• 9/1/2005
  • New York, NY
  • staff
  • www.cancerpage.com

The plasma level of osteopontin, a marker for tissue hypoxia, can predict whether the radiosensitizing agent nimorazole will be useful in patients with head and neck cancer, new research indicates.

Adequate tissue oxygen levels are needed for radiotherapy to be most effective. Nimorazole works by modifying hypoxic environments, making the tissues more sensitive to radiotherapy.

“Our study suggests that high plasma concentrations of osteopontin predict the need for hypoxia modification” with an agent like nimorazole, lead author Dr. Jens Overgaard and colleagues, from Aarhus University Hospital in Denmark, note. Still, further studies are needed to determine the exact plasma levels that are important.

The present findings, which appear in the August 30th online issue of The Lancet Oncology, are based on a study of 320 patients enrolled in the Danish Head and Neck Cancer Study Group (DAHANCA) 5 trial, which compared the effects of radiotherapy combined with nimorazole or placebo. Stored samples from the subjects were analyzed to determine osteopontin levels, which were then correlated with outcomes.

Patients treated with nimorazole had about half the risk of locoregional tumor failure and disease-specific mortality compared with control subjects.

On further analysis, the benefits of nimorazole therapy on locoregional tumor failure and disease-specific mortality were confined to subjects with high osteopontin levels. By contrast, among patients with low or intermediate osteopontin levels, treatment with nimorazole seemed to offer no benefit over placebo.

“We have shown that high plasma concentrations of osteopontin in patients with squamous-cell carcinoma of the head and neck are associated with poor outcome after radiotherapy only, but that the prognosis of these patients can be improved by the use of the hypoxia radiosensitizer nimorazole with radiotherapy,” the investigators conclude.

Source:
Lancet Oncol 2005