Active Surveillance: The Canadian Experience With an "Inclusive Approach"
Bibliographic record
Abstract
Active surveillance has evolved to become a standard of care for favorable-risk prostate cancer. This is a summary of the rationale, method, and results of active surveillance beginning in 1995 with the first prospective trial of this approach. This was a prospective, single-arm cohort study. Patients were managed with an initial expectant approach. Definitive intervention was offered to those patients with a prostate-specific antigen (PSA) doubling time of less than 3 years, Gleason score progression (to 4+3 or greater), or unequivocal clinical progression. Survival analysis and Cox proportional hazard model were applied to the data. Since November 1995, 450 patients have been managed with active surveillance. The cohort included men under 70 with favorable-risk disease and men of age more than 70 with favorable- or intermediate-risk cancer (Gleason score 3+4 or PSA 10-15). Median follow-up is 6.8 years (range 1-16 years). Overall survival is 78.6%. Ten-year prostate cancer actuarial survival is 97.2%. Five of 450 patients (1.1%) have died of prostate cancer. Thirty percent of patients have been reclassified as higher-risk patients and offered definitive therapy. The commonest indication for treatment was a PSA doubling time less than 3 years (48%) or Gleason upgrading (26%). Of 117 patients treated radically, the PSA failure rate was 50%. This represents 13% of the total cohort. Most PSA failures occurred early; at 2 years, 44% of the treated patients had PSA failure. The hazard ratio for non-prostate cancer mortality to prostate cancer mortality was 18.6 at 10 years. In conclusion, we observed a very low rate of prostate cancer mortality in an intermediate time frame. Among the one-third of patients who were reclassified as higher risk and retreated, PSA failure was relatively common. However, other-cause mortality accounted for almost all of the deaths. Further studies are warranted to improve the identification of patients who harbor more aggressive disease in spite of favorable clinical parameters at diagnosis [reproduced from Klotz (1) with permission from Wolters Kluwer Health].
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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 | 0.008 | 0.011 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.005 | 0.003 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.003 | 0.004 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 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".