Levels of all three markers were significantly higher in the men who died of prostate cancer in the subsequent 11 to 16 years, the study found.
Concato said the study is just a first step toward use of the biomarkers to guide prostate cancer treatment. "Other groups should replicate our results," he said. "Based on these results, there should be an effort at developing therapies that attack the mechanisms reflected by these markers."
Concato said he has proposed a clinical trial that "would treat patients based on marker status, as positive or negative."
The editorial by Dr. Edward P. Gelmann, chief of the division of hematology/oncology and deputy director of the Herbert Irving Comprehensive Cancer Center at Columbia University, challenged the value of all three biomarkers.
A number of previous studies have shown that results of p53 tests "are not reproducible from one laboratory to the next," Gelmann said. "There is great variability in both technique and results." Though p53 has been studied as a biomarker for a number of cancers, he said, it is used only for one rare malignancy, transitional cell carcinoma of the blood.
As for bcl-2, Gelmann said that the number of cases in the study with a positive reading was too small to provide proof of its predictive power. "To prove it has prognostic significance would require would require a larger trial," he said.
And the measure of blood vessel density done in the study was not necessarily reproducible, Gelmann said. "It was done by an individual observer without anyone else checking it," he said.
In response, Concato said that "the editorial doesn't mention several major strengths of the study, and it misrepresents what was known before we did our study."
"For example, showing a link betwee
All rights reserved