|
medpundit |
||
 |
 |
|
Saturday, December 11, 2004By screening tumor samples for 21 genes implicated in the disease, the test provides doctors with a much more detailed picture of the nature of breast cancer in each patient. It is a step toward the goal of "individualized cancer care.'' Results described in several studies at the conference show that the test does a good job at identifying women who are least likely to have a recurrence. These women might want to forgo chemotherapy, which has multiple side effects and can cost more than $15,000. On the other hand, women found by the test to be at high risk of recurrence may still benefit from that knowledge, because their cancers appear to be much more responsive to chemotherapy than those in the low-risk group. A study presented at the conference showed that patients identified as high-risk by the new test were 70 percent less likely to have a recurrence if they had chemotherapy. The study involved choosing the 21 genes for testing from other studies that showed they correlated positively with aggressive breast cancer expression. The authors then looked for those genes in breast tumors that had been removed as part of another study that looked at the effectiveness of tamoxifen in preventing breast cancer. They developed a scoring system of low, medium, or high risk for recurrence based on the number of genes expressed by the tumors. There genetic assay appears to be quite predictive, more so, in fact, than the usual methods of predicting aggressiveness, such as patient age, tumor size, or how chaotic and immature the tumor cells are: Many patients (51 percent of the patients in the study) were categorized as having a low risk, and their rate of distant recurrence at 10 years was 6.8 percent. A smaller group of patients (27 percent) was categorized as having a high risk; their rate of distant recurrence at 10 years was 30.5 percent — a risk similar to that observed among patients with node positive disease. It's not a perfect predictor, however, since some of the low scoring tumors still managed to recur: A low risk was defined as a recurrence score of less than 18, an intermediate risk as a score of 18 or higher but less than 31, and a high risk as a score of 31 or higher. There were 28 recurrences in the low-risk group, 25 in the intermediate- risk group, and 56 in the high-risk group. But still, it's a very promising first step toward individually tailored therapeutics. posted by Sydney on 12/11/2004 07:48:00 AM 0 comments 0 Comments: |
|
