Association Between Kita-kyushu Lung Cancer Antigen-1 Expression in Gastric Cancer and Helicobacter pylori-infection Status

Abstract

Background/aim: Kita-kyushu lung cancer antigen-1 (KK-LC-1), a cancer/testis antigen (CTA), is frequently expressed in tumor and non-tumor sites of the stomach in patients with gastric cancer (GC). Additionally, KK-LC-1 has been associated with Helicobacter pylori (Hp) infection. Currently, the association between Hp eradication and GC incidence is unclear. This study aimed to investigate the association between KK-LC-1 expression and Hp eradication in GC.

Patients and methods: This study included 124 patients treated for gastric cancer. Pathological tissue from resected specimens was used to investigate KK-LC-1 expression in tumor and non-tumor sites. The association between 14 clinicopathological factors, including Hp infection and eradication, and KK-LC-1 expression was investigated and analyzed by Fisher's exact test and multivariable regression analysis.

Results: KK-LC-1 expression rate in cancerous tissues from patients with GC was 74.2%. The expression of KK-LC-1 was associated with older age, mucosal layer depth of invasion, differentiated type, no lymph node metastasis, Hp eradication, previous Hp infection, and multiple cancers.

Conclusion: KK-LC-1 expression was high in GC cases with previous Hp infection and successful eradication. KK-LC-1 expression pattern suggests that it may be associated with GC independently of Hp infection.

Keywords: Gastric cancer; Helicobacter pylori; atrophy; kita-kyushu lung cancer antigen-1.