ESTRO 2024 - Abstract Book

S2175

Clinical - Upper GI

ESTRO 2024

Results:

The median follow-up time was 41.5 months (range, 6 – 144.8 months).Median OS was 80 months (SE: 17.564; 95% CI: 46.265 – 115.115) and median PFS was 16.5 months (SE: 16.581; 95% CI: 23.354 – 88.351). The 2- and 5-year OS and PFS were 77% and 53% and 64% and 49%, respectively. In univariate analysis, lower T and N stage, LN ratio<0.18, R0 resection, >45 Gy RT dose, and having a locoregional control were found to be positive prognostic for OS (p=0.005, P=0.001, p <0.01, p<0.01, p <0.01, p <0.01, respectively) and PFS (p=0.01, p=0.03, p<0.01, p<0.01, p<0.01, p<0.01, respectively). Additionally, distal tumor localization was associated with improved OS (p=0.03), and the absence of lympho-vascular invasion was associated with improved PFS (p=0.02). In multivariate analysis, tumor location (distal vs. proximal), pT classification (pT1-2 vs. pT3- 4), lymph node ratio (<0.18 vs. ≥ 0.18), and presence of local recurrence were independent prognostic factors for OS. Surgical margins and presence of local recurrence were prognostic for PFS (p=0.021, HR: 1.835, 95% CI: (1.097 – 3.069); p<0.01, HR: 3.129, 95% CI: 1.880 – 5.208). T classification, lymph node ratio, tumor localization, and the presence of local recurrence were the parameters used for the prognostic nomogram (Figure 1). Survival probabilities of 1-2 and 3 years were calculated.

Figure 1. Nomogram for predicting patients with gastric cancer who underwent adjuvant chemoradiotherapy with 1-year, 2-year and 3-year survival probabilities

Conclusion:

A novel nomogram was constructed encompassing the variables of lymph node ratio, T classification, tumor site, and local recurrence in gastric cancer patients who had adjuvant CRT. Our nomogram can be used for defining optimal follow-up intervals and identifying patients who are likely to derive benefits from adjuvant CRT.

Keywords: gastric cancer, nomogram, adjuvant radiotherapy