A sugar supplement might be able to slow the growth of mesothelioma and others types of cancer.
The sugar supplement is called mannose. Mannose occurs naturally in some fruits, including cranberries. It is also sold as a nutritional supplement.
Researchers with Cancer Research UK and Worldwide Cancer Research say mannose slowed the growth of tumors in mice. The test mice had leukemia, bone cancer, ovarian cancer, or bowel cancer.
In a new report in the journal Nature, the researchers say mannose made mouse tumors smaller. It also helped chemotherapy work better and helped some mice live longer.
How Does Mannose Slow Tumor Growth?
All cells in the body need glucose to grow. This includes cancer cells.
Cancers like mesothelioma need even more glucose than healthy cells. The mannose sugar supplement interferes with glucose and limits how much sugar cancer cells can use.
“Tumours need a lot of glucose to grow, so limiting the amount they can use should slow cancer progression,” says lead author Kevin Ryan, Professor at the Cancer Research UK Beatson Institute.
Slowing Cancer Growth in Mice
To test how mannose might slow cancer growth, scientists put the sugar supplement in the drinking water of sick mice. These mice had pancreatic, lung or skin cancer.
Doctors found that tumors in mice that drank the supplement grew much more slowly. Just as importantly, the mice did not have any obvious side effects.
In another test, the mice were given two popular chemotherapy drugs – cisplatin and doxorubicin. Some cancer cells responded well to the treatment while others did not.
Cells with low levels of a particular enzyme were more sensitive to mannose. Doctors say they could use this enzyme to predict which cancer patients might respond to the treatment.
The Sugar Supplement and Mesothelioma Patients
Although this is early research, Dr. Ryan says he hopes that cancer patients could one day take mannose to help chemotherapy work better. One of the best things about mannose is that it does not make patients even sicker.
This is especially important for people with pleural mesothelioma or peritoneal mesothelioma.
Mesothelioma tumors grow quickly and patients do not have many options to slow them down. This is because mesothelioma cells often do not respond to standard cancer drugs.
If scientists can prove that mannose works in people as well as it works in mice, it could be good news for mesothelioma patients.
“Mannose could be a simple, safe, and selective therapy in the treatment of cancer,” says Dr. Ryan.
More testing of the mannose sugar supplement is needed before doctors will know how well it works for people with mesothelioma. In the meantime, mesothelioma patients should not take any supplements or change their diet without talking to their doctor first.
Gonzalez, P, et al, “Mannose impairs tumour growth and enhances chemotherapy”, November 21, 2018, Nature, https://www.nature.com/articles/s41586-018-0729-3