Recurrence and 5-FU sensitivity of stage II/III node-positive gastric cancer with occult neoplastic cells in lymph node sinuses.

The 5-year overall survival (OS) rates for patients without occult neoplastic cells (ONCs) were 43.0% in stage II (n=15), 52.2% in stage III (n=23), and 48.5% for stages II and III combined (n=38). For ONC-positive patients, the 5-year OS rates were 44.4% in stage II (n=7; p=0.88322), 11.3% in stage III (n=30; p=0.0006), and 17.5% for stages II and III combined (n=37; p=0.0019). Among the ONC(+) recurrence group (75.7%, 28/37), 42.9% (12/28) showed high TS expression in metastatic lymph nodes and 57.1% (16/28) showed low TS expression. In the case of DPD expression, 32.1% (9/28) showed high expression and 67.9% (19/28) showed low expression. Among the ONC(+) non-recurrence group (24.3%, 9/37), 66.7% (6/9) showed high TS expression and 33.3% (3/9) showed low TS expression, while high and low DPD expression was seen in 22.2% (2/9) and 77.8% (7/9), respectively. A combination of high TS and low DPD expression was found in 32.1% (9/28) of the recurrence group vs. 66.7% (6/9) of the non-recurrence group (p=0.070). These results suggest that ONCs are associated with OS. Unlike the non-recurrence group, the ONC(+) patients with recurrence of stage II/III node-positive gastric cancer are unlikely to respond to treatment with 5-FU + LV and may need combination chemotherapy based on L-OHP and/or CPT-11.