Scientists from the Cancer Research U.K. Cambridge Institute have discovered in a landmark study that there are five distinct types of prostate cancer.

The study shows how to distinguish between the five types of prostate cancer, which could help doctors decide on the best treatment for each specific case. The results of the study could also help doctors identify which tumors would spread more aggressively and which ones would spread more slowly.

Prostate cancer is the most common form of cancer occurring among men in the U.K., with 41,700 new cases diagnosed and 10,800 deaths each year.

Prof. Malcolm Mason, a cancer expert from the Cancer Research U.K. Cambridge Institute, said prostate cancer may behave one way in a patient and another way in another patient, making it a challenge to treat.

"It can either behave like a pussycat - growing slowly and unlikely to cause problems in a man's lifetime - or a tiger - spreading aggressively and requiring urgent treatment," Mason said, according to the Cancer Research U.K. Cambridge Institute. "This means that some men may get treatment they don't need, causing unnecessary side effects, while others might benefit from more intensive treatment."

Mason said the new study could be helpful in giving doctors "better information to guide each man's treatment" and allowing them to decide which treatment is best for those with more aggressive types of prostate cancer.

"Ultimately this could mean more effective treatment for the men who need it, helping to save more lives and improve the quality of life for many thousands of men with prostate cancer," Mason added.

Alastair Lamb, one of the authors of the study, said their results should be tested in bigger studies.

"The next step is to confirm these results in bigger studies and drill down into the molecular 'nuts and bolts' of each specific prostate cancer type," Lamb said, according to The Guardian. "By carrying out more research into how the different diseases behave we might be able to develop more effective ways to treat prostate cancer patients in the future, saving more lives."

The study was published recently in the journal EbioMedicine.