Value of transrectal prostatic echography, prostate-specific antigen and rectal examination in the diagnosis of prostate cancer. Relationship with the result of prostatic biopsies.

Unlabelled: We retrospectively reviewed the files of patients who had undergone a prostatic biopsy between July 1992 and December 1994. A total of 368 biopsies of 340 patients between 36 and 89 years old, could be used. The pathological examination was used to make the diagnosis of prostate cancer. The specificity and sensitivity values of the diagnostic examinations (TRUS, DRE, PSA and PSAD) were calculated. An abnormal TRUS image (hypodens or hyperdens area or irregular prostate) has the best sensitivity: 91.3%. PSA has the best specificity: 57.2%. The specificity and sensitivity of PSA can be improved by using the PSAD: a PSAD limit of 0.15 has a specificity of 66.4% and a sensitivity of 88.9%. The specificity and sensitivity values are also calculated for several combinations of tests. The combination of abnormal DRE or PSAD higher than 0.15 has a sensitivity of 96.2% and a specificity of 35.0%.

Conclusion: the combination of abnormal DRE or high PSAD has a high sensitivity with a relatively good specificity. We advise to take biopsy if two or more of the examinations are suspect or if one of them is clearly abnormal.