Long‐term follow‐up of T1 high‐grade bladder cancer after intravesical bacille Calmette‐Guérin treatment
Bibliographic record
Abstract
Study Type – Therapy (cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? High‐grade non muscle invasive bladder cancer is a very aggressive disease, potentially lethal if not managed adequately, because of the ability of these tumours to invade surrounding tissues and become metastatic. Treatment with intravesical BCG has been shown to delay progression to muscle invasive or/and metastatic disease, preserve the bladder, and decrease the risk of death from bladder cancer. However, most studies have analyzed patients with short follow‐up, and long‐term data about the real efficacy of BCG to prevent tumour recurrence, progression and impact mortality are lacking. This study has analyzed a large series of patients with high‐grade non muscle invasive bladder cancer treated with intravesical BCG in two University Institutions (Toronto and Rotterdam), with a central pathology review by a very experienced uro‐pathologist. It provides further insight into the long‐term risks of progression of patients harbouring high‐grade T1 bladder cancer treated with BCG, demonstrating that about 30% of patients are at risk of progression and that late progressions even more than 3 years after the initial resection and BCG treatment are rare but not exceptional. OBJECTIVE To report the long‐term results of bacille Calmette‐Guérin (BCG) intravesical therapy in relation to disease progression and recurrence in primary T1 high‐grade (HG) bladder cancer (BC) confirmed by central pathological review. PATIENTS AND METHODS In all, 136 patients from two university centres (Rotterdam, n = 49; Toronto, n = 87) were diagnosed with primary T1HG BC. One experienced uro‐pathologist reviewed all slides, ensuring all cases were indeed HG and that muscle was present in all specimens. Patients were treated with BCG induction (six instillations) after transurethral resection (TUR) of the tumour and followed with cystoscopy and urinary cytology. Predictors for recurrence, progression and survival were assessed with multivariable Cox regression models. RESULTS Mean (range) follow‐up was 6.5 (0.3–21.6) years. There were no significant differences for recurrence ( P = 0.52), progression ( P = 0.35) and disease‐specific survival (DSS) ( P = 0.69) between the two centres. Among the cohort, 47 patients (35%) recurred and 42 (30.9%) progressed with a median time to progression of 2.1 years; 16 (38%) of these progressions occurred ≥3 years after the initial BCG course; 22 (16%) patients who progressed died from BC. Overall, 96 (71%) patients had no evidence of disease at the last follow‐up. Carcinoma in situ was the only independent predictor for recurrence in multivariate analysis ( P = 0.011). No independent predictors were found for progression. CONCLUSIONS Conservative treatment with BCG is a valid option in primary T1HG BC. Nevertheless, the aggressive nature of T1HG BC is evident in the fact that 30% progressed, with a high proportion of these progression events occurring ≥3 years after BCG. Caution should be exercised when relying on the long‐term effects of BCG, and close follow‐up of these patients should not be neglected.
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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 | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".