Tumor Debris That’s Left After Treatment Can Reignite Cancer, Study Reports

Tumor Debris That’s Left After Treatment Can Reignite Cancer, Study Reports

Most cancer treatments create the perfect environment for the diseases to rejuvenate,  researchers discovered in a study that could explain how tumors become resistant to chemotherapy.

The tumor debris left when cancer cells are killed can trigger potent inflammatory reactions, the researchers learned.

If any cancer cells are lingering in that environment, they can get a growth pop and stop responding to chemotherapy, according to the team’s Journal of Experimental Medicine article. Their findings apply to a number of cancers, including prostate cancer.

But the study, led by researchers from Harvard’s Beth Israel Deaconess Medical Center, offers good news, too. The team discovered that natural anti-inflammatory molecules called resolvins increase the clearance of cancer cell debris, if administered with the treatment. That’s why they titled their study “Resolvins suppress tumor growth and enhance cancer therapy.”

Luckily, resolvins are already being tested in clinical trials as anti-inflammatory treatments, which could make their road to cancer patients relatively short.

Researchers explored cancer processes in mice to come to their conclusion that resolvins can boost cancer debris clearance.

The animals were treated with chemotherapy or targeted therapies. After the treatments, they collected cell debris — pieces of dead cancer cells — and combined them with a tiny amount of tumor cells.

Normally, the amount they used is too small to generate cancer. But their experiments showed that when combined with tumor debris, the cells’ growth soared. In fact, growth rates were 100 times that of cancer cells grown without the debris.

“Our findings reveal that conventional cancer therapy is essentially a double-edged sword,” Dr. Mark Kieran, the study’s co-senior author, said in a press release.

“But more importantly, we also found a pathway to block the tumor-stimulating effects of cancer cell debris — using a class of mediators called resolvins,” added Kieran, who directs the Pediatric Brain Tumor Program at Dana-Farber Cancer Institute/Boston Children’s Hospital and is an associate professor of pediatrics at Harvard Medical School.

Resolvins exist naturally in our bodies, where they act to contain inflammation and promote tissue health. They are derived from fatty acids, including omega-3 and omega-6.

The team thought the molecules might be able to harness the inflammation and improve the clearance of the tumor cell debris. Additional experiments proved them right. Giving resolvins at the same time as the cancer therapy significantly improved the clearance.

Researchers said the findings indicate that resolvins may be a valuable add-on treatment to other types of cancer therapies, improving treatment outcomes.

“Resolvins are already in advanced clinical trials for a number of inflammatory diseases and can be rapidly translated to the oncology population,” said Kieran, suggesting that the route to testing the compounds in cancer patients is relatively short.