Presentation Authors: Li Zaishang, Shenzhen, China, People's Republic of, Han Hui*, Zhou Fangjian, Guangzhou, China, People's Republic of
Introduction: The 8th American Joint Committee on Cancer tumor-node-metastasis (AJCC-TNM) staging systemis based on a few retrospective single-center studies. We aimed to test the prognostic validity of the classiï¬cation and to determine whether a modified pathological tumor stage that includes lymphovascular embolization could increase the prognostic accuracy for T2-3 stage penile cancer.
Methods: A training cohort of 411 patients who were treated at 2 centers in China and Brazil between 2000 and 2015 were staged..Data from 436 patients who were treated at 15 centers over four continents were used for external validation.A modified staging system was proposed. In this system, we subdivided the T2 and pT3 ategories of the 8th TNM system into two new categories as follows: t2 tumors invade the corpus spongiosum and/or corpora cavernosa and/or urethra without lymphovascular invasion, and t3 tumors invade the corpus spongiosum and/or corpora cavernosa and/or urethra with lymphovascular invasion.
Results: A survivorship overlap was observed between T2 and T3 patients (P=0.587) in the 8th staging system. Lymphovascular embolization was a significant prognostic factors for metastasis and survival (all P < 0.001). Based on the multivariate analysis (after accounting for confounding variables), only lymphovascular embolization showed a signiï¬cant inï¬‚uence on cancer-specific survival (CSS) (hazard ratio 1.587, 95% confidence interval CI 1.253-2.011; P=0.001). By including lymphovascular embolization with the pathological staging, patients with T2 and T3 tumors (8th) showed significantly increased differences in survival (P < 0.001). The Kaplan-Meier plots of this modified stage grouping showed significant differences between individual stages without crossing curves (all P < 0.005). These modified criteria exhibited better accuracy in predicting patient prognoses (C-index, 0.739) than the 8th AJCC-TNM criteria (C-index, 0.696). These results were conï¬rmed using external validation cohorts.
Conclusions: Carcinomas of the T2-3 subgroup are heterogeneous, and a modified pathological staging system that incorporates lymphovascular embolization may better reflect the prognosis of patients with penile cancer.