A study found that the method -- first used in the 1970s -- was almost three times as likely to detect hidden lymph-node tumors.
Using conventional tests, researchers discovered hidden tumors in 7 percent of 736 former breast cancer patients whose lymph nodes had been classified as "disease free." Using the newer method, called "immunohistochemical testing," hidden tumors were found in 20 percent of the same 736 patients.
The research is published in this week's issue of Lancet, a British medical journal. Its authors include experts from the University of Southern California, the European Institute of Oncology in Milan and the Ludwig Institute for Cancer Research in London.
Dr. Alexander Neville, of the Ludwig Institute said the tests can help doctors predict whether cancer is likely to recur, and allow them to identify patients who could benefit from early chemotherapy treatment.
"Immunohistochemical testing started in the 1970s but it's taken a long time for it to be adopted," he said. "This is so simple anyone can do it."
Under the method, researchers add a color stain to the lymph node tissue being examined. The stain highlights the cancer cells, which allows doctors to isolate them more quickly, Neville said.
He said similar tests are available for colon cancer, lung cancer, melanoma and prostate cancer.
Research laboratories commonly use the immunohistochemical tests for patients considered at risk of recurring cancer, but rarely for patients who have been declared disease-free, said Dr. Tim Perrenn, breast cancer specialist with the Cancer Medicine Research Unit in Leeds, England.
Gordon McVie, director general of the London charity Cancer Research Campaign, said he hoped the study would push doctors to increase the use of new testing methods.
If women who died of breast cancer "had the benefit of the new technology, their lymph nodes would have been reported by the pathologist as having cancer cells in them, and they would then have gotten chemotherapy and they would have been alive," McVie said.
Perrenn classified the study results as "potentially quite exciting." But, he said, he was cautious because the research was only part of a larger study on chemotherapy.
He said he would like to see a wider, specific investigation into the findings to verify the results.
Written By Caroline Byrne