Digestive Health Key to Cancer Survival: Help for Patients Undergoing Chemotherapy

Treating cancer can be a long process with many pitfalls. Now, though, scientists have found something that could help patients undergoing treatment. They've discovered that if a patient's gastrointestinal tract remains healthy and functioning, their chances of survival increase exponentially. Now, they've revealed a biological mechanism that preserves the gastrointestinal tracts in mice who were delivered lethal doses of chemotherapy.

Treating a cancerous tumor can be difficult. Patients often have to undergo chemotherapy in order to kill the cancer, yet too much of this radiation can also affect the patient. That's why Jian-Guo Geng and his team decided to investigate whether it was possible to keep a patient alive while still delivering what would usually be considered lethal doses of radiation.

"All tumors from different tissues and organs can be killed by high doses of chemotherapy and radiation, but the current challenge for treating the later-staged metastasized cancer is that you actually kill the patient before you kill the tumor," said Geng in a news release.

Using mice, the researchers discovered that when certain proteins bind with a specific molecule on intestinal stem cells, it revs intestinal stem cells into overdrive for intestinal regeneration and repair. Geng's lab has worked with these molecules, called R-spondin1 and Slit2, for more than a decade. They can repair tissue in combination with intestinal stem cells residing in the adult intestine. Stem cells naturally heal damaged organs and tissues, but so-called "normal" amounts of stem cells in the intestine simply cannot keep up with the wreckage left behind by lethal doses of chemotherapy and radiation.

Yet there's a way to get around this issue. The large amount of extra stem cells protected the intestine and gastrointestinal tract. This means that the patient could ingest nutrients and the body could perform other critical functions, preventing bacterial toxins in the intestine from entering the blood circulation.

In the end, about 50 to 75 percent of the mice treated with the molecule survived what would have been lethal doses of chemotherapy. The mice that didn't receive the treatment ended up dying from the chemotherapy.

"Now you have a way to make a patient tolerant to lethal doses of chemotherapy and radiotherapy," said Geng. "In this way, the later-staged metastasized cancer can be eradicated by increased doses of chemotherapy and radiation."

Needless to say, there's a long way to go before this treatment can be tested in humans. Yet it does provide an important step forward when it comes to the use of chemotherapy in tumor treatments.

"If you can keep the gut going, you can keep the patient going longer," said Geng. "Now we have found a way to protect the intestine. The next step is to aim for a 100 percent survival rate in mice who are injected with the molecules and receive lethal doses of chemotherapy and radiation."

The findings are published in the journal Nature.