In 2005, the International Society of Urologic Pathology consensus conference recommended that men with biopsy Gleason score 3 + 4 or 4 + 3 prostate cancer with a tertiary pattern 5 should have their cancer classified as Gleason score 8 or 9 respectively. Yet, the approach to the management of men with Gleason score 7 as compared to 8 or 9 prostate cancer differs. We performed this study to see if we were able to provide evidence to support this practice-changing recommendation based on recurrence data following standards of care.
Materials/Methods
From 1989 to 2005, 2370 men of median age 66 (interquartile range: 59–72) years with clinical tumor category 1c to 3b, node negative and non-metastatic adenocarcinoma of the prostate underwent radical prostatectomy or external beam radiotherapy with or without androgen suppression therapy for prostate cancer at Harvard affiliated institutions. A pathologist who has expertise in cancers of the genitourinary tract assigned Gleason scores to the prostate needle biopsy specimens. Cox regression multivariable analysis was used to assess whether a significant association existed between the presence of tertiary grade 5 in men with Gleason score 7 prostate cancer and time to recurrence as compared to men with Gleason score 7 without tertiary grade 5 and men with Gleason score 5 to 6 or 8 to 10 disease adjusting for known prognostic factors.
Results
After a median follow-up of 4.2 (interquartile range: 1.8–6.7) years and adjusting for known prognostic factors, men with a biopsy Gleason score 7 prostate cancer and tertiary grade 5 had a significantly shorter time to PSA failure than men with Gleason score 7 without tertiary grade 5 (HR: 0.58, 95% CI: 0.34–0.98, p = 0.04) and men with Gleason score 6 or less (HR: 0.29, 95% CI: 0.17–0.50, p < 0.001). There was no significant difference in time to PSA failure when men with Gleason score 7 and tertiary grade 5 were compared to men with Gleason score 8 to 10 disease (HR: 0.87, 95% CI: 0.51–1.5, p = 0.62).
Conclusions
These results support the International Society of Urologic Pathology consensus conference statement and provide evidence to support recommending the same treatment options to men whose prostate needle biopsies reveal either Gleason score 7 and tertiary grade 5 or Gleason score 8 to 10 cancer.
1Brigham & Women's Hospital/Dana-Farber Cancer Institute, Boston, MA
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