Rational: Circulating tumor cells (CTCs) appear to be a promising tool for predicting the clinical outcome and monitoring the response to treatment in patients with solid tumors. The current study assessed the clinical relevance of monitoring CTCs in patients with metastatic castration resistant prostate cancer (mCRPC) treated with cabazitaxel. Patients and Methods: Patients with histologically confirmed mCRPC who were previously treated with a docetaxel-containing regimen and experienced disease progression were enrolled in this multicenter prospective study. CTC counts were enumerated using the CellSearch system at baseline (before cabazitaxel initiation), after one cabazitaxel cycle (post 1st cycle) and at disease progression (PD). Patients were stratified into predetermined CTC-positive and CTC-negative groups. The phenotypic characterization was performed using double immunofluorescence staining with anti-CKs and anti-Ki67, anti-M30 or anti-vimentin antibodies. Results: The median PFS and OS were 4.0 (range, 1.0–17.9) and 14.5 (range, 1.2–33.9) months, respectively. At baseline, 48 out of 57 (84.2%) patients had ≥1 CTCs/7.5 mL of peripheral blood (PB) and 37 (64.9%) had ≥5 CTCs/7.5 mL of PB. After one treatment cycle, 30 (75%) out of the 40 patients with available measurements had ≥1 detectable CTC/7.5 mL of PB and 24 (60%) ≥ 5CTCs/7.5 mL of PB; 12.5% of the patients with detectable CTCs at the baseline sample had no detectable CTCs after one treatment cycle. The detection of ≥5CTCs/7.5 mL of PB at baseline and post-cycle 1 was associated with shorter PFS and OS (p = 0.002), whereas a positive CTC status post-cycle 1 strongly correlated with poorer OS irrespective of the CTC cut-off used. Multivariate analysis revealed that the detection of non-apoptotic (CK⁺/M30⁻) CTCs at baseline is an independent predictor of shorter OS (p = 0.005). Conclusions: In patients with mCRPC treated with cabazitaxel, CTC counts both at baseline and after the first cycle retain their prognostic significance, implying that liquid biopsy monitoring might serve as a valuable tool for predicting treatment efficacy and survival outcomes.

New treatment modalities have been recently introduced in the management of ovarian cancer (OC). Herein, we sought to investigate their implementation in routine clinical practice and examine the real-world management of OC in Greece. EpOCa was a non-interventional, multicenter, retrospective study in patients with advanced epithelial OC. The primary outcome was to estimate the proportions of the different treatment regimens used per line of therapy, while progression-free survival (PFS) and overall survival (OS) were the key secondary endpoints. A total of 154 patients were enrolled in the study, among whom, 40% were tested for BRCA mutations and 30% were found to be positive. Nearly 90% of patients underwent debulking surgery at diagnosis, with few operations being also recorded upon relapse. Platinum-based chemotherapy (CT) was predominantly used in the first line with half of patients also receiving angiogenesis inhibitor (AI), while non-platinum-based CT was preferred in later lines. The median PFS was 18.2 and 8.8 months in the first- and second-line setting, respectively, whereas the median OS was approximately 50 months. Our study adds to the available, but limited, real world data on the management of ovarian cancer providing evidence regarding the applied treatment strategies and outcomes of patients in Greece.

Introduction: Circulating immune cells serve as readily accessible biomarkers in cancer patients. Some of them, such as neutrophils, lymphocytes as well as the neutrophil to lymphocyte ratio (NLR), have been validated as prognostic indicators of disease outcome whereas the significance of others remains controversial due to conflicting findings. Moreover, the interplay and correlation among these markers have not been thoroughly investigated nor has their dynamic course during chemotherapy. Methods: Blood was collected from 16 healthy donors and 90 patients receiving first line chemotherapy for metastatic colorectal cancer before, during and after chemotherapy. Neutrophils, lymphocytes, circulating CD4 ⁺ CD25 ⁺ FOXP3 ⁺ regulatory T lymphocytes (Tregs), monocytic myeloid derived suppressor cells (mMDSCs), polymorphonuclear myeloid derived suppressor cells (pMDSCs) and other exploratory myeloid subsets were immunophenotyped and quantified with flow cytometry. Their frequencies were compared between healthy donors and patients and correlated with each other and with clinical parameters. Associations with progression-free and overall survival were evaluated using Cox proportional hazards regression and longitudinal changes in immune cell populations during chemotherapy were analyzed using linear mixed-effects models. Results: Circulating Tregs were significantly reduced in patients with high neutrophil counts (7% vs 17%, p=0.04), increased significantly during treatment in responders, particularly in patients achieving complete or partial response (+16%, p = 0.003) but did not demonstrate prognostic significance. pMDSCs were further stratified by CD16 expression into a CD16 ⁺ subset associated with favorable outcome and a CD16 ^dim/− subset enriched in patients demonstrating poor prognosis. Frequency of circulating mMDSCs was modestly increased in patients but retained adverse prognostic significance (HR 1.98, CI 1.04-3.78, p= 0.039) and correlated with the CD16 ^dim/− pMDSC fraction. Mature CD15 ⁺ CD33 ^- polymorphonuclear cells were significantly expanded in patients (79% vs 73%, p= 0.003) and correlated with adverse clinical features, whereas lower levels correlated with improved survival (HR 0.54, CI 0.3-0.98, p= 0.045). Rare HLA-DR ⁺ CD16 ⁺ granulocytic subset demonstrated significantly reduced levels in patients compared to healthy donors while their kinetics during treatment also correlated inversely with disease burden. Discussion: Circulating immune cell subsets in metastatic colorectal cancer exhibit considerable baseline heterogeneity and distinct immune kinetics during chemotherapy. Our findings demonstrate that conventional leukocyte populations, when evaluated individually, together with detailed immunophenotyping provide complementary prognostic information, revealing previously unappreciated heterogeneity within major immune cell populations and a network of novel interrelationships among circulating immune cells. Together, these observations support comprehensive immune profiling as a promising approach for future biomarker development and immune-based patient stratification.