Objective: Pancreatic cancer is the cancer type with the highest mortality rate worldwide, and despite advances in treatment, molecular biomarkers are needed for both early diagnosis for developing targeted therapies and improving survival rates in this challenging malignancy. In our study, the contributions of programmed death-ligand 1 (PD-L1) expression to the determination of pancreatic cancer subtypes and patient prognosis and its impact on survival were investigated. Material and Methods: Paraffin-embedded tissues from 92 patients diagnosed with pancreatic cancer were included in this study. Tumor-infiltrating lymphocytes (TILs) and lymphocytes in the stromal area within the tumor borders were scored as stromal TILs; lymphocytes in tumor islands were scored as intratumoral TILs. Staining in each area was scored as a percentage, and staining with a score of 5 or more in tumor and immune cells for PD-L1 was scored as positive. Results: After staining, a score of 5 or more with tPD-L1 staining was used to identify one patient as having micropapillary adenocarcinoma, three patients as having ductal adenocarcinoma, and four patients as having signet ring cell carcinoma. When the clinical parameters and outcomes were compared, a statistically significant difference was found between the histopathologic type of signet ring cell carcinoma and poor differentiation and positivity of PD-L1 expression (P < 0.05). Survival was significantly influenced by tumor location, histopathological subtype, degree of differentiation, PD-L1 expression, and tumor size, with tumor size being the most critical factor (P < 0.05). Conclusion: Our findings suggest that PD-L1 positivity is notably prevalent in signet ring cell carcinoma of the pancreas and is strongly associated with poor survival outcomes. Given these results, further studies with larger patient cohorts are warranted to validate these observations and explore potential therapeutic implications.

SUMMARY OBJECTIVE Analyze the over expression of neural precursor cell expressed developmentally down-regulated protein 9 (NEDD-9) deregulated associated with a poor prognosis in various carcinomas. Our objective was to investigate the relationship between the levels of NEDD-9, CA 15-3, and CEA and PET (SUVmax, MTV40, TLG40) with the clinical parameters of patients with breast cancer (BC). METHODS One hundred and eleven patients (82 BC patients who underwent 18F-FDG PET/CT and 29 healthy controls) were evaluated. SUVmax, MTV, and TLG of the primary tumor were compared with the molecular and histopathological subtypes. 18F-FDG, MTV, and TLG were evaluated based on the clinical data, i.e., nodal involvement, distant metastasis, ER and PR status, Ki-67, serum levels of NEDD-9, CA15-3, and CEA. We compared the NEDD-9 in the BC and healthy control groups. RESULTS The mean ± SD of SUVmax in the 82 patients was 13.0 ± 8.6. A statistically significant relationship (p = 0.022) was found between the molecular subtypes and 18F-FDG uptake. The relationship between 18F-FDG uptake and TLG measured in patients <50 years, ER-PR negativity, and HER2 positivity were statistically significant (p=0.015, 0.007, 0.046, and 0.001, respectively). MTV40, TLG40, and CA 15-3 in metastatic patients were statistically significant (p=0.004, 0.005, and 0.003, respectively). NEDD-9 in the BC group was significantly higher than in the healthy group (p=0.017). There was a positive correlation between SUVmax and Ki67 and CA 15-3; MTV40 and CEA; CA 15-3, CEA, SUVmax, and MTV40; a negative correlation was found between CEA, TLG40, and age. CONCLUSION The use of SUVmax, MTV40, and TLG40 parameters with NEDD-9 and tumor markers has been shown to provide a high diagnostic, predictive, and prognostic value for the management of BC. This is considered to be the basis of interventions focused on the treatment objectives related to NEDD-9.

Objective: This study aimed to evaluate the impact of anti-epidermal growth factor receptor (anti-EGFR)–based maintenance therapy administered after first-line chemotherapy combined with anti-EGFR treatment on progression-free survival (PFS) and overall survival (OS) in patients with RAS wild-type metastatic colorectal cancer (mCRC), using real-world data. Methods: Patients followed at a single center between 2015 and 2025 were retrospectively analyzed. A total of 37 RAS wild-type patients who achieved disease control after first-line chemotherapy combined with anti-EGFR therapy were included. Patients were divided into a maintenance therapy group (n = 19) and an active surveillance group (n = 18). Survival analyses were performed using the Kaplan–Meier method, groups were compared using the log-rank test, and a landmark approach was applied to minimize immortal time bias. Results: At a median follow-up of 27.4 months, median PFS was 11.4 months in the maintenance group and 5.4 months in the surveillance group, without reaching statistical significance (P = .133). In contrast, median OS was significantly longer in the maintenance group (56.9 months vs. 9.6 months; P = .041). Additionally, higher rates of transition to subsequent lines of therapy were observed in patients receiving maintenance therapy. Conclusion: Anti-EGFR–based maintenance therapy was associated with numerically prolonged PFS and improved treatment continuity in patients with RAS wild-type mCRC. Although a significant difference in OS was observed, this finding should be interpreted cautiously given the limited sample size, retrospective design, and potential influence of selection bias and subsequent therapies. Larger prospective studies are warranted to better define the role of anti-EGFR maintenance therapy in clinical practice. Cite this article as: Çokgezer S, Artan S, Topuz S, et al. Effect of maintenance anti-EGFR therapy on survival in RAS wild-type metastatic colorectal cancer: real-world data. Cerrahpaşa Med J 2026, 50, 0069, doi: 10.5152/cjm.2026.26069.