Prostate cancer remains a significant global health concern, with approximately 1.6 million new cases and 366,000 deaths annually. The average age at diagnosis is 66 years [4, 13, 14]. While PCa typically progresses slowly and is often asymptomatic in its early stages, its detection heavily relies on histopathological biopsy as the gold standard [15, 16]. Current diagnostic practices emphasize basal compartment markers CK34βE12 and P63, complemented by AMACR for malignant confirmation. However, CK34βE12’s notorious sensitivity to formalin fixation leads to inconsistent staining or false-negative results in up to 25% of cases [17, 18], whereas P63’s aberrant expression in rare adenocarcinoma subtypes or HGPIN introduces interpretative complexity [13, 14]. These limitations underscore the critical need for novel complementary markers with enhanced robustness.

GATA3: A Nuclear Beacon for Basal Cell Identification. It’s a nuclear transcription factor with unparalleled specificity, emerged as a compelling candidate. In our cohort, GATA3 demonstrated nuclear expression in 92.21% of BPH basal cells, matching the sensitivity of P63 (92.21%) and CK34βE12 (93.51%). Notably, its complete absence in PCa basal cells (κ = 1 vs. P63 and CK34βE12) highlights exceptional diagnostic robustness. Unlike CK34βE12’s cytoplasmic artifacts caused by fixation variability [17], GATA3’s crisp nuclear localization (Fig. 2A) provides superior morphological delineation, reducing interobserver discordance-a critical advantage aligned with Shah et al.‘s emphasis on nuclear markers for minimizing diagnostic ambiguity [16]. Mechanistically, while GATA3’s role in mammary/urothelial differentiation is established [16], its conserved regulatory function in prostate basal cells warrants deeper exploration, potentially through lineage-tracing models.

CD138,redefining Its role beyond tumor progression.CD138(syndecan-1), traditionally associated with tumor invasion and poor prognosis in malignancies like multiple myeloma [21, 22], exhibited unexpected specificity in prostate basal cells. In BPH, CD138 showed cytoplasmic expression in 96.10% of cases, closely aligning with CK34βE12 (κ = 0.737). Its complete negativity in PCa (specificity = 92.59% vs. P63) contrasts with prior studies linking CD138 to cancer aggressiveness [23], suggesting tissue-specific roles. This paradox may arise from epigenetic silencing during malignant transformation, as proposed by Kind et al. [24]. Our findings partially align with Böttcher et al.‘s multiplex IHC study [25], which detected CD138 in 78% of benign basal cells versus 4% of malignant glands. However, their orthogonal tissue validation confirmed occasional CD138 expression in luminal epithelial metaplasia-a phenomenon not observed in our cohort due to strict morphologic exclusion criteria.Clinically, CD138’s strong cytoplasmic staining could serve as a reliable adjunct to CK34βE12, particularly in small biopsies where fixation artifacts impair CK34βE12 reliability. The integration of GATA3 and CD138 could mitigate CK34βE12’s limitations, especially in resource-limited settings where standardized fixation protocols are challenging to implement. This study demonstrates that CD138 and GATA3 exhibit similar efficacy to P63 and CK34βE12 in identifying prostate basal cells, based on positive expression rates, sensitivity, and specificity analyses. In equivocal cases (e.g., ASAP or HGPIN), dual staining with GATA3 (nuclear) and CD138 (cytoplasmic) could resolve ambiguities caused by P63’s aberrant expression [13].GATA3’s fixation-resistant nuclear staining may lower false-negative rates in small biopsies, where CK34βE12 frequently underperforms [17].Therefore, GATA3 and CD138 show sufficient basal compartment affinity to serve as adjunctive markers in prostate diagnostics, particularly when conventional markers yield equivocal results. Further research is needed to elucidate the molecular mechanisms underlying the specific expression of GATA3 and CD138 in prostate basal cells. Although CD138 has been implicated in luminal epithelial regulation [25], our rigorous morphological analysis confirmed its exclusive basal localization. This finding aligns with Kind et al.‘s hypothesis of syndecan-1 polarity inversion in premalignant lesions [24].

While our data strongly support the diagnostic utility of GATA3 and CD138 in prostate basal compartment evaluation (Fig. 4) the observed predominant basal localization in BPH should not be conflated with cell-type specificity. CD138 exhibits variable expression in plasma cell infiltrates and secretory epithelium under inflammatory conditions [24], while GATA3 shows consistent expression in bladder urothelial carcinomas [26]. These patterns necessitate contextual interpretation guided by morphologic correlation-for instance, avoiding CD138 reliance in prostatic specimens with extensive chronic inflammation (as per our exclusion criteria).

Fig. 4

Cohen’s Kappa agreement analysis between markers in BPH and PCa. BPH cohor: Paired marker agreement represented by filled circles (GATA3-p63: κ = 1.00; GATA3-CK34βE12: κ = 0.902; CD138-p63: κ = 0.648; CD138-CK34βE12: κ = 0.737). Confidence intervals (95% CI) derived from Monte Carlo bootstrap (10,000 iterations). PCa cohort: Perfect agreement (κ = 1.0) among all markers. Horizontal bars represent 95% CI. Statistical significance determined by McNemar-Bowker test (***p < 0.001). Inter-group comparisons analyzed by Fisher’s exact test

Methodological constraints:

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Technical: Lack of laser capture microdissection may compromise molecular specificity.

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Population: Subtype analysis limited by ductal adenocarcinoma underrepresentation.

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Mechanistic: RNAscope validation needed for GATA3 transcriptional regulation mapping.

Proposed multi-center initiatives:

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Establish pre-analytical standardization protocols for fixation-sensitive markers.

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Conduct phased biomarker validation per REMARK guidelines.

3.

Develop AI-assisted quantification algorithms for multi-marker panels.