Clinical characteristics of gastrointestinal stromal tumors with lymph node metastasis: a retrospective single-center study.

Background: Lymph node metastasis (LNM) of gastrointestinal stromal tumors (GISTs) rarely occurs, and lymphadenectomy is not routinely performed in GIST resection. To date, the relevant characteristics and prognosis of GIST patients with LNM are not well known.

Methods: From January 2010 to December 2021, GIST patients who underwent lymph node resection were enrolled from a GIST referral center. All patients were divided into either the LN- group (GISTs without LNM) or the LN+ group (GISTs with LNM). The clinicopathological features and follow-up data were analyzed. Propensity score matching (PSM) was conducted to reduce bias caused by confounders.

Results: Out of 1024 surgical patients, 198 patients (age, 52.23 ± 13.54 years; 56.6% males) underwent GIST resection with lymph node dissection for lymphadenopathy, and 17 patients had lymph node metastases (17/1024, 1.66%; 17/198, 8.59%). The LN+ group had a higher mitotic count (p = 0.012) and a higher proportion of distant metastasis (p < 0.001) than the LN- group. After PSM, 28 patients were included (18 in LN- group and 10 in LN+ group). The LN- group had both longer postoperative progression-free survival (PFS, not reached vs. 15.0 months, p = 0.002) and overall survival (OS) than the LN+ group, but the difference in OS was not statistically significant (not reached vs. 35.0 months, p = 0.069).

Conclusions: The rate of LNM in GISTs is low. LNM may be a less common form of distant metastasis. Moreover, GIST with LNM has an unfavorable prognosis. Further studies are warranted to identify GISTs with lymph node involvement and the potential involved mechanism.