Background and Objectives: Total neoadjuvant therapy (TNT) for locally advanced rectal cancer (LARC) offers significant advantages in terms of pathologic response and long-term survival; however, it is still unclear which patients will benefit the most from this treatment. This study aims to investigate the role of metabolic parameters on pretreatment positron emission tomography–computed tomography (PET/CT) images in predicting treatment response after TNT. Materials and Methods: The research was conducted using a single-center, retrospective design. Patients treated with total neoadjuvant therapy are included if they have locally advanced rectal cancer (cT3/T4-N0 or cTany-N1/N2). The patient group was categorized into two groups: CR and non-CR. Clinicopathologic features, PET/CT parameters, CA19-9, and CEA values were compared between these two groups. Results: In total, 52 patients were included. The CR group had 21 patients, and the non-CR group had 31 patients. The analysis demonstrated that the CR group had significantly lower metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than the non-CR group (p = 0.022 vs. p = 0.003, p < 0.05). Also, CA19-9 values were lower than the non-CR group, and this difference was statistically remarkable (p = 0.40, p < 0.05). Conclusions: MTV and TLG parameters in PET/CT for pretreatment staging and pretreatment blood CA 19-9 levels are prognostic factors for predicting treatment response, and they may play a crucial role in choosing treatment. Comprehensive research is warranted on this subject with a larger patient population.

Background: Mucosal malignant melanoma (MMM) is a rare and aggressive malignancy with a dismal prognosis. While the Systemic Immune-Inflammation Index (SII) has emerged as a prognostic marker in various solid tumors, its specific value in MMM remains undefined. This study investigated the association between pretreatment SII and overall survival (OS) in patients with MMM. Methods: We retrospectively analyzed 106 adults with histologically confirmed MMM treated at six oncology centers in Turkey between 2005 and 2025. The baseline SII was calculated as platelet × neutrophil/lymphocyte counts obtained before definitive treatment. A receiver operating characteristic (ROC) analysis identified an optimal SII cutoff of 776 for overall survival (OS), defining low (<776) and high (≥776) SII groups. Results: Gastrointestinal and head and neck mucosa were the most frequent primary sites, and one-third of patients presented with metastatic disease. The median OS for the entire cohort was 23.3 months. Patients with a high versus low SII had a shorter OS (16.2 vs. 35.2 months; HR 2.71, 95% CI 1.67–4.40; p < 0.001). In multivariable analysis, a high SII (HR 1.88, 95% CI 1.12–3.14; p = 0.016), gastrointestinal primary site (HR 1.99, 95% CI 1.23–3.23; p = 0.005), and metastatic disease at diagnosis (HR 4.01, 95% CI 2.32–6.94; p < 0.001) independently predicted a worse OS. Conclusions: The SII is a novel, independent prognostic biomarker in MMM. Elevated pretreatment SII correlates with aggressive clinicopathologic features and inferior survival. As a readily accessible and cost-effective marker, SII may facilitate improved risk stratification in routine clinical practice for MMM patients.

Background and Objectives: This study aimed to evaluate the prognostic impact of baseline body composition measurements and changes in muscle and adipose tissue during treatment on overall survival (OS) in metastatic non-small cell lung cancer (NSCLC) patients treated with nivolumab. Materials and Methods: Eighty-eight metastatic NSCLC patients who were initiated on nivolumab between January 2022 and December 2024 were retrospectively analyzed. Body composition parameters were derived from baseline and 3-month ¹⁸F-FDG PET/CT scans at the L3 level, including psoas muscle index (PMI), skeletal muscle index (SMI), intramuscular adipose content (IMAC), and subcutaneous fat density (SFD). Treatment-related changes in body composition were evaluated, and survival analyses were performed using Kaplan–Meier estimates and Cox regression models. Results: Overall, 34.1% (n = 30) of patients were classified as sarcopenic. Median OS was significantly longer in non-sarcopenic patients (19 months vs. 5 months, p < 0.001). In univariate analysis, older age, higher comorbidity burden, liver metastasis, baseline sarcopenia, and adverse treatment-related changes in muscle and nutritional parameters were found to be associated with OS. In multivariate analysis, only unfavorable changes in skeletal muscle (ΔSMI; HR 3.39, p = 0.003) and subcutaneous fat radiodensity (ΔSFD; HR 2.45, p = 0.02) remained independent adverse prognostic factors. Baseline body composition parameters did not maintain their independence in multivariate models. Conclusions: Our study demonstrates that muscle loss or insufficient gain and unfavorable changes in subcutaneous fat radiodensity during nivolumab treatment more strongly predict overall survival compared to baseline measurements. These findings highlight the clinical importance of monitoring dynamic body composition throughout treatment, rather than static assessments, in NSCLC patients receiving immunotherapy.

Background/Objectives: This study aimed to evaluate the prognostic value of ¹⁸F-FDG PET/CT-based secondary lymphoid organ metabolic ratios—spleen/liver (SLR), bone marrow/liver (BLR), and ileocecal region/liver (ILR)—and hematological inflammation markers (neutrophil/lymphocyte ratio [NLR] and systemic immune-inflammation index [SII]) obtained before nivolumab treatment in relation to survival in patients with advanced non-small cell lung cancer (NSCLC). Methods: This retrospective single-center study included 79 advanced NSCLC patients who were treated with nivolumab monotherapy at Marmara University Faculty of Medicine Hospital between 2022 and 2024. Pretreatment SLR, BLR, and ILR ratios were calculated from ¹⁸F-FDG PET/CT examinations; NLR and SII values were obtained from hematological data. Survival outcomes were analyzed using the Kaplan–Meier method, and prognostic factors were assessed using Cox proportional hazards regression analysis. In a subset of patients, an exploratory longitudinal analysis was performed using early follow-up PET/CT to assess follow-up-to-baseline changes in immune-organ metabolic ratios in relation to overall survival. Results: High NLR and SII levels were significantly associated with shorter progression-free survival and overall survival. In contrast, no significant associations were observed between PET/CT-derived metabolic ratios (SLR, BLR, and ILR) and survival. Multivariate analysis identified the presence of liver metastases and a high NLR as independent adverse prognostic factors for overall survival. Conclusions: In this homogeneous real-world cohort treated exclusively with single-agent nivolumab, PET/CT-derived secondary lymphoid organ metabolic ratios showed limited prognostic value at baseline and during early on-treatment assessment. In contrast, hematological inflammation markers, especially high NLR levels, are strong prognostic indicators of survival and may complement established clinical factors in risk stratification.

Objective: To determine the frequency and distribution of genomic alterations detected by plasma-based next-generation sequencing(NGS) in metastatic lung adenocarcinoma in a real-world setting.Patients and Methods: This retrospective single-center study included 76 patients with histologically confirmed metastatic lungadenocarcinoma who underwent plasma circulating tumor DNA (ctDNA) NGS between March 2021 and July 2024. Targetedsequencing was performed using a 28-gene panel. Genomic alterations were classified as actionable according to current clinicalguidelines. Concordance with available tissue-based molecular testing was evaluated in the internal cohort.Results: At least one genomic alteration was detected in 43/76 patients (56.6%). Among NGS-positive patients, 19/43 (44.2%) had ≥2alterations. Actionable alterations were identified in 24/76 patients (31.6%;55.8% of NGS-positive cases). The most frequently alteredgenes were TP53 (35.5%), EGFR (18.4%), and KRAS (13.2%). In an exploratory survival analysis of internal NGS-positive patients(n=19), median overall survival (OS) was 27 vs 29 months for patients with and without actionable alterations, respectively (p=0.94).Conclusion: Plasma-based NGS identifies clinically relevant genomic alterations in metastatic lung adenocarcinoma and complementstissue-based molecular testing in routine practice.