Intestinal-type gastric cancer carries a better prognosis but a higher risk of lymph node metastasis than diffuse-type: a SEER study of nearly 28,000 patients

Abstract Background: The impact of Lauren type, namely intestinal and diffuse types, on prognosis and lymph node metastasis (LNM) for gastric cancer (GC), requires further exploration, since current samples are deficient and the results are inconsistent.We aimed to translate the widely used WHO classifications into Lauren types and analyze the impact with the largest sample size available.Methods: Corresponding Lauren types of the WHO classification system in the Surveillance, Epidemiology, and End Results (SEER) database were included to identify all patients with histological diagnoses of intestinal-type or diffuse-type GC.Results: 4,338 intestinal-type and 22,990 diffuse-type GC were included in our study. Compared with intestinal-type, diffuse-type had a relatively poor prognosis after adjustment for other risk factors (HR, 1.236; P<0.001). Similar to patients with all stages of GC, the prognosis of patients with early diffuse GC was also poor (HR, 1.295; P=0.001). Surgical operation and radiotherapy markedly improved the DSS for patients (P<0.05). To our surprise, the risk of intestinal LNM in all stages of GC was higher than that in the diffuse type (OR=0.891; P=0.036). Although, there was no positive correlation between LNM and Lauren’s GC (OR=1.096; P=0.467) in early stage.Conclusion: Intestinal-type GC carries a better prognosis but a higher risk of LNM than diffuse-type. Patients with intestinal-type GC are likely to gain a greater benefit from receiving surgical treatment, but it is worth noting that clinicians should pay more attention to their lymphatic metastasis.*Contributed equally.The first author: Chanqiong Zhang, Guangyu Chen