Disturbing Discovery: New Generation of Targeted Cancer Drugs Cause Tumors To Become Drug Resistant and More Aggressive

Breast-cancer-cell

“In a modest-sized lab at the Moores Cancer Center at the University of California, San Diego, scientists investigating how cancer cells develop resistance to drug treatments recently discovered something that surprised even the most seasoned members of the research team: A new generation of drugs that are currently among the most popular treatments for lung, breast and pancreatic cancers actually induce drug resistance and spur tumor growth.

“These popular cancer drugs, known as receptor tyrosine kinase inhibitors (RTKs), are actually making cancers stronger. That’s the bad news. The good news is that researchers believe they have found a way to eliminate that threat.

“Researchers found that two of the drugs — Erlotinib for lung cancer and Lapatinib for breast cancer — are effective for a while, but eventually stop killing cancer cells and begin prompting them to resist the drug and become more aggressive.

“ ‘We knew that cancer typically builds up a resistance to these and other drugs. But we did not know that these drugs actually induce tumor progression,’ said David Cheresh, Moores’ vice chair of pathology and the lead researcher on this study.”

Image: A breast cancer cell. London Research Institute EM Unit/Cancer Research UK


Drug Combo May Knock Down Lung Cancer

“Some drug-resistant cancers of the lung, pancreas and breast might be made vulnerable again by treating them with a medication already approved for another type of cancer, according to a new study led by scientists at UC San Diego.

“Researchers at UCSD Moores Cancer Center said they plan to start a clinical trial to test the use of Velcade for lung cancer in about six months. This quick start is possible because the drug is currently on the market, said Dr. Hatim Husain, an author of the study who is designing the clinical trial. For more information about the trial, call (858) 822-5182.”

Editor’s note: Clinical trials can be important treatment options for some patients. This one might be particularly appropriate for people who have taken the drug Tarceva (erlotinib) but became resistant to it. The drug combination being tested in this clinical trial has previously shown disappointing results, but the researchers are hopeful that by using molecular testing to identify patients who are more likely to benefit, they may be able to successfully use the treatment. Learn more about clinical trials here.