METHODS: A detailed assessment of immune cell populations was performed using a total of 1,700 microscopic images from ccRCCs from 11 patients, their corresponding pancreatic metastases and ccRCCs from 10 patients without pancreatic metastases. Tumor specimens were stained for CD45, CD8, CD163 and FOXP3 and the densities of the respective immune cells were assessed semiquantitatively in the intratumoral and extratumoral compartment. Multispectral imaging was performed in selected tumors.
RESULTS: We found that pancreatic metastases show the lowest intratumoral infiltration with CD8+ cytotoxic T lymphocytes of all tumor specimens analyzed. The frequency of CD8+ lymphocytes was on 1.9 fold lower in pancreatic metastases (median density 8.3 cells per field of view [FOV] = 1.23 mm2) when compared to the corresponding primary tumor (15.6 cells per FOV, P = 0.0002) and more than 3-fold lower when compared to ccRCCs without pancreatic metastases (27.2 cells per FOV, P = 0.0012). There was also a significantly reduced intratumoral infiltration with immunosuppressive FOXP3+ lymphocytes in pancreatic metastases (2.6 cells per FOV, P = 0.009) and corresponding primary tumors (2 cells per FOV, P = 0.028) when compared to ccRCCs without pancreatic metastases (5.6 cells per FOV).
CONCLUSIONS: In this proof-of-concept study, we show that pancreatic metastases of ccRCC present with unique immunological features including a low intratumoral density of CD8+ and FOXP3+ lymphocytes. The low counts of CD8+ and FOXP3+ lymphocytes may reflect less aggressive features of ccRCC with pancreatic metastasis that may result in a more favorable patient prognosis.
方法:使用来自11名患者的1,700张ccRCC的显微镜图像对免疫细胞群进行了详细评估,10例无胰腺转移患者的相应胰腺转移和ccRCC。对肿瘤标本进行CD45,CD8,CD163和FOXP3染色,并半定量评估肿瘤内和瘤外隔室中各自免疫细胞的密度。在选定的肿瘤中进行多光谱成像。
结果:我们发现,在所有分析的肿瘤标本中,胰腺转移显示出最低的CD8细胞毒性T淋巴细胞瘤内浸润。与相应的原发性肿瘤相比,胰腺转移灶中CD8淋巴细胞的频率低1.9倍(每个视野[FOV]=1.23mm2的中位密度8.3个细胞)(每个FOV15.6个细胞,P=0.0002),与无胰腺转移的ccRCC相比,低3倍以上(每FOV27.2个细胞,P=0.0012)。胰腺转移瘤中免疫抑制FOXP3+淋巴细胞的瘤内浸润也显着减少(每FOV2.6个细胞,P=0.009)和相应的原发性肿瘤(每个FOV2个细胞,当与没有胰腺转移的ccRCC(5.6个细胞/FOV)相比时,P=0.028)。
结论:在这项概念验证研究中,我们显示ccRCC的胰腺转移具有独特的免疫学特征,包括CD8和FOXP3淋巴细胞的低肿瘤内密度。CD8+和FOXP3+淋巴细胞的低计数可能反映了ccRCC伴胰腺转移的侵袭性较小的特征,这可能导致更有利的患者预后。