Al Nabhani Safia, Al Harthy Athra, Al Riyami Marwa, Al Sinawi Shadia, Al Rashdi Afrah, Al Husseni Samiya, Kumar Shiyam
Histopathology Residency Training Program, Oman Medical Specialty Board, Muscat, Oman.
Department of Pathology, Sultan Qaboos University Hospital, Muscat, Oman.
Oman Med J. 2022 Nov 30;37(6):e441. doi: 10.5001/omj.2022.96. eCollection 2022 Nov.
To evaluate the expression of programmed death-ligand 1 (PD-L1) in bladder cancer cases in Oman using immunohistochemistry, and to determine whether the level of PD-L1 expression is associated with tumor grade, stage, or outcome. An additional objective was to identify the clinicopathological features of bladder cancer among Omanis.
This was a retrospective cohort study of patients where we subjected archived tissue samples to prospective analysis. All patients diagnosed and treated for bladder cancer in Sultan Qaboos University Hospital from January 2006 to December 2017 and followed up for at least one year were included. Clinical and demographical information of the patients was obtained from their medical records. PD-L1 testing using immunohistochemistry was performed on formalin-fixed paraffin-embedded tissue blocks. Scoring of PD-L1 expression by tumor cells was conducted independently by two pathologists. Positivity was defined using two different cut-off values (≥ 5% and ≥ 25%) of tumor cells showing membrane or cytoplasmic staining. The outcome was divided into two categories either no recurrence at the last follow-up, or recurrence/disease progression/death.
There were 68 cases of bladder cancer; 72.1% were male; the age range was 35-89 years (mean = 65.3 and median = 66). The largest number of patients were diagnosed with stage II cancer (38.8%) followed by stage I cancer (32.8%). Hematuria was the most common presentation (58.7%). High-grade tumors were seen in 83.8% (57/68) of patients. Invasive urothelial carcinoma appeared in 79.4% (54/68). PD-L1 tests were performed on 63 cases where tissue blocks were available. PD-L1 was positive in 44.4% of cases using a cut-off value of 5%; however, it dropped to 30.2% at a cut-off value of 25%. At the cut-off value of 5%, PD-L1 was significantly associated with tumor grade ( 0.033), but the significance was lost when the cut-off value of 25% was applied ( 0.250). No significant association was found between PD-L1 expression and outcome using both cut-off values and stage at diagnosis ( 0.798 and 0.102, respectively).
This study showed that at a cut-off value of ≥ 5%, 44.4% of cases of bladder cancer were PD-L1 positive. There was a significant association between PD-L1 expression in bladder cancer and tumor grade. No statistically significant association was found between tumor stage and outcome. The results indicated the potential benefit of anti-PD-L1 immunotherapy for patients with high tumor grades.
采用免疫组织化学方法评估阿曼膀胱癌病例中程序性死亡配体1（PD-L1）的表达情况，并确定PD-L1表达水平是否与肿瘤分级、分期或预后相关。另一个目的是确定阿曼人膀胱癌的临床病理特征。
这是一项对患者的回顾性队列研究，我们对存档的组织样本进行前瞻性分析。纳入2006年1月至2017年12月在苏丹卡布斯大学医院诊断和治疗且随访至少一年的所有膀胱癌患者。患者的临床和人口统计学信息从其病历中获取。对福尔马林固定石蜡包埋的组织块进行免疫组织化学PD-L1检测。由两名病理学家独立对肿瘤细胞的PD-L1表达进行评分。使用肿瘤细胞显示膜或细胞质染色的两种不同临界值（≥5%和≥25%）定义阳性。结局分为两类，即最后一次随访时无复发，或复发/疾病进展/死亡。
共有68例膀胱癌病例；72.1%为男性；年龄范围为35 - 89岁（平均 = 65.3岁，中位数 = 66岁）。诊断为II期癌症的患者数量最多（38.8%），其次是I期癌症（32.8%）。血尿是最常见的表现（58.7%）。83.8%（57/68）的患者为高级别肿瘤。浸润性尿路上皮癌占79.4%（54/68）。对63例有组织块的病例进行了PD-L1检测。以5%为临界值时，44.4%的病例PD-L1呈阳性；然而，以25%为临界值时，该比例降至30.2%。以5%为临界值时，PD-L1与肿瘤分级显著相关（P = 0.033），但应用25%的临界值时这种相关性消失（P = 0.250）。使用两种临界值以及诊断时的分期，均未发现PD-L1表达与结局之间存在显著关联（分别为P = 0.798和P = 0.102）。
本研究表明，以≥5%为临界值时，44.4%的膀胱癌病例PD-L1呈阳性。膀胱癌中PD-L1表达与肿瘤分级之间存在显著关联。未发现肿瘤分期与结局之间存在统计学显著关联。结果表明抗PD-L1免疫疗法对高肿瘤分级患者可能有益。
