Prognostic Significance of B7-H3, TROP2, and p16 Expression in Pleural Mesothelioma: Clinicopathological Correlations and Survival Outcomes

Our plain-English summary of Prognostic Significance of B7-H3, TROP2, and p16 Expression in Pleural Mesothelioma: Clinicopathological Correlations and Survival Outcomes, by N. Tas, R.O. Yüceer, T. Koc, et al (Journal of Clinical Medicine, 2026).

The study

• Authors: N. Tas, R.O. Yüceer, T. Koc, Y. Sönmez, H. Dogan
• Journal: Journal of Clinical Medicine
• Published: 2026;15(20)
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Pleural mesothelioma (PM) is an aggressive malignancy with considerable biological heterogeneity and few established prognostic biomarkers. We evaluated the clinicopathological and prognostic relevance of B7-H3, TROP2, and p16 expression in PM. Methods: This retrospective study included 50 patients with histologically confirmed PM diagnosed between 2016 and 2025. Immunohistochemical expression of B7-H3, TROP2, and p16 was evaluated using an immunoreactivity scoring system. Associations with clinicopathological features were examined, and overall survival (OS) and progression-free survival (PFS) were analyzed using Kaplan-Meier and Cox proportional hazards methods. Results: High B7-H3, TROP2, and p16 expression was observed in 78%, 18%, and 20% of tumors, respectively. High B7-H3 expression was significantly associated with asbestos exposure, chemotherapy, and tumor stage. Patients with high B7-H3 expression had shorter median OS (11.0 vs. 42.0 months; p < 0.001) and PFS (11.0 vs. 40.0 months; p = 0.004) than those with negative/low expression. Neither TROP2 nor p16 expression was significantly associated with survival. In a parsimonious multivariable Cox model, high B7-H3 expression remained significantly associated with poorer OS after adjustment for disease stage (HR = 4.42, 95% CI: 1.29-15.21, p = 0.018). Conclusions: B7-H3 is frequently expressed in PM and was associated with poorer survival, including after adjustment for disease stage. These findings support further investigation of B7-H3 as a potential prognostic biomarker and therapeutic target in PM.

In plain English

This retrospective single-center study in Turkey examined tumor tissue from 50 patients with pleural mesothelioma diagnosed between 2016 and 2025. The authors measured three proteins (B7-H3, TROP2 and p16) by tissue staining and compared them with patient features and survival. Records showed a history of asbestos exposure in 34 patients (68.0%); fiber types and amounts were not described. High B7-H3 was found in 39 patients (78.0%). These patients more often had a history of asbestos exposure than those with low or negative B7-H3 (76.9% vs. 36.4%). Asbestos exposure itself was not significantly associated with survival. Median overall survival was 11.0 months (95% CI 7.3 to 14.7) with high B7-H3 versus 42.0 months (95% CI 30.2 to 53.8) with low or negative B7-H3. Adjusted for stage, high B7-H3 had a hazard ratio for death of 4.42 (95% CI 1.29 to 15.21). B7-H3 was not independently associated with progression-free survival in the fully adjusted model. TROP2 and p16 were not significantly associated with survival. The authors concluded that B7-H3 showed the strongest prognostic association of the three markers and called for larger, independent studies.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective observational cohort study (single center) of tumor tissue staining (immunohistochemistry) and survival
• Who was studied: 50 patients with pleural mesothelioma diagnosed between 1 January 2016 and 1 January 2025 at Sivas Cumhuriyet University, Turkey. Of 72 consecutive patients, 22 were excluded. Mean age was 66.7 years; 31 were men and 19 were women. 42 (84.0%) had the epithelioid subtype.
• Exposure: The main factors studied were tumor expression of B7-H3, TROP2 and p16, scored as negative/low (IRS 0 to 4) or high (IRS above 4). A history of asbestos exposure was taken from records and was present in 34 patients (68.0%). No fiber types, sources or doses are given.
• Main results:
  • High expression was found for B7-H3 in 39 of 50 patients (78.0%), for TROP2 in 9 patients (18.0%) and for p16 in 10 patients (20.0%).
  • A history of asbestos exposure was more frequent in the high B7-H3 group than in the low/negative B7-H3 group (76.9% vs. 36.4%, p = 0.016). TROP2 and p16 expression were not significantly associated with asbestos exposure (p = 0.605 and p = 0.400).
  • In the univariable survival analysis, asbestos exposure was not significantly associated with overall survival (HR 1.483, 95% CI 0.741 to 2.970, p = 0.266).
  • Stage I to II disease was more frequent in the high B7-H3 group (79.5%). Stage III to IV disease predominated in the low/negative B7-H3 group (81.8%), p less than 0.001.
  • Median overall survival was 42.0 months (95% CI 30.2 to 53.8) for low/negative B7-H3 versus 11.0 months (95% CI 7.3 to 14.7) for high B7-H3, p less than 0.001.
  • Median progression-free survival was 40.0 months (95% CI 4.7 to 75.3) for low/negative B7-H3 versus 11.0 months (95% CI 7.9 to 14.1) for high B7-H3, p = 0.004.
  • TROP2 was not associated with overall survival (median 15.0 months low/negative vs. 13.0 months high, p = 0.585). p16 was not significantly associated with overall survival (13.0 vs. 20.0 months, p = 0.233).
  • Fully adjusted model (Model 3) for overall survival: high B7-H3 HR 7.81 (95% CI 1.68 to 36.36, p = 0.009). In a smaller model adjusting only for stage, high B7-H3 HR was 4.42 (95% CI 1.29 to 15.21, p = 0.018).
  • For progression-free survival in the fully adjusted model, only advanced stage was independently associated (HR 25.18, 95% CI 4.58 to 138.35). B7-H3 was not (HR 1.35, 95% CI 0.35 to 5.26, p = 0.666).
• The authors' conclusion: The authors concluded that B7-H3 showed the strongest prognostic association of the three markers and was associated with poorer overall survival, while TROP2 and p16 were not independently associated with survival. They said larger, independent studies are needed to validate the findings.
• Limitations the authors state:
  • The retrospective, single-center design and small cohort may limit how widely the results apply.
  • The biomarker cutoffs were taken from previous literature and need validation in independent cohorts.
  • No molecular data on CDKN2A status were available, and the link between biomarker expression and treatment response could not be fully assessed.
  • Few tumors had low B7-H3 expression, so the finding that high B7-H3 was more common in early-stage tumors should be interpreted cautiously.
  • Only nine patients had high TROP2 expression, which limited the analysis of TROP2 and survival.
  • Response to B7-H3-targeted treatment was not evaluated, so the study does not establish B7-H3 as a predictor of treatment response.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Biomarker, Overall Survival, Progression-Free Survival, Asbestos Exposure, Chemotherapy.

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