Rovalpituzumab tesirine (Rova-T), an antibody-drug conjugate directed against Delta-like protein 3 (DLL3), is under development for patients with small cell lung cancer (SCLC). DLL3 is expressed on the majority of SCLC samples. Because SCLC is rarely biopsied in the course of disease, data regarding DLL3 expression in relapses is not available. The aim of this study was to investigate the expression of DLL3 in chemorelapsed (but untreated with Rova-T) SCLC samples and compare the results with chemonaive counterparts. Two evaluation methods to assess DLL3 expression were explored. Additionally, we assessed if DLL3 expression of chemorelapsed and/or chemonaive samples has prognostic impact and if it correlates with other clinicopathological data. The study included 30 paired SCLC samples, which were stained with an anti DLL3 antibody. DLL3 expression was assessed using tumor proportion score (TPS) and H-score and was categorized as DLL3 low (TPS < 50%, H-score ≤ 150) and DLL3 high (TPS ≥ 50%, H-score > 150). Expression data were correlated with clinicopathological characteristics. Kaplan–Meier curves were used to illustrate overall survival (OS) depending on DLL3 expression in chemonaive and chemorelapsed samples, respectively, and depending on dynamics of expression during course of therapy. DLL3 was expressed in 86.6% chemonaive and 80% chemorelapsed SCLC samples without significant differences between the two groups. However, the extent of expression varied in a substantial proportion of pairs (36.6% with TPS, 43.3% with H-score), defined as a shift from low to high or high to low expression. TPS and H-score provided comparable results. There were no profound correlations with clinicopathological data. Survival analysis revealed a trend toward a more favorable OS in DLL low-expressing chemonaive SCLC (p = 0.57) and, in turn, in DLL3 high-expressing chemorelapsed SCLC (p = 0.42) as well as in SCLC demonstrating a shift from low to high expression (p = 0.56) without being statistically significant. This is the first study to investigate DLL3 expression in a large cohort of rare paired chemonaive-chemorelapsed SCLC specimens. Comparative analysis revealed that DLL3 expression was not stable during the course of therapy, suggesting therapy-based alterations. Unlike in chemonaive samples, a high DLL3 expression in chemorelapsed samples indicated a trend for a more favorable prognosis. Our results highlight the importance to investigate DLL3 in latest chemorelapsed SCLC tumor tissue.

Background: Lung cancer is the most frequent cause of cancer-related deaths worldwide. The clinical development of immune checkpoint blockade has dramatically changed the treatment paradigm for patients with lung cancer. Yet, an improved understanding of PD-1/PD-L1 checkpoint blockade-responsive biology is warranted. Methods: We aimed to identify the landscape of immune cell infiltration in primary lung adenocarcinoma (LUAD) in the context of tumoral PD-L1 expression and the extent of immune infiltration (“hot” vs. “cold” phenotype). The study comprises LUAD cases (n = 138) with “hot” (≥150 lymphocytes/HPF) and “cold” (50%) and negative (<1%) tumor PD-L1 expression, respectively. Tumor samples were immunohistochemically analyzed for expression of PD-L1, CD4, and CD8, and further investigated by transcriptome analysis. Results: Gene set enrichment analysis defined complement, IL-JAK-STAT signaling, KRAS signaling, inflammatory response, TNF-alpha signaling, interferon-gamma response, interferon-alpha response, and allograft rejection as significantly upregulated pathways in the PD-L1-positive hot subgroup. Additionally, we demonstrated that STAT1 is upregulated in the PD-L1-positive hot subgroup and KIT in the PD-L1-negative hot subgroup. Conclusion: The presented study illustrates novel aspects of PD-L1 regulation, with potential biological relevance, as well as relevance for immunotherapy response stratification.

Background/Objectives: Perineural (PnI), lymphatic (LI), and vascular invasion (VI) in tumor specimens are supposed to worsen the clinical course of oral squamous cell carcinoma (OSCC) and negatively influence survival outcomes. Despite this, these histologic features have not been implemented in the international staging recommendation for OSCC and their prognostic role remains questionable due to inconsistent findings in the related literature. Methods: To investigate the impact of PnI, LI, and VI on oral cancer-specific (OCSS), recurrence-free (RFS), and overall survival (OS), we hypothesized that these histologic features are independent risk factors for poor survival and therefore considered within a prospectively maintained single-center cohort of patients with OSCC. LI and VI were assessed together and reported as lymphovascular invasion (LVI). Results: This study included 439 patients with primary OSCC. Sixty-nine Patients (21.9%) had at least one of the two risk factors. Within the 5-year follow-up period, 61 of these patients (64%) died, and 30 patients (31%) developed locoregional recurrences. Both perineural and lymphovascular invasion were strongly correlated with the presence of lymph node metastasis. PnI and LVI were investigated separately using an adjusted Cox’s proportional hazards regression model. In addition to higher tumor size and the presence of nodal disease (higher stage) the presence of LVI was associated with poor OS, OCSS, and RFS on multivariate analysis, while PnI was associated with reduced OS. In stage III/IV postoperative radiotherapy improved survival in patients with PnI but not with LVI. Conclusions: We conclude that the evidence of LVI in tumor specimens should be considered a high-risk factor when planning adjuvant treatment and monitoring patients with OSCC.

Aim: Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related death globally despite promising progress of personalized therapy approaches. Cyclin-dependent kinase 7 (CDK7) is a kinase involved in transcription, overexpressed in a broad spectrum of cancer types and found to be associated with an unfavourable prognosis. In this study, we aimed to investigate the protein expression of CDK7 in a large cohort of NSCLC incorporating adenocarcinomas (adNSCLC) and squamous cell carcinomas (sqNSCLC) and to correlate its expression with clinicopathological data.Methods: We performed immunohistochemical staining of CDK7 on our cohort of NSCLC including 258 adNSCLC and 101 sqNSCLC and measured protein expression via a semi-automated read out. According to the median value of CDK7 the cohort was stratified in a CDK7 high and low expressing group, respectively, and results were correlated with clinico-pathological data.Results: CDK7 was significantly higher expressed in sqNSCLC than in adNSCLC. In the group of sqNSCLC, CDK7 expression was significantly higher in sqNSCLC with lymph node metastases than in sqNSCLC with N0 stage. We found a significantly worse overall survival and disease-free survival for patients with CDK7 high expressing NSCLC.Conclusion: Since a high CDK7 expression seems to be linked with a poor prognosis it might serve as a promising novel prognostic biomarker and its assessment could be implied in future routine diagnostic workup of NSCLC samples. Considering that CDK7 inhibitors are currently tested in several trials for advanced solid malignancies, it may also be a new target for future anti-cancer therapy.

Background: Recurrent oral squamous cell carcinoma (re-OSCC) poses a serious therapeutic challenge and is linked to poor survival outcomes. SOX2 and NANOG, key transcription factors in cancer stem cell biology, may drive tumor progression and therapy resistance. However, their prognostic value in re-OSCC and their relationship to adjuvant therapy remain unclear. Methods: We retrospectively analyzed a single-center cohort of 94 patients with re-OSCC treated with curative intent via (1) surgery alone, (2) surgery plus adjuvant radiotherapy (RT), or (3) surgery plus adjuvant radiochemotherapy (RCT). Tissue microarrays (TMAs) were constructed from matched primary and recurrent tumors and immunohistochemical (IHC) staining for SOX2, and NANOG was quantified using H-scores. Post-recurrence overall survival (prOS) and post-recurrence disease-free survival (prDFS) were evaluated using Kaplan–Meier analysis and Cox proportional hazards models. Results: SOX2 expression and survival: Elevated SOX2 expression (H-score > 14) in re-OSCC was significantly associated with improved prOS (p = 0.013) and prDFS (p = 0.026). Notably, patients who had received adjuvant therapy (particularly RCT) showed higher SOX2 levels in recurrent tumors compared to those treated with surgery alone. NANOG expression and therapy: NANOG expression declined markedly from primary to recurrent tumors (median H-score 42.2 vs. 8.7; p < 0.001). This decline was most pronounced in patients treated with surgery alone. Despite this dynamic change, NANOG expression did not correlate significantly with prOS or prDFS. Other prognostic factors include advanced tumor stage (rT2–rT4) and lymph node involvement (rN+/x)m which remained significant predictors of worse survival in the recurrent setting, regardless of adjuvant therapy. Conclusion: SOX2 overexpression in re-OSCC correlates with better survival, suggesting a unique prognostic role distinct from primary disease. Adjuvant therapy, especially RCT, appears to maintain or elevate SOX2 levels, potentially contributing to improved treatment response. In contrast, although NANOG expression decreases in recurrence, particularly in patients who undergo surgery alone, it does not significantly affect survival outcomes. These findings underscore the importance of context-specific biomarker assessments and provide a rationale for incorporating SOX2 status into personalized treatment strategies for re-OSCC.