内容紹介
Summary
The purpose of this study was to evaluate the prognostic significance of programmed cell death-ligand 1(PD-L1)expression and CD8+T cells in the immune microenvironment. From January 2011 to December 2011, we retrospectively examined 31 patients with Stage Ⅲ colorectal cancer. PD-L1 expression and CD8+T cell counts were evaluated by immunohistochemical study using whole-tumor slides. PD-L1 expression in cancer cells(PDCC)and in tumor-infiltrating stromal cells(PDSC)was divided into high(H)and low(L)groups. CD8+T cells were counted in the core of the tumor(CDCT)and in the invasive margin of the tumor area(CDIM), and divided into high(H)and low(L)groups. Based on a median follow-up time of 69.3 months, the 5-year overall survival and disease-free survival of all patients were 74.2% and 64.5%, respectively. The overall survival was significantly longer for patients in the CDIM-H group(82.6%)than those in the CDIM-L group(50.0%; p=0.034). Patients in the PDSC-H group also tended to have superior overall survival than those in the PDSC-L group(84.2% and 58.3%, respectively, p=0.094). In conclusion, both CD8+T cells and tumor-infiltrating immune cells with PD-L1 may indicate antitumoral function in patients with Stage Ⅲ colorectal cancer.
要旨
Stage Ⅲ大腸癌におけるPD-L1発現とそれに関連する腫瘍局所のCD8+Tリンパ球数の定量を行い予後との関係について検討した。2011年1～12月の間に根治切除術が行われたStage Ⅲ大腸癌31例について腫瘍最大割面を通るホルマリン固定標本を用いてPD-L1染色,CD8染色を行った。PD-L1については腫瘍細胞(PDCC)と腫瘍間質に浸潤する免疫細胞(PDSC)での発現をそれぞれスコア化した。CD8+Tリンパ球数は腫瘍中心部(core of the tumor: CDCT)と腫瘍先進部(invasive margin: CDIM)において計測した。PD-L1発現とCD8+Tリンパ球数をそれぞれhigh(H)群,low(L)群に分類した。観察期間中央値は69.3か月で全症例の5年OS,DFSはそれぞれ74.2%,64.5%。CD8IM-H群(n=23)とCD8IM-L群(n=8)の5年OSは82.6%,50.0%で有意差あり(p=0.039)。PD-L1発現と予後については5年OSがPDSC-H群(n=19)とPDSC-L群(n=12)で84.2%,58.3%(p=0.094)。Stage Ⅲ大腸癌において腫瘍先進部に浸潤するCD8+Tリンパ球数は予後因子である可能性が示唆された。また,PDSC-H群は予後良好な傾向が認められた。
目次
The purpose of this study was to evaluate the prognostic significance of programmed cell death-ligand 1(PD-L1)expression and CD8+T cells in the immune microenvironment. From January 2011 to December 2011, we retrospectively examined 31 patients with Stage Ⅲ colorectal cancer. PD-L1 expression and CD8+T cell counts were evaluated by immunohistochemical study using whole-tumor slides. PD-L1 expression in cancer cells(PDCC)and in tumor-infiltrating stromal cells(PDSC)was divided into high(H)and low(L)groups. CD8+T cells were counted in the core of the tumor(CDCT)and in the invasive margin of the tumor area(CDIM), and divided into high(H)and low(L)groups. Based on a median follow-up time of 69.3 months, the 5-year overall survival and disease-free survival of all patients were 74.2% and 64.5%, respectively. The overall survival was significantly longer for patients in the CDIM-H group(82.6%)than those in the CDIM-L group(50.0%; p=0.034). Patients in the PDSC-H group also tended to have superior overall survival than those in the PDSC-L group(84.2% and 58.3%, respectively, p=0.094). In conclusion, both CD8+T cells and tumor-infiltrating immune cells with PD-L1 may indicate antitumoral function in patients with Stage Ⅲ colorectal cancer.
要旨
Stage Ⅲ大腸癌におけるPD-L1発現とそれに関連する腫瘍局所のCD8+Tリンパ球数の定量を行い予後との関係について検討した。2011年1～12月の間に根治切除術が行われたStage Ⅲ大腸癌31例について腫瘍最大割面を通るホルマリン固定標本を用いてPD-L1染色,CD8染色を行った。PD-L1については腫瘍細胞(PDCC)と腫瘍間質に浸潤する免疫細胞(PDSC)での発現をそれぞれスコア化した。CD8+Tリンパ球数は腫瘍中心部(core of the tumor: CDCT)と腫瘍先進部(invasive margin: CDIM)において計測した。PD-L1発現とCD8+Tリンパ球数をそれぞれhigh(H)群,low(L)群に分類した。観察期間中央値は69.3か月で全症例の5年OS,DFSはそれぞれ74.2%,64.5%。CD8IM-H群(n=23)とCD8IM-L群(n=8)の5年OSは82.6%,50.0%で有意差あり(p=0.039)。PD-L1発現と予後については5年OSがPDSC-H群(n=19)とPDSC-L群(n=12)で84.2%,58.3%(p=0.094)。Stage Ⅲ大腸癌において腫瘍先進部に浸潤するCD8+Tリンパ球数は予後因子である可能性が示唆された。また,PDSC-H群は予後良好な傾向が認められた。