Active surveillance in Canadian men with low-grade prostate cancer
Bibliographic record
Abstract
BACKGROUND: Recent guidelines recommend against routine screening for prostate cancer, partly because of the risks associated with overtreatment of clinically indolent tumours. We aimed to determine the proportion of patients whose low-grade prostate cancer was managed by active surveillance instead of immediate treatment. METHODS: We reviewed data for patients who were referred to the Ottawa regional Prostate Cancer Assessment Clinic with abnormal results for prostate-specific antigen (PSA) or prostate examination between Apr. 1, 2008, and Jan. 31, 2013. Patients with subsequent biopsy-proven low-grade (Gleason score 6) cancer were included. Active surveillance was defined a priori as monitoring by means of PSA, digital rectal examination and repeat biopsies, with the potential for curative-intent treatment in the event of disease progression. RESULTS: Of 477 patients with low-grade cancer, active surveillance was used for 210 (44.0%), and the annual proportion increased from 32% (11/34) in 2008 to 67% (20/30) in 2013. Factors associated with immediate treatment were palpable tumour, PSA density above 0.2 ng/mL(2) and more than 2 positive biopsy cores. Factors associated with surveillance were age over 70 years and higher Charlson comorbidity index. Of 173 men who received immediate surgical treatment, 103 (59.5%) had higher-grade or advanced-stage disease on final pathologic examination. Of the 210 men with active surveillance, 62 (29.5%) received treatment within a median of 1.3 years, most commonly (52 [84%]) because of upgrading of disease on the basis of surveillance biopsy. INTERPRETATION: Active surveillance has become the most common management strategy for men with low-grade prostate cancer at our regional diagnostic centre. Factors associated with immediate treatment reflected those that increase the risk of higher-grade tumours.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".