Metrics of pN-staging in oral squamous cell carcinoma: An analysis of 1, 905 patients. (June 2021)

• Record Type: Journal Article
• Authors: Mirian, Christian; Gerds, Thomas A.; Pedersen, Maria M.; de Ridder, Mischa; Balm, Alfons; Mattavelli, Davide; Piazza, Cesare; Jensen, Lasse R.; Balasubramanian, Deepak; Subramaniam, Narayana; Dokhe, Yogesh; Thankappan, Krishnakumar; Iyer, Subramania; Karam, Sana D.; Wiegand, Susanne; Feeley, Linda; Milross, Chris; Gao, Kan; Palme, Carsten E.; Low, Tsu-Hui (Hubert); Gupta, Ruta; Freudlsperger, Christian; Moratin, Julius; Sheahan, Patrick; Clark, Jonathan; Ovesen, Therese
• Is Part Of: European journal of cancer. Volume 150(2021)
• Page Start: 33
• Page End: 41
• Publication Date: 2021-06
• Subjects: Oral oncology -- OSCC -- Head and neck oncology -- TNM -- AJCC -- Classification -- pN-staging -- Lymph nodal yield -- Lymph nodal density -- Epidemiology; Cancer -- Periodicals; Neoplasms -- Periodicals; Cancer -- Périodiques; Cancer; Tumors; Electronic journals; Periodicals; Electronic journals; 616.994
• DOI: 10.1016/j.ejca.2021.03.019
• Languages: English
• ISSNs: 0959-8049

Abstract

Abstract: Background: We aimed to compare the predictive performance of pN-categories in oral squamous cell carcinoma (OSCC) encompassing the most recent 8th edition (TNM8), its predecessor (TNM7), and a newly proposed algorithm (pN-N + ), which classifies patients according to the number of positive lymph nodes and extranodal extension. Methods: Consecutive, primary OSCC patients from seven previously published cohorts were included and classified according to the three pN-classifications: TNM7, TNM8 and pN-N + . Overall survival probabilities were summarised with the Kaplan–Meier method. We added each of the three metrics to a Cox regression adjusted for pT-category, lymph nodal yield, age, sex, radiotherapy and chemotherapy, and trained these models in one institution. We evaluated the predictive performance in the remaining six institutions and assessed the predicted 5-year risk of death using the area under the receiver operating characteristics curve (AUC) and Brier scores. Results: All 1, 905 included patients were classified according to TNM7 and pN-N + . A subset of 1, 575 patients was additionally classified according to TNM8, leading to upstaging in 27.0%. The pN-N + ranked overall best determined by the obtained AUC and Brier scores. In contrast to pN-N +, TNM7 and TNM8 both suffered from disproportionate patient distribution across pN-categories and poor pN-categorial discrimination on overall survival. Conclusions: The TNM8 pN-classification designates a larger subset to more advanced disease stages but failed to show improvement of its predictive performance compared to TNM7. The pN-categories of TNM7/8 are disproportionate and inconsistently discriminated. The pN-N + conveyed the best measures of prognosis and should be considered in future TNM iterations. Highlights: The TNM8 pN-classification of OSCC has not improved compared to its predecessor. The TNM8 pN-classifications allocates more patients to advanced stages. The pN-categories of TNM8 are disproportionate and poorly discriminates risks. Number of pN+ and extranodal extension conveyed best measures of prognosis. The metastatic burden should be considered in future TNM iterations.