ToPCaP

Swedish Cohorts

Swedish Cohorts

The Swedish Case Control Study is nested in a tissue-based cohort of men who were treated between 1979-1997 at Örebro University Hospital in Sweden for BPH with TURP found to be benign. Some of these men were later diagnosed with prostate cancer by subsequent TURP or biopsy. For efficiency, we have designed a case-control study. Cases include 182 men diagnosed with prostate cancer following the initial, benign TURP. The median time between the initial TURP and prostate cancer diagnosis among the cases is ten years. Controls are 366 men without prostate cancer diagnosis for a minimum of ten years after the initial TURP, matched to cases on age and TURP year in categories. We retrieved medical records and pathology reports to confirm the diagnosis of prostate cancer, and extracted clinical data including TNM clinical and pathological stage, PSA levels at diagnosis, and initial treatments. We have developed a unique tissue biorepository in the cohort, including pre-diagnostic TURP as well as the diagnostic TURP or biopsy for prostate cancer cases.

The Swedish Watchful Waiting Cohort includes men with localized prostate cancer diagnosed in Örebro (1977 to 1999) and South East (1987 to 1999) Health Care Regions of Sweden. Eligible patients have been identified through population-based prostate cancer quality data bases in these regions, and include men who were diagnosed with incidental prostate cancer through transurethral resection of the prostate (TURP) or adenoma enucleations, i.e. T1a-b tumors. In accordance with standard treatment protocols at the time, patients with early stage/localized prostate cancer were followed expectantly ("watchful waiting"). No PSA screening programs were in place at the time.

We have been able to trace tumor tissue specimens for 92% (1256/1367) of all the potentially eligible cases. Available H&E slides from each case were reviewed to identify all tissue specimens with tumor tissue slides and corresponding paraffin-embedded formalin-fixed blocks have subsequently been retrieved and re-viewed to confirm cancer status and to assess Gleason grade and other notable histopathologic features.