Lymph node metastases at the time of prostatectomy are an infrequent finding. The correlation of the pattern of nodal metastases with patient outcome has yet to be explored.

Lymph node positive prostatectomies were retrospectively reviewed. The presence of cribriform carcinoma (CC), intraductal carcinoma (IDC) and ISUP grade (G) were documented. The largest nodal metastasis was assessed for morphologic patterns present. G was assigned to the metastasis based on percentage morphologic patterns present. Statistical analysis used SPSS to assess disease specific survival (DSS), disease free survival (DFS) and distant metastasis free survival (DMFS).

110 cases were identified: G5 (n=52), G4 (n=8), G 3 (n=34), G2 (n=10), no G (n=6; treatment effect). IDC or CC was present in 103 (94%) specimens. >1 positive node correlated with worse DFS (p=0.012, hazard ratio HR=1.951, 95% confidence interval 1.142-3.331) and DMFS (p=0.009, HR=2.647, 95% CI 1.239-5.651). G in the prostate and nodal metastasis were poorly correlated (kappa= 0.073, p=0.195). The presence of pattern 5 was seen in 33 nodes (30%) and correlated with DFS (p=0.020, HR=1.903, 95% CI 1.091-3.320), DSS (p=0.021, HR=5.937, 95% CI 1.084-32.533) and DMFS (p=0.007, HR=2.695, 95% CI 1.269-5.726). Nodal cribriform pattern showed no prognostic correlation and pattern 3 metastasis showed a significant trend towards better outcome (DMFS p=0.033, HR=0.431, 95% CI 0.194-0.958).

IDC or CC is identified in 94% of node positive prostate cancers. Although G in the largest nodal metastasis has prognostic significance, its G does not reflect that of the primary prostatic adenocarcinoma. This article is protected by copyright. All rights reserved.

Histopathology. 2019 Jun 08 [Epub ahead of print]

Michelle R Downes, Bin Xu, Theo H van der Kwast

Division of Anatomic Pathology, Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada., Department of Pathology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, USA., Laboratory Medicine Program, University Health Network, 200 Elizabeth St, Toronto, ON, M5G 2C4, Canada.