Departments of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, NC.
AU/UGA Medical Partnership, Medical College of Georgia, Athens, GA; and.
Am J Dermatopathol. 2021 Jan 1;43(1):21-26. doi: 10.1097/DAD.0000000000001622.
The PD-1/PD-L1 pathway plays a critical role in the physiologic inhibition and modulation of the immune response in normal tissue. Many tumors evade immune detection and response by upregulating PD-L1 expression. Humanized monoclonal PD-1 and PD-L1 antibodies have proven as both tolerable and effective treatment in many neoplasms. Extramammary Paget disease (EMPD) is a deformative and debilitating cutaneous malignancy in which definitive treatment options are limited with high recurrence rates after surgical excision. To the best of our knowledge, there is little published information regarding EMPD and PD-L1 expression. We evaluated 18 EMPD surgical pathology cases for tumor cell and tumor-associated inflammatory (TAI) cell PD-L1 expression. We identified PD-L1 tumor cell expression in 3 (17%) of the cases: 2 of 4 invasive cases (50%) and 1 of 14 (7%) noninvasive cases. One invasive case had lymph nodal metastasis with PD-L1 tumor cell expression. The host inflammatory response intensity and PD-L1 expression were variable in cases negative for tumor cell PD-L1 expression; however, a marked inflammatory response and TAI PD-L1 expression were present in all cases positive for tumor cell PD-L1 expression. In conclusion, 1 in 14 (7%) in situ EMPD cases showed tumor cell PD-L1 expression and 2 of 4 invasive cases (50%) showed tumor cell PD-L1 expression. TAI cells were more often positive (83%) than tumor cells (17%) for PD-L1 expression.
PD-1/PD-L1 通路在正常组织的免疫反应抑制和调节中起着关键作用。许多肿瘤通过上调 PD-L1 表达来逃避免疫检测和反应。人源化单克隆 PD-1 和 PD-L1 抗体已被证明在许多肿瘤中具有耐受性和有效性。乳腺外 Paget 病（EMPD）是一种变形性和使人虚弱的皮肤恶性肿瘤，其明确的治疗选择有限，手术切除后复发率高。据我们所知，关于 EMPD 和 PD-L1 表达的信息很少。我们评估了 18 例 EMPD 手术病理病例的肿瘤细胞和肿瘤相关炎症（TAI）细胞 PD-L1 表达。我们发现 3 例（17%）肿瘤细胞表达 PD-L1：4 例侵袭性病例中有 2 例（50%），14 例非侵袭性病例中有 1 例（7%）。1 例侵袭性病例有淋巴结转移且肿瘤细胞表达 PD-L1。在肿瘤细胞 PD-L1 表达阴性的病例中，宿主炎症反应强度和 PD-L1 表达是可变的；然而，所有肿瘤细胞 PD-L1 表达阳性的病例均存在明显的炎症反应和 TAI PD-L1 表达。总之，原位 EMPD 病例中有 1 例（7%）显示肿瘤细胞 PD-L1 表达，4 例侵袭性病例中有 2 例（50%）显示肿瘤细胞 PD-L1 表达。TAI 细胞比肿瘤细胞（17%）更常表达 PD-L1（83%）。
