I have a hunch that Big Pharma probably didn't want this news to be published.

Buck study: chemotherapy may promote development of cancer later in life
Knight Ridder/Tribune Business News

12-02-08

Dec. 1--The same chemotherapy that cures a patient's prostate cancer may increase that patient's chances of developing cancer later in life in tissue adjacent to the original cancer, new research by the Buck Institute for Age Research indicates.

Cells shut down and stop dividing when their DNA is damaged, as occurs during chemotherapy. But the Novato institute's new study found that when the cells shut down they spew proteins into their surrounding environment. The process, called cellular senescence, causes inflammation and sets up conditions that support the development of age-related diseases including, ironically, cancer.

The study has major implications for age research because it suggests that a cellular response that likely evolved to protect from cancer early in life can promote disease later in life, said Buck faculty member Judith Campisi, lead author of the study, which appears in Tuesday's online version of PLoS Biology.

Campisi said her research jibes with an evolutionary theory of aging first formulated in the 1950s that explains the trade-offs between early fitness and late-life survival.

"For most of our evolutionary history, we (humans) died of external hazards: lions eating us, infection, starvation," Campisi said. "There were no old people in our evolutionary history because they were all dead due to these external hazards. Now that we're living in a much safer environment, any process that had effects that were bad but took a long time to manifest

themselves, we're living with the consequences of them."

Campisi said the study, which compared tissue samples from prostate cancer patients before and after chemotherapy, provides a cautionary note for younger patients who receive treatments that could promote the development of further cancers later in life. She said the findings help explain why cancer patients feel so sick when they get chemotherapy.

"Chemotherapy is brutal -- both normal and cancerous cells are forced into senescence, with resulting secretion of inflammatory factors that can produce flu-like symptoms during treatment," Campisi said.

She said the study points out the need for new biologically targeted therapies for cancer that exploit more specific differences between normal and cancer cells. Current DNA-damaging chemotherapy focuses on cells that divide rapidly -- affecting cancer cells as well as all dividing cells including cells in the alimentary canal and hair follicles.

The challenge now, Campisi said, is to find a way to preserve the anti-cancer activity while dampening its pro-aging effects. Ongoing research at the Buck Institute involves efforts to encourage the body to eliminate senescent cells more rapidly than it normally does.

"That's got to be the goal," Campisi said. "Although senescent cells exist for the good purpose of preventing cancer, we don't want them to hang around -- we want the body to be able to get rid of them."