European researchers say a test can predict whether chemotherapy will help patients with lung cancer live longer after surgery.
It seems the presence or absence of the protein ERCC1 in lung cancer cells can help doctors decide which patients can benefit from a type of chemotherapy before treatment starts.
The new study involved 28 medical centers in 14 countries, and looked at non-small-cell lung cancer, which makes up about 87 percent of all lung cancer cases.
The researchers were eager to discover if there was a more precise way to predict who would benefit from chemotherapy and focused on ERCC1 because it is involved in repairing the tumour DNA that chemotherapy aims to destroy.
For the study, University of Paris researchers Ken A. Olaussen, PhD; Jean-Charles Soria, MD, PhD; and colleagues collected 761 tumour samples and analyzed data from a very large clinical trial looking at whether post-surgery chemo improved survival for non-small-cell lung cancer patients; they found it only did so for about 4% of patients.
Less than half, (44%), carried a protein called ERCC1; the other 56% did not.
ERCC1 has been a suspect in chemotherapy resistance because it repairs DNA and platinum-based chemotherapy works by disrupting the cancer's DNA.
Volunteers with undetectable levels of the protein ERCC1, which is important in repairing DNA, had a five-year survival rate of 47 percent when treated with the platinum-based class of chemotherapy drugs such as cisplatin.
The survival rate dropped to 39 percent without treatment after surgery to remove the tumour.
When the tumours had plenty of ERCC1, the situation was reversed and those who received no chemotherapy did better than those who did.
The survival rate was 46 percent for untreated patients, compared with 40 percent for those who got cisplatin.