A new study has shown that some well-known drugs in new dosages can limit the spread of cancer metastases. The results are published in the journal ACS Chemical Biology.

Drugs used to treat depression, heart disease, and parasitic diseases can reverse key changes in cancer cells related to their ability to spread—metastasize. It is difficult to treat and is the main cause of death from cancer.

When examined under a microscope, cancer cells look abnormal. For more than 150 years, scientists have been using changes in the size of cell nuclei to diagnose cancer and its severity. Often, they are associated with an increased spread of abnormal cells, reducing the patient’s chances of survival. However, few treatments specifically target metastasis.

To solve this problem, researchers from the Universities of Edinburgh, Montreal and Eastern Finland tested drugs in the lab that reversed changes in nuclear size in three types of cancer – prostate, colon and lung.

During screening, biologists have identified many drugs that have not previously been used to treat cancer, but could help. Among the drugs are those used to treat depression, heart disease, and kill parasitic worms. There are more than 13 drugs in total.

Because drugs can target certain types of cancer cells and are generally nontoxic, they can be added to existing treatments to reduce metastasis without further amplifying the side effects of chemotherapy that already exist.

The researchers also found that for each type of cancer, a different set of drugs at different dosages can change the size of the nucleus in the opposite direction, since the changes are associated with an increase in metastasis. This reduced the ability of the cell to move around the body and invade tissues. Scientists will continue to study drugs that may help in the treatment of cancer.