Loss of Heterozygosity Validated As Marker for Oral Cancer
(HealthDay News) — Specific loss of heterozygosity (LOH) is a marker for oral cancer risk, according to a study published online Nov. 5 in JAMA Oncology.
William N. William Jr., M.D., from the University of Texas MD Anderson Cancer Center in Houston, and colleagues examined whether the epidermal growth factor receptor (EGFR) inhibitor erlotinib would reduce oral cancer development in patients with high-risk oral premalignant lesions, which were defined by specific LOH profiles. A total of 395 patients with LOH profiles were enrolled, of whom 254 were classified as LOH positive. One hundred and fifty of these patients were randomized in a 1:1 ratio to placebo or erlotinib, and followed for a median of 35 months.
The researchers found that the three-year cancer-free survival (CFS) rates were 74 and 70 percent, respectively, in the placebo- and erlotinib-treated patients (hazard ratio, 1.27; 95 percent confidence interval, 0.68 to 2.38; P = 0.45). LOH-positive versus LOH-negative groups had significantly lower CFS (74 versus 87 percent; hazard ratio, 2.19; 95 percent confidence interval. 1.25 to 3.83; P = 0.01). Correlations were seen for increased EGFR gene copy number with LOH-positive status and lower CFS (P < 0.001 and P = 0.01, respectively). EGFR gene copy number did not predict erlotinib efficacy. Improved CFS was seen in association with erlotinib-induced skin rash (P = 0.01).
"These results support incorporation of LOH testing as a prognostic tool in routine clinical practice but do not support erlotinib use in this setting," the authors write.
Two authors disclosed financial ties to the pharmaceutical industry. The study was funded by OSI Pharmaceuticals, which provided the drug supply.