Cancer screening for the primary care physician.

Cancer screening guidelines are developed by numerous agencies. These guidelines are often conflicting leaving the primary care physician in a difficult position. He (she) is requested to choose the best test for his or her patients taking into consideration the principles of screening, the test cost and most importantly the patient's emotional and physical well-being. Screening for some cancers, like lung cancer, has been considered of no benefit. Other cancers, like breast, colon, cervix and prostate, have been the subject of numerous recommendations: For breast cancer, clinical examination and mammography are recommended every 1-2 years for women between 50 to 70 years. For cervical cancer, PAP smear is suggested every 1-3 years and for colorectal cancer, a yearly fecal occult blood, sigmoidoscopy or colonoscopy every 5-10 years. Annual serum prostate specific antigen (PSA) and digital rectal examination screening for prostate cancer are still controversial.