PT  - JOURNAL ARTICLE
AU  - Daisuke Kiyozawa
AU  - Kenichi Kohashi
AU  - Dai Takamatsu
AU  - Shinya Umekita
AU  - Masatoshi Eto
AU  - Mitsuru Kinjo
AU  - Kenichi Nishiyama
AU  - Kenichi Taguchi
AU  - Yumi Oshiro
AU  - Yusuke Kuboyama
AU  - Yoshinao Oda
TI  - Comparative analyses of tumour immune microenvironment between collecting duct carcinoma and fumarate hydratase-deficient renal cell carcinoma
AID  - 10.1136/jcp-2022-208589
DP  - 2022 Nov 08
TA  - Journal of Clinical Pathology
PG  - jcp-2022-208589
4099  - http://jcp.bmj.com/content/early/2022/11/08/jcp-2022-208589.short
4100  - http://jcp.bmj.com/content/early/2022/11/08/jcp-2022-208589.full
AB  - Aims Collecting duct carcinoma (CDC) and fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) have similar histological morphologies and both show a poor prognosis. Programmed death ligand 1 (PD-L1) inhibitor has been approved for the treatment of RCC. However, tumour-infiltrating neutrophils stimulated by interleukin-8 (IL-8) interfere with PD-L1 inhibitors. Here, we retrospectively analysed PD-L1 and IL-8 expression, and examined its relationship with infiltrating immune cells.Methods Nine cases of CDC and seven cases of FH-deficient RCC were selected. We defined PD-L1 and IL-8 expression by the Tumour Proportion Score and Combined Positive Score (CPS). We counted the numbers of CD8+, CXCR2+, CD11b+, CD66b+ and CD33+ immune cells located in the tumour components.Results A number of CXCR2+ (p=0.0058), CD11b+ (p=0.0070) and CD66b+ (p=0.0067) immune cells infiltrating into CDC were significantly higher than those infiltrating into FH-deficient RCC. In CDC, PD-L1 expression was correlated with a high density of CD8+ lymphocytes (p=0.0389), but was not in FH-deficient RCC (p=0.6985). IL-8 CPS was significantly higher in CDC than in FH-deficient RCC (p=0.0069). In addition, among the CDC cases, IL-8 CPS showed significant positive correlations with CXCR2+, CD11b+ and CD66b+ immune cell densities (p=0.0250, p=0.0104 and p=0.0374, respectively), whereas FH-deficient RCC showed no significant correlations between IL-8 CPS and immune cell densities.Conclusions Our results suggest the difference of each tumour microenvironment between CDC and FH-deficient RCC, and IL-8 is a potential therapeutic target for treating CDC, but not FH-deficient RCC.No data are available.