en Cancer Cancer Original Article Original Article <p style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Tahoma;"><span style="line-height:14.0pt">Ectopic expression of Placenta-specific 1 (PLAC1), a Cancer/Testis Antigen (CTA), was reported in various tumors, but its clinical relevance and prognostic value in bladder urothelial carcinoma (UC) remain unclear. This study evaluated PLAC1 expression in the membrane, cytoplasm, and nucleus of tumor cells and its clinicopathological significance in bladder UC patients. We analyzed 177 bladder UC samples to assess nuclear, cytoplasmic, and membranous PLAC1 expression by immunohistochemistry (IHC) on tissue microarrays (TMAs) and examined its associations with clinicopathological characteristics and prognosis. Higher cytoplasmic expression of PLAC1 was associated with increased histological grade (<i>P<b><</b><b><i> </i></b>0.001</i>), advanced pathological primary tumor (pT) staging (<i>P=<i> </i>0.038</i>), lamina propria involvement (<i>P=<i> </i>0.013</i>), and lamina propria/muscularis (L/M) involvement (<i>P=<i> </i>0.038</i>). A significant association was identified between the increased nuclear expression of PLAC1 and tumor size (<i>P= 0.036</i>) and higher histological grades (intensity of staining, <i>P=<i> </i>0.045</i>). PLAC1 expression was not significantly associated with disease-specific survival (DSS) or progression-free survival (PFS) in bladder UC patients.</span></span></span><br> <span style="font-size:11pt"><span style="line-height:14.0pt"><span style="text-autospace:none"><span style="font-family:Calibri,sans-serif"><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-size:12px;"><span style="font-family:Tahoma;">Cytoplasmic PLAC1 expression significantly correlates with higher tumor grade and advanced stage in bladder cancer, suggesting its potential as an exploratory biomarker. The association between PLAC1 expression and tumor invasiveness warrants further functional and prospective studies to clarify its biological</span></span> significance.</span></span></span></span></span></span></p> PLAC1 (Placenta-specific1), Bladder urothelial carcinoma (UC), Immunohistochemistry, Tissue microarray (TMA), Histological grade, pT Stage, Bladder cancer 1434 1448 http://ijmcmed.org/browse.php?a_code=A-10-9122-1&slc_lang=en&sid=1 Shima Dorafshan shima.dorafshan@gmail.com 100319475328460038302 0009-0000-7252-7002 No Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran Zahra Madjd zahra.madjd@yahoo.com 100319475328460038303 100319475328460038303 No Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran Leili Saeednejad Zanjani saeednejadleily@yahoo.com 100319475328460038304 100319475328460038304 No Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran Mandana Rahimi mandanarh@yahoo.com 100319475328460038305 100319475328460038305 No Hasheminejad Kidney Center, Pathology Department, Iran University of Medical Sciences (IUMS), Tehran, Iran Sadegh Safaei safaei63@gmail.com 100319475328460038306 100319475328460038306 No Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran Nasrin Borumandnia borumand.n@gmail.com 100319475328460038307 100319475328460038307 No Department of Epidemiology and Biostatistics, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran Amir-Hassan Zarnani zarnania@gmail.com 100319475328460038308 100319475328460038308 No Department of Immunology, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran. roya Ghods rghods77@yahoo.com 100319475328460038301 100319475328460038301 Yes Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran