A study in July's New England Journal of Medicine explains that the drug Tarceva has been helpful in increasing the life expectancy of lung cancer patients. According to experts, they don't yet completely understand how the drug actually works.
Last year, researchers announced the discovery of genetic mutations that are found in about 10percent of patients, which make these individuals more likely to respond to Tarceva and a similar drug, Iressa.
In these particular patients, cancerous tumors shrunk to about half their size. Doctors have quickly developed tests to predict which patients for whom Tarceva and Iressa would work best.
Patients were reported to be more likely to respond to Tarceva if their tumors contain a certain protein or have multiple copies of a specific gene, says Frances Shepherd, a professor of medicine at Princess Margaret Hospital and a lead author of the article, according to wire reports.
The study confirmed that patients most likely to benefit from the drug include women, non-smokers, Asians and those with a type of tumor called adenocarcinoma.
Shepherd has indicated that doctors could consider Tarceva for all eligible patients without waiting for results of genetic tests. Tarceva was approved to treat people with advanced lung cancer who already have gone through chemotherapy.
Some cancer experts say the new study has a number of profound weaknesses. Because taking slices of lung tumors is extremely invasive, the study's authors were able to examine tissue from fewer than half of the patients. They analyzed mutations in only about 25percent, Shepherd says.
The study's findings could benefit the companies that make and distribute Tarceva by helping them maintain a large market for their drug. Tarceva is distributed by Genentech and made by OSI Pharmaceuticals, which also helped fund the study.
-- Compiled from wire reports
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