The prostate, a male reproductive gland, produces approximately one-third of the fluid in semen, according to the information website PSA Rising. In addition, the epithelial cells in the prostate secrete a protein known as prostate specific antigen, also called PSA. PSA keeps the semen in liquid form and nourishes and protects the sperm. Although most PSA remains in the ducts of the prostate, some leaks into the bloodstream, allowing doctors to utilize this protein as a marker for prostate conditions. Although a PSA test can help indicate diseases such as prostate cancer, the test is very sensitive and can give rise to false positive results, meaning that high PSA numbers could be due to other factors.
High PSA
Normally, only small amounts of PSA leak into the blood. Increased levels of PSA may indicate a problem within the prostate. Prostate cancer, the formation of a tumor due to the abnormal growth of cells in the prostate, causes PSA levels to rise. In general, doctors consider PSA levels of 4 nanograms/milliliter of blood as high, prompting them to perform additional testing on the prostate, according to MedlinePlus, a service of the National Institutes of Health. However, a high PSA number could be triggered by unrelated factors such as medications.
Cyclophosphamide
Doctors use cyclophosphamide, a chemotherapeutic agent, to treat many types of cancers including lymphoma, leukemia, multiple myeloma, neuroblastoma and retinoblastoma, according to the American Cancer Association. As an alkylating agent, cyclophosphamide targets rapidly dividing cells and damages the DNA in order to kill the cells. Cyclophophamide can also affect normal cells, resulting in numerous side effects. Lab Tests Online reports cyclophosphamide as one medication that can affect PSA readings, causing them to be too low or too high.
Methotrexate
Methotrexate, classified as an antimetabolite medication, slows the growth of cells. Doctors therefore prescribe it to treat conditions including psoriasis, rheumatoid arthritis and some forms of cancer. Methotrexate can act upon other cells within the body. Although the mechanism may remain unclear, methotrexate can affect PSA levels, resulting in high or low numbers, according to Lab Tests Online.
