All men age 50 and older should be tested annually for prostate cancer.There are currently two types of prostate cancer screening. The prostate-specific antigen (PSA) test and the digital (finger) rectal exam.

The first test measures the level of PSA in the blood. PSA is a substance made mostly by the prostate. Too much PSA in the blood may indicate prostate cancer. However, high levels of PSA may also be indicative of infection, inflammation or an enlarged prostate.

The second test involves a doctor or nurse placing a lubricated, gloved finger into the rectum to check the prostate for lumps and anything else unusual.

If either test raises a red flag, doctors may follow up with a prostate biopsy. This is currently the most accurate way of checking for cancer. While complications from the biopsy are relatively rare, they can result in a urinary tract infection, as well as urinary and incontinence problems. In the United States, only an estimated 15% of patients who undergo a biopsy actually are diagnosed with prostate cancer, while each biopsy costs over $1,000.

Other non invasive tests are being developed to elleviate patient anxiety and discomfort.Improving identification of patients with a high probability of prostate cancer would reduce the number of unnecessary biopsies.

In November 2008, Italian researchers announced two proteins in the blood that can give the earliest warning yet of prostate cancer.

The four researchers from Catania University and Milan's Tumour Institute say an unexplained rise in the proteins osteopontin and metalloprotease-9 is a ''probable'' sign of a prostate tumour developing. The Italian team says the new protein duo can catch it quicker than current testing methods.

The head of the Biomedical Research Department at Catania University, Franca Stivala, said the results were ''promising'' but needed further testing.The study was published in the journal Clinical Cancer Research.

In October 2008, French in vitro diagnostics company bioMérieux partnered with German biotechnology company ProteoSys for its novel prostate cancer marker Annexin 3, which will be used to develop a non invasive, urine test for prostate cancer with high a specificity for prostate cancer.

Annexin 3, also known as ANXA 3, was discovered by ProteoSys. After a research phase, the new test should be developed on the VIDAS platform, one of the most widely installed automated immunoassay instruments in the world. The ANXA 3 test will be complementary to the tPSA and FPSA tests already available on VIDAS.