapy), the estimated one- and two-year overall survival rates are 41.7 percent and 16.9 percent respectively. In the study presented today, 50 percent of patients survived for at least a year while nearly 26 percent of patients survived two years.
"The side effects from this experimental regimen were significant, but these patients were among those with the most serious cancers," explained Horwitz.
Eight of the patients in the study had grade 5 toxicities, or fatal side effects. Thirty-four percent of the patients had grade 4 acute and late toxicities. Other acute toxicities included leukopenia, anemia and diarrhea.
The impetuses for this international study were phase I and phase II studies conducted at Fox Chase Cancer Center, where this treatment regimen combining radiation therapy with concurrent chemotherapy was piloted.
Horwitz says researchers will test this treatment approach in an RTOG phase III randomized clinical trial comparing this regimen to chemotherapy only.