Baseline Prostate-Specific Antigen Level and Risk of Prostate Cancer and Prostate-Specific Mortality: Diagnosis Is Dependent on the Intensity of Investigation

Abstract

Background: When considering prostate biopsy, men and their physicians must balance the potential benefits of early diagnosis of localized cancer with the implications of overdiagnosis of clinically insignificant cancers. We investigated the risk of prostate cancer and prostate cancer -specific and allcause mortality by baseline prostate-specific antigen (PSA) level in a population-based cohort study in Northern Ireland, where PSA screening is not recommended and where low to moderately raised (<10.0 ng/mL) PSA levels were not routinely investigated. Methods: From a regional electronic database of PSA results, men who had their initial PSA between January 1, 1994 and December 31, 1998 were identified and followed for diagnosis of prostate cancer and prostate cancer -specific and all-cause mortality until December 31, 2003.

Repeating an abnormal prostate-specific antigen (PSA) level: how relevant is a decrease in PSA?

“…7,8 Briefly, data on all men undergoing PSA testing in Northern Ireland (NI) are maintained on a central electronic database. Using unique identifiers (name, date of birth and address), PSA results are matched to identify repeat tests for each individual.…”

“…Many men with PSA levels X4.0 ng ml À1 did not proceed to prostate biopsy; this is in keeping with the practice relating to PSA testing in Northern Ireland in the 1990s, where men tended to be investigated only if their PSA increased to X10.0 ng ml À1 . 8 The PSA changes and cancer diagnosis rate observed may have differed if all men had undergone prostate biopsy. Further, the decision to proceed to prostate biopsy and the biopsy technique used were not standardized and were at the discretion of each individual's clinician.…”

Daily, monthly and seasonal variation in PSA levels and the association with weather parameters

“…Further, previous analyses of the NI PSA database have not shown any systematic bias in PSA results from any laboratory. [9][10][11] Other limitations of the data in the NI PSA database have previously been discussed. [9][10][11] In addition, regional weather data only are presented.…”

“…[9][10][11] Other limitations of the data in the NI PSA database have previously been discussed. [9][10][11] In addition, regional weather data only are presented. NI is a small region with similar weather patterns throughout the province; therefore, local differences in weather parameters are unlikely to be significant.…”

“…[9][10][11] Initial PSA data only were included, whereas men with a previous diagnosis of prostate cancer were excluded.…”