National Taiwan University Medical Center researchers have developed a simple five-gene test that can determine what type of cancer sufferer most requires chemotherapy. The method is similar to existing tests used for breast and lymphatic cancer patients.

This new genetic test is still in the experimental stages, and requires further testing on patients, so it will not be available for broad use for a few years. However, the method could be widely used in the future, eliminating the need for highly-trained professionals at a handful of centers to undertake genetic testing of this type, and for this, it has won international approbation.

Vanderbilt University Cancer Center oncologist and former chair of the American Clinical Tumor Association, Dr. Johnson, says that the test is further demonstration that understanding a persons genetic makeup is helpful to determining how to treat his or her cancer. The test even allow us to avoid doing chemotherapy on some patients, accurately indicating which patients will have no reaction to existing drugs, and showing when the use of an experimental treatment would be best.

National Taiwan University Institute of Contagious Diseases doctoral student Chen Xuanyu first took up the project, which was jointly guided by National Taiwan University Hospital vice-president Yang Panchi, Chunghsing Medical Institute associate professor Chen Jianwei and National Taiwan University Institute of Contagious Diseases professor Chen Weijian. The results of the trial were published this past Thursday in the New England Journal of Medicine.

Lung cancer is the leading worldwide killer among cancers, and the majority of lung cancer tumors have already spread to other parts of the body when the diagnosis is made. Among patients diagnosed when the cancer is in its early stages, about 20 percent undergo surgery to remove the diseased portion of lung and then have chemotherapy. This treatment can improve survival rates, but some early-stage patients experience low recurrence rates, and undergoing chemotherapy does not improve their situation markedly. Some other patients have recurrences of cancer, or even experience cancers more lethal than the one with which they were originally diagnosed. Currently there is no good way of distinguishing between these two types of patients in order to judge who would benefit from chemotherapy.

This project at NTU looks at high- and low-risk patients and provides a better means of distinguishing between the two. Researchers analyzed tumor biopsies from 125 patients at various stages of lung cancer. Results showed that for 16 genetic types, chemotherapy did not seem to affect recurrence rates positively or negative, or impact mortality. Further analysis showed that only five genes fit the high-risk category.

Researchers did related genetic testing on half the tissue samples obtained, discovering that a strong correlation between one gene and chemotherapy. Based on the strength of activity of the five genes, median survival rate for the low-risk group was 40 months, while that of the high-risk group was just 20 months. Median recurrence period for the low-risk group was also stretched out to 29 months from the 13 months figure experienced by the high-risk group.