For the 215,000 people in the U.S. diagnosed with lung cancer every year, the need for better diagnostic tools is particularly urgent, says Toner's collaborator Thomas Lynch, chief of the center for thoracic cancers at Mass General. In lung cancer patients, even a small biopsy bears risk of blood loss, infection and, in rare instances, collapse of the affected lung.
Herbst cautions that the findings need to be validated in larger clinical trials and at other medical centers. At Mass General, the researchers are now evaluating how well the chip measures cancer growth and responses to treatment in patients with breast, ovarian and prostate cancers.
By direct examination of cancer cells in blood, the CTC-chip might also uncover new targets for therapy and help determine when and how metastases arise. Toner sees unlimited possibilities once the chip has proved itself in bigger clinical studies. In the future, he remarks, it could become a screening tool to find nascent cancers and even "could be used at annual checkups."
Getting Personal with Cancer Care
Cancer therapies often fail because of genetic differences among individuals. In personalized cancer care, physicians would tailor treatment to the particular features of each patient's cancer. For example, colon cancer patients often receive treatments with antibodies directed at a growth factor receptor. Although this therapy, costing nearly $10,000 per month, can prolong life and make some patients feel better, it works only in those who have the normal version of K-ras, a gene for a signaling protein crucial for tumor growth. So if physicians examine the tumors for K-ras mutations before prescribing these drugs, they can direct care to those it would help, sparing others the costs, hassle and possible side effects of treatment. E.S.
Note (3/30/09): The headline was modified after publication to correct an error.
This article was originally published with the title A Chip against Cancer.