Prognostic Impact of Hyperthermic Intraperitoneal Chemotherapy After Laparoscopic Gastrectomy in Gastric Cancer with Positive Peritoneal Lavage Cytology and no Other Noncurative Factors.

BACKGROUND

This study was designed to evaluate the prognostic impact of laparoscopic gastrectomy combined with postoperative hyperthermic intraperitoneal chemotherapy (HIPEC) in gastric cancer patients exhibiting positive peritoneal lavage cytology (CY1) without visible metastases.

METHODS

Data from 263 patients undergoing peritoneal lavage cytology and laparoscopic gastrectomy between December 2017 and December 2022 were retrospectively analyzed. Patients were stratified into CY1 (positive cytology) or CY0 (negative cytology) groups, with CY1 cases further subdivided into HIPEC and non-HIPEC cohorts based on postoperative HIPEC administration. Postoperative recurrence and survival outcomes were compared across cohorts.

RESULTS

Among 263 patients, 214 were CY0 and 49 CY1 with 27 CY1 patients receiving HIPEC and 22 non-HIPEC. HIPEC-treated CY1 patients demonstrated lower postoperative recurrence (66.7% vs. 90.9%) and visible peritoneal metastasis rates (29.6% vs. 59.1%) than non-HIPEC counterparts (P < 0.05). CY0 patients exhibited higher 3-year overall survival (OS) and progression-free survival (PFS) rates compared with both non-HIPEC CY1 and HIPEC-treated CY1 subgroups. HIPEC-treated CY1 patients showed superior 3-year OS (51.8% vs. 18.2%, P = 0.005) and PFS (35% vs. 13.6%, P = 0.037) than non-HIPEC CY1. Notably, stage III CY0 cohort demonstrated comparable survival outcomes to HIPEC-treated CY1 cohort (overall survival 56.4% vs. 51.8%, P = 0.39; progression-free survival 51% vs. 35%, P = 0.14). Cox analysis identified non-HIPEC and pN2-3 stage as independent risk factors for OS, while non-HIPEC, pT4, and pN2-3 stages predicted poorer PFS in CY1 patients.

CONCLUSIONS

Hyperthermic intraperitoneal chemotherapy following laparoscopic gastrectomy demonstrated efficacy in reducing postoperative peritoneal metastasis rates while enhancing prognosis of CY1 patients, achieving oncologic outcomes comparable to stage III CY0 counterparts, although additional investigation remains imperative.