Intermittent androgen suppression in prostate cancer: an update of the Vancouver experience.
Bibliographic record
Abstract
INTRODUCTION: This report will review the long-term follow-up of a prospective Phase II evaluation of intermittent androgen suppression in the treatment of prostate cancer. Specifically, this analysis will address completed cycle characteristics, the concept of prolonged off-treatment cycles, the time to cancer progression, cancer-specific survival and the association between PSA and bone scan changes. METHODS: A total of 102 patients have been entered into this protocol. Treatment was initiated with combined androgen blockade and continued for 6 months or longer to reach a serum PSA nadir. Medication was then withheld until the serum PSA increased to predetermined trigger points based on initial parameters. Each cycle of treatment and no-treatment was repeated until the regulation of PSA became biochemically androgen independent. RESULTS: One hundred two patients have been commenced on IAS with an average follow-up time of 219 weeks (range: 14.5 to 588). Ninety-one patients have completed at least one therapeutic cycle with a total of 188 completed cycles available for analysis. The average time off therapy (percentage time off therapy) for cycles 1, 2, 3 and 4 was 13 months (53%), 11 months (51%), 10 months (47%) and 8 months (45%), respectively. A prolonged off-treatment time of greater than 72 weeks was observed in 33 (18%) of all completed cycles, and was most common in the men being treated for radiation failure stage C. Progression and survival data was calculated for the entire trial cohort (n=102). The average time to androgen independent progression in the 29 (28%) patients who progressed was 194 weeks. Death from prostate cancer occurred in 19 (18%) patients at an average of 258 weeks following treatment initiation. A review of bone scans revealed 22 events of newly detected lesions, all but 2 of which were preceded by a rise in serum PSA. CONCLUSIONS: Longer duration follow-up of a single cohort continues to support IAS as a viable treatment option for men with prostate cancer. This approach affords an improved quality of life when the patient is off therapy, with reduced toxicity and costs. There is a trend toward extended times to progression and death compared to contemporary studies of continuous androgen suppression. Randomized, prospective protocols are currently underway to determine whether survival is affected in a beneficial or adverse way in men with locally recurrent or metastatic cancer.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".