Abstract 5424
Background
Intraductal carcinoma of the prostate (IDC-P) is an adverse prognosticator of prostate cancer (PCa). However, the role of IDC-P proportion and architectural patterns in patient outcome remain unclear.
Methods
Data of 644 de novo metastatic PCa (mPCa) patients between 2010-2017 were retrospectively analyzed. IDC-P was identified from 12-core prostate biopsy. IDC-P proportion were calculated. IDC-P were classified into two architectural patterns according to the 2016 WHO classification: pattern-1 (loose cribriform or micropapillary) and pattern-2 (solid or dense cribriform). Propensity-score matching (PSM) was conducted to balance the baseline characteristics between patients with and without IDC-P. Kaplan-Meier curves and COX regression were utilized in survival analysis. The endpoints were castration-resistant PCa free survival (CFS) and overall survival (OS).
Results
Totally, 180/644 (28.0%) patients harboured IDC-P. IDC-P ≥10% (CFS: HR: 2.27, p < 0.001; OS: HR: 2.63, p < 0.001) and IDC-P pattern-2 (CFS: HR: 1.98, p < 0.001; OS: HR: 2.11, p = 0.003) were independently associated with worse prognosis in the post-PSM cohort. Based on these two risk factors, all men could be classified into five groups with significant differences in survival (Table 1). Patients in Group 0 (Without IDC-P) and IDC-P-Group 1 (IDC-P < 10% AND IDC-P pattern-1) had favorable mCFS (18.0- vs. 17.8-Mo, p = 0.663) and mOS (68.8-Mo vs. Not reached, p = 0.655), while men of IDC-P-Group 4 (IDC-P ≥ 10% AND IDC-P pattern-2) harboured the worst outcomes (mCFS: 8.4-Mo; mOS: 29.9-Mo). IDC-P-Group 2 (IDC-P < 10% AND IDC-P pattern-2; mCFS: 14.2-Mo; mOS: 45.9-Mo) and IDC-P-Group 3 (IDC-P ≥ 10% AND IDC-P pattern-1; mCFS: 11.9-Mo; mOS: 39.7-Mo) had intermediate prognosis.Table: 800P
The CFS for patients of different IDC-P groups and patients without IDC-P after propensity-score matching
| A. The survival outcomes for de novo mPCa patients of different IDC-P groups | |||||||
|---|---|---|---|---|---|---|---|
| IDC-P group | CASE | Median CFS (95%CI) | Log-rank test | ||||
| Group 0 | Group 1 | Group 2 | Group 3 | Group 4 | |||
| Group 0 | 180 (50.0%) | 17.8 (15.3-20.3) | - | 0.663 | 0.019 | 0.104 | 0.000 |
| IDC-P-Group 1 | 41 (11.4%) | 18.0 (12.7-23.2) | 0.663 | - | 0.194 | 0.264 | 0.001 |
| IDC-P-Group 2 | 58 (16.1%) | 14.2 (10.1-18.3) | 0.019 | 0.194 | - | 0.785 | 0.014 |
| IDC-P-Group 3 | 22 (6.1%) | 11.9 (6.0-17.8) | 0.104 | 0.264 | 0.785 | - | 0.080 |
| IDC-P-Group 4 | 59 (16.4%) | 8.4 (6.7-10.1) | 0.000 | 0.001 | 0.014 | 0.080 | - |
| IDC-P group | CASE | Median OS (95%CI) | Log-rank test | ||||
| Group 0 | Group 1 | Group 2 | Group 3 | Group 4 | |||
| Group 0 | 180 (50.0%) | 68.8 (58.9-78.7) | - | 0.655 | 0.098 | 0.028 | 0.000 |
| IDC-P-Group 1 | 41 (11.4%) | Not reached | 0.655 | - | 0.569 | 0.201 | 0.049 |
| IDC-P-Group 2 | 58 (16.1%) | 45.9 (29.7-62.1) | 0.098 | 0.569 | - | 0.530 | 0.061 |
| IDC-P-Group 3 | 22 (6.1%) | 39.7 (25.1-54.3) | 0.028 | 0.201 | 0.530 | - | 0.441 |
| IDC-P-Group 4 | 59 (16.4%) | 29.9 (20.7-39.2) | 0.000 | 0.049 | 0.061 | 0.441 | - |
| B. The survival outcomes for de novo mPCa patients of different risk group | |||||||
| Risk group | CASE | Median CFS (95%CI) | Log-rank test | ||||
| Group 1 or 0 | Group 2 or 3 | Group 4 | |||||
| Favorable-risk: Group 1 or 0 | 221 (61.4%) | 17.8 (15.5-20.1) | - | 0.009 | 0.000 | ||
| Intermediate-risk: Group 2 or 3 | 80 (22.2%) | 14.1 (10.3-17.9) | 0.009 | - | 0.007 | ||
| Poor-risk: Group 4 | 59 (16.4%) | 8.4 (6.7-10.1) | 0.000 | 0.007 | - | ||
| Risk group | CASE | Median OS (95%CI) | Log-rank test | ||||
| Group 1 or 0 | Group 2 or 3 | Group 4 | |||||
| Favorable-risk: Group 1 or 0 | 221 (61.4%) | 72.6 (63.8-72.6) | - | 0.027 | 0.000 | ||
| Intermediate-risk: Group 2 or 3 | 80 (22.2%) | 43.2 (35.2-51.1) | 0.027 | - | 0.080 | ||
| Poor-risk: Group 4 | 59 (16.4%) | 29.9 (20.7-39.2) | 0.000 | 0.080 | - |
CFS: CRPC-free survival; OS: Overall survival; IDC-P: Intraductal carcinoma of the prostate; CI: Confidence interval; mPCa: metastatic prostate cancer
Conclusions
IDC-P proportion ≥10% and pattern-2 were two unfavorable prognosticators for mPCa. Pathological reporting criterion based on IDC-P could further improve the prediction of patient outcome and optimize treatment decision.
Clinical trial identification
Legal entity responsible for the study
Department of Urology, Institute of Urology, West China Hospital, Sichuan University.
Funding
This work was supported by the National Natural Science Foundation of China (NSFC 81672547, 81402110, and 81272820); Science and Technology Support Program of Sichuan Province (2015SZ0142); The 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.