The recent changes in the American Joint Commission on Cancer-8th edition (AJCC-8E) pT2 and pT3 tumor definitions for penile cancer need robust validation studies. A recent study redefined and modified the pT2 and pT3 stages incorporating the histopathological variables (tumor grade, lymphovascular invasion, perineural invasion) similar to that used in the current AJCC-8E pT1 stage tumor subclassification. In this study, we validate and compare this proposed staging with the AJCC staging systems, on an external dataset.
The dataset from a previously published study was obtained. pT2 and pT3 stages were reconstructed as per AJCC 7th edition (AJCC-7E), AJCC-8E, and the proposed staging. The staging systems were correlated with nodal metastasis, disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS). All systems were compared using receiver operating characteristics (ROC) curves. A total of 281 cases formed the study cohort. AJCC-8E (p=0.031) and the proposed staging (p=0.003) correlated with nodal metastasis on adjusted analysis, the latter with a better strength of association (AJCC-8E, γ= -.471, proposed, γ= -.625). On adjusted analysis, all the staging systems had a significant correlation with DFS, while only AJCC-8E and the proposed staging correlated with CSS and OS. On ROC curve analysis, the proposed staging had the highest area under the curve and was the only staging system to statistically correlate with all the outcome variables.
The proposed staging for pT2/pT3 tumor stages in penile cancer may improve the prognostic and predictive ability.
Histopathology. 2021 Sep 29 [Epub ahead of print]
Akash P Sali, Gagan Prakash, Stênio de Cássio Zequi, Walter H da Costa, Vedang Murthy, Fernando A Soares, Ganesh Bakshi, Gustavo C Guimarães, Amit Joshi, Mahendra Pal, Sangeeta B Desai, Antonio L Cubilla, Santosh Menon
Department of Pathology, Homi Bhabha Cancer Hospital (A unit of Tata Memorial Centre), Sangrur, Punjab, India, 148001., Department of Surgical Oncology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India, 400012., Department of Urology, AC Camargo Cancer Center, São Paulo, Brazil, 01508-010., Department of Radiation Oncology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India, 400012., D'Or Institute for Research and Education (IDOR), São Paulo, Brazil., Department of Surgical Oncology, BP - A Beneficência Portuguesa de São Paulo, São Paulo, Brazil, 01323., Department of Medical Oncology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India, 400012., Department of Pathology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India, 400012., Department of Pathology, Instituto de Patologia e Investigacion, Asuncion, Paraguay.