A Targeted Attack
August 1, 2018
A lung cancer diagnosis can be devastating. The disease has just an 18.6 percent five-year survival rate, and it’s the leading cause of cancer deaths in the United States. But new research may offer hope.
A combination of two currently available drugs could treat most cases of lung cancer, UT Southwestern researchers say. The Food and Drug Administration-approved drugs — one that’s already used to treat some cancers and another that typically fights inflammatory diseases like arthritis — have been effective in treating brain cancer in the lab.
Zeroing In on Cancer
The drug combo treatment is a type of targeted therapy. With targeted therapy, experts identify abnormalities that are specific to cancer cells and develop drugs that can attack those cells without harming other, healthy cells.
Targeted therapies are already approved as treatments for many types of cancer, including a small percentage of lung cancers. Now, there’s the possibility that this type of treatment might work for the majority of lung cancers.
Researchers know that the epidermal growth factor receptor (EGFR) is expressed in many types of cancer, but a drug that targets EGFR works well only for a small subset of lung cancer cases. When scientists tried to figure out why they found that, in the cases where it did work for lung cancer, those tumors had a genetic mutation.
A Breakthrough at UT Southwestern
The UT Southwestern research team discovered that when targeted therapies block EGFR, most of the time — when there’s no genetic mutation — the cancer releases a protein called tumor necrosis factor (TNF). “By increasing TNF, the cancer cells fight back, to go to their original state,” explains Amyn Habib, M.D., Associate Professor of Neurology and Neurotherapeutics and a member of the Simmons Cancer Center at UT Southwestern.
Adding a second drug that blocks TNF makes the combo treatment effective against lung cancer, lab studies have found. Once TNF is blocked, the cancer responds to the EGFR treatment.
“The idea that you could block both [EGFR and TNF] in patients is very feasible,” Dr. Habib says. The two drugs are already FDA-approved, so researchers aim to launch a phase two clinical trial within a year.
Better Survival Rates, Fewer Side Effects
For many people diagnosed with lung cancer, treatment follows a familiar path — surgery to remove the tumor, then radiation and/or chemotherapy to destroy remaining cancer cells. While these treatments may be effective, radiation and chemotherapy don’t only target cancer cells — they can harm healthy tissue, too. Chemotherapy’s side effects can include hair loss, mouth sores, digestive issues, increased infection risk, and fatigue.
If the new combo therapy works, it could be used along with surgery to treat most people with lung cancer. Both drugs are well tolerated and have relatively few side effects. And the new therapy may improve lung cancer survival rates, says Dr. Habib.
The two-drug combo treatment could also work for a type of brain cancer called glioblastoma, which spreads aggressively through the brain. The clinical trial is expected to include both lung cancer and brain cancer patients. If the treatment is effective, it may work for other types of cancer as well, including colon and head and neck cancers.
Lung Cancer by the Numbers
1Ranking of lung cancer among causes of cancer deaths in both men and women.
26%Proportion of all cancer deaths attributed to lung cancer in 2017.
85%Proportion of lung cancers where the two-drug combo treatment is expected to be effective.
3.9%Proportion of people eligible for low-dose CT screening for lung cancer who were tested in 2015. That’s just 262,700 of the 6.8 million people who could benefit from the test.
1 in 3Adults with mental illness who smoke. That’s more than double the 15% of adult smokers with no mental illness.
234,030Estimated number of new cases of lung cancer diagnosed in the U.S. in 2018.
1992Year when the lung cancer diagnosis rate peaked in the U.S. It has been declining steadily since then.
9Years of life a smoker can regain, on average, by quitting at age 40 or earlier instead of continuing to smoke for a lifetime.
Sources: American Cancer Society, National Cancer Institute, The Tobacco Atlas, UT Southwestern