Blindly Trusting the Stage: The Therapeutic Consequences of Clinical Staging Inaccuracy in Gastric Cancer.

Abstract

BACKGROUND: This study aimed to quantify clinical staging accuracy rates and evaluated the consequences if treatment decisions were based solely on clinical stages. PATIENTS AND METHODS: This retrospective study included 931 patients with nonmetastatic gastric cancer who underwent upfront radical gastrectomy, allowing the postoperative pathological stage (pTNM) to serve as the definitive gold standard. We compared concordance rates for T, N, and overall stages, and simulated guideline-directed treatment decisions on the basis of Chinese Society of Clinical Oncology (CSCO) criteria to calculate treatment error rates. RESULTS: Clinical staging inaccuracy was significant: 38.9% (362/931) for T stage, 48.2% (449/931) for N stage, and 43.9% (409/931) for the comprehensive stage. Notably, 34.0% (317/931) of patients were understaged for N status, indicating a high prevalence of occult metastases. Consequently, blindly trusting clinical staging would have resulted in 17.4% (162/931) undertreatment and 28.1% (262/931) overtreatment. Specifically, 15.4% (6/39) of cT1aN0 cases that actually had deeper tumor invasion or lymph node metastasis would have received endoscopic treatment, thereby missing necessary lymphadenectomy. For clinically advanced cases (≥ cT2, n = 798), 26.8% (214/798) of patients eligible for upfront surgery would have received unnecessary neoadjuvant chemotherapy. CONCLUSIONS: Clinical staging is markedly inaccurate, exposing patients to a high risk of treatment error, particularly undertreatment in clinically early cases and overtreatment in advanced cases.