Interpolation to define clinical tumor stage in prostate cancer using clinical description of digital rectal examination.

Abstract

This study aims to assess characteristics of patients with prostate cancer for whom clinical T stage category (cT) was not documented in the medical record and assess whether specialists had concordant conclusions regarding cT based on digital rectal examination (DRE) notes. Data from the Prostate Cancer Outcome Registry - Victoria (PCOR-Vic) were interrogated. Four specialists independently assigned cT to DRE notes. Words, or part thereof, associated with agreement between clinicians were identified. Of the 10 587 men, cT was documented in 8758 (82.7%) cases. Multivariate analysis indicated that poor cT documentation was associated with older patient age (odds ratio [OR] 0.80, 95% confidence interval [CI] 0.66-0.99 if 75.1-85 years; OR 0.50, 95%CI 0.36-0.72 if >85 years); diagnosis via transperineal compared to transrectal ultrasound-guided biopsy (TRUS) (OR 0.68, 95%CI 0.51-0.91); diagnosed in a private hospital (OR 0.85, 95%CI 0.75-0.96); and a diagnostic Gleason score of >8 compared to ≤6 (OR 0.59, 95%CI = 0.48-0.73). cT was more likely documented in men diagnosed via transurethral resection of prostate (OR 2.06, 95%CI 1.64-2.58) compared to TRUS and/or if receiving treatment in a radiotherapy center (OR 3.44, 95%CI 2.80-4.23 for external beam radiotherapy; OR 3.57 95%CI 2.44-5.23 for brachytherapy and OR 1.34, 95%CI 1.06-1.69 for combination surgery and radiotherapy) compared to those undergoing radical prostatectomy. Agreement in cT assignment ranged from kappa of 0.158 to 0.582. Stem word components in DRE notes associated with poorest level of agreement were "abnorm," "hard," "nodul" and those with highest level of agreement were terms "benign" and "smooth." Mode of diagnosis/subsequent treatment, and cancer characteristics were associated with cT documentation. Third party interpretation of clinical notes is problematic.