The Discordance of Clinical and Pathologic Staging in Locally Advanced Gastric Adenocarcinoma.

BACKGROUND

Clinical staging guides decisions about optimal treatment sequence in patients with gastric cancer, although the preoperative accuracy is not strongly established. This study investigates concordance of clinical and pathologic stage as well as its impact on the survival of patients with gastric adenocarcinoma.

METHODS

Patients with clinical stage T2-4, N0, M0 gastric adenocarcinoma who underwent surgery without neoadjuvant therapy were identified from the National Cancer Database (2010-2015). The primary outcome was up-staging, defined as cT < pT, pN1-3, and/or pM1 (AJCC 7 edition). Multivariable logistic regression analysis was performed to predict up-staging. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

In total, 2254 patients were identified. cTNM staging was discordant with pTNM staging in 65.6% of cases, with 50.4% up-staged and 15.2% down-staged. On multivariable logistic regression, younger age (OR 0.991, 95% CI 0.984-0.999, p=0.0188), male sex (versus female; OR 1.392, 95% CI 1.158-1.673, p=0.0004), poor or undifferentiated tumor grade (versus well differentiated or moderately differentiated; OR 2.399, 95% CI 1.987-2.896; p<0.0001), positive margin status (versus negative; OR 4.575, 95% CI 3.360-6.230; p<0.0001), and days from diagnosis to surgery (15-32 days versus ≤ 14 days; OR 1.411, 95% CI 1.098-1.814, p=0.0072) were predictive of up-staging. Patients who were up-staged had a decreased survival compared to patients who were accurately staged (median survival 27.9 months versus 67.6 months; log-rank p<0.0001).

CONCLUSION

This study found a substantial discordance between clinical and pathologic staging of resectable locally advanced gastric adenocarcinoma. These data support that patients may have more advanced disease at presentation than reflected in clinical staging and may benefit from improved diagnostic modalities and neoadjuvant chemotherapy.