Presence or absence of a positive pathological margin outperforms any other margin-associated variable in predicting clinically relevant biochemical recurrence in Gleason 7 prostate cancer
What's known on the subject? and What does the study add?
- The presence of a positive pathological margin is an independent risk factor for clinically significant disease recurrence only in intermediate-risk disease when the a priori risk of micrometastatic disease is accounted for.
- The study examines patients with Gleason 7 prostate cancer to assess the relative importance of various margin-related variables (focality, linear length, tumour grade at margin, presence of diathermy artifact and plane of tumour) with regard to biochemical recurrence. We found that the presence or absence of a positive pathological margin outperforms any other margin-associated variable in predicting significant disease recurrence.
- To determine the influence of pathological margin variables on the risk of clinically significant biochemical recurrence in Gleason 7 prostate cancer.
Materials and Methods
- Patients with Gleason 7 prostate cancer with complete clinical and pathological data and detailed follow-up were identified from a prospectively recorded prostatectomy database.
- Slides from all patients with positive pathological margins were reviewed by a single expert uropathologist and the following information recorded: multifocality, linear length, predominant Gleason grade at the margin, diathermy artifact and margin plane.
- Cox regression models were generated to determine the impact of positive pathological margins on the risk of biochemical recurrence (using various definitions thereof).
- Of 1048 patients with Gleason 7 prostate cancer, 238 (23%) patients had positive margins.
- With a median follow-up of 11 months, biochemical recurrence occurred in 9.7% of patients with negative surgical margins and 28.4% of patients with positive margins.
- Positive margins were significantly associated with higher serum prostate-specific antigen (PSA) level, tumour grade, stage and volume.
- In patients with positive pathological margins, controlling for other factors, no margin-derived variable (focality, linear length, tumour grade at margin, diathermy artifact or plane of tumour) was a consistent predictor of biochemical recurrence, although the presence of Gleason score 4 or tertiary Gleason score 5 tumour at the margin edge was an independent predictor of recurrence with PSA doubling times ≤ 6 and ≤9 months.
- Similarly, in the cohort as a whole, the pathological margin status was a more important predictor of recurrence than any other margin-derived variable.
- In Gleason 7 prostate cancer, positive pathological margin status was the only consistent margin-derived variable determining biochemical failure.
- The presence of high-grade disease at the margin may also have an impact on the development of clinically significant biochemical recurrence.