CT-detected extramural venous invasion is corelated with presence of lymph node metastasis and progression-free survival in gastric cancer.

OBJECTIVE

This study aimed to investigate if CT-detected extramural venous invasion (ctEMVI) was associated with the presence of lymph node metastasis (LNM) and survival outcomes in patients with gastric cancer.

METHODS

We retrospectively reviewed 105 patients with pathologically proved gastric cancer who underwent pre-operative CT examinations and received radical gastrectomy with extended lymphadenectomy. Differences in CT characteristics between the LNM-positive and -negative groups were assessed by two observers. Binary logistic regression analysis was performed to determine the risk factors of lymph node metastasis in gastric cancer. Progression-free survival analysis was performed by Kaplan-Meier method.

RESULTS

Two observers reached good inter-reader agreements in ctEMVI and ctN status with κ values of 0.711 and 0.751, respectively. The frequency of ctEMVI-positive status was 58.1% (61/105) in patients with gastric cancer. The LNM-positive group showed higher possibility of ctEMVI-positive status (81.7% 26.7%, ＜0.001), larger tumor volume (mean volume, 40.77 22.09 mL, ＜0.001), poor tumor margin (45.0% 26.7% , = 0.054) and high enhancement on arterial phase (43.3% 26.7%, = 0.023) and venous phase (60.0% 44.4%, = 0.048), than LNM-negative group. In multivariate analysis, ctEMVI status and tumor volume were identified as independent risk factors for lymph node metastasis with odds ratio (OR) of 9.804 (95% CI, 3.076－31.246; ＜0.001) and 1.030 (95% CI, 1.001－1.060; = 0.044). CT-detected EMVI presented better diagnostic efficiency for lymph node metastasis than CT-defined N status, with sensitivity (81.7% 70.0%), specificity (73.3% 71.1%), accuracy (78.1% 70.5), PPV (80.3% 76.4%), and NPV (75.0% 64.0%), respectively. Kaplan-Meier curves showed that patients with positive ctEMVI findings has lower PFS rate than patients with negative ctEMVI findings (Log-rank test, = 0.007).

CONCLUSION

CT-detected EMVI was significantly associated with lymph node metastasis and progression free survival in patients with gastric cancer. Compared to CT-defined N status, ctEMVI provided superior diagnostic performance to predict pathologic Nstatus.

ADVANCES IN KNOWLEDGE

Our study proved that CT-detected EMVI is a promising imaging marker to predict lymph node metastasis and poor prognosis, which may contribute to the precise evaluation of gastric cancer before surgery.