Real-Life Multicenter Experience of Venetoclax in Combination with Hypomethylating Agents in Previously Untreated Adult Patients with Acute Myeloid Leukemia in Greece.

BACKGROUND: The landscape of first-line treatment for acute myeloid leukemia (AML) patients ineligible for intensive chemotherapy has changed remarkably after venetoclax approval. Accumulating real-world data further apprises us with more knowledgeable use. To assess the efficacy and safety challenges in the real-life setting of the combination of hypomethylated agent (HMA) and venetoclax, we conducted a multi-center retrospective study. METHODS: Forty adult AML patients treated with the combination of HMA and venetoclax as a first-line treatment after full approval (2020) were included. To confirm VIALE-A results, this group was compared to a historical cohort of 17 chemotherapy-ineligible AML patients treated with HMA monotherapy before 2020. RESULTS: The combination of HMA-venetoclax achieved a composite complete response rate of 86.8% (p < 0.001), median overall survival, and event-free survival of 33.8 and 19.7 months, respectively, in a median follow-up of 17.8 months (pos < 0.001, HR = 0.276, CI: 0.132-0.575, pEFS = 0.004, HR = 0.367, CI: 0.174-0.773). High rates of neutropenia (90%) and consequent infection rates (57.5%) were noted. Only 55% of our patients received antifungal prophylaxis, as its use remains controversial, and invasive fungal infections were presented in 7.5%. CONCLUSIONS: Evidently, venetoclax-HMA yields high response rates and profound survival benefits in real life and has changed our approach to alternative chemotherapy options.

Bone Marrow Iron Stores Are Not Associated with Increased Risk for Invasive Fungal Infections in Patients with Newly Diagnosed Acute Leukemia or Myelodysplastic Syndrome in Transformation: Is There a Relationship?

Iron plays an important role in the pathogenesis of infections, including invasive fungal infections (IFIs). Studies suggested that iron overload might represent an additional risk factor for IFIs among patients with hematological malignancies. We conducted a prospective, multi-center study amongst adult patients with newly diagnosed acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) in transformation to determine whether baseline iron overload as measured using the bone marrow iron store (BMIS) score is an independent risk factor for the development of IFIs. We also measured baseline serum iron and ferritin levels. A total of 98 patients were enrolled (76 with AML) and were followed for 12 months. Twenty-two patients developed IFI during the follow-up period (invasive aspergillosis n = 16, candidemia n = 5, mucormycosis n = 1). A baseline BMIS score ≥ 3 indicated that iron overload was relatively common (38/98 patients, 38%), and its frequency was comparable between patients with no IFIs (31/76, 40.7%) and in those with IFIs (8/22, 36.4%). Univariate analysis showed that only the presence of AML was associated with increased risk for IFIs [OR (95% CI) 7.40 (1.05-325.42)]. Both univariate and multivariate analyses showed that an increased BMIS score (≥3) at baseline was not an independent risk factor for IFIs. Similarly, there was no difference in serum iron and ferritin between the two groups that had similar demographic characteristics. Indices of iron overload were not independent risk factors for IFIs in our cohort of Greek patients with newly diagnosed AML/MDS in transformation.

Improved survival of patients with primary plasma cell leukemia with VRd or daratumumab-based quadruplets: A multicenter study by the Greek myeloma study group.

We evaluated the efficacy and prognostic impact of bortezomib-lenalidomide triplet (VRd) or daratumumab-based quadruplets (DBQ) versus previous anti-myeloma therapies, that is, bortezomib standard combinations (BSC) or conventional chemotherapy (CT), in a large cohort of patients with primary plasma cell leukemia (pPCL), including those fulfilling the revised diagnostic criteria, that is, circulating plasma cells (cPCS): ≥5%; 110 pPCL patients (M/F: 51/59; median age 65 years, range: 44-86) out of 3324 myeloma patients (3%), registered in our database between 2001 and 2021, were studied; 37% had cPCS 5%-19%; 89% received novel combinations including DBQ (21%), VRd (16%) and BSC (52%); 35% underwent autologous stem cell transplantation. 83% achieved objective responses. Treatment with VRd/DBQ strongly correlated with a higher complete response rate (41% vs. 17%; p = .008). After a median follow-up of 51 months (95% CI: 45-56), 67 patients died. Early mortality was 3.5%. Progression-free survival was 16 months (95% CI: 12-19.8), significantly longer in patients treated with VRd/DBQ versus BSC/CT (25 months, 95% CI: 13.5-36.5 vs. 13 months 95% CI: 9-16.8; p = .03). Median overall survival (OS) was 29 months (95% CI: 19.6-38.3), significantly longer in patients treated with VRd/DBQ versus BSC/CT (not reached vs. 20 months, 95% CI: 14-26; 3-year OS: 70% vs. 32%, respectively; p < .001; HzR: 3.88). In the multivariate analysis VRd/DBQ therapy, del17p(+) and PLT <100.000/µL, independently predicted OS (p < .05). Our study has demonstrated that in the real-world setting, treatment with VRd/DBQ induces deep and durable responses and is a strong prognostic factor for OS representing currently the best therapeutic option for pPCL.

Real world data on the prognostic significance of monocytopenia in myelodysplastic syndrome.

Monocytopenia is a common finding in patients with myelodysplastic syndrome (MDS), but although monocytes may exhibit prognostic significance in MDS due to their role in innate immunity, they have not been incorporated in any prognostic scoring system for MDS. In this study, we analyzed national registry data from 1719 adults with MDS. Monocytopenia was present in 29.5% of the patients and was correlated with the presence of excess blasts and higher revised international prognostic scoring system categories. Univariate analysis showed that monocytopenia was prognostic of a lower overall survival [(OS), 32.0 versus 65.0 months, p < 0.001], while it retained its prognostic significance in a multivariate model comprising anemia, neutropenia and thrombocytopenia [hazard ratio (HR) for OS, 1.320, p < 0.001]. Moreover, it was prognostic of a lower leukemia free survival (LFS) both in univariate analysis and in a multivariate model comprising cytopenias, bone marrow blasts, and cytogenetic risk (HR for LFS 1.27, p = 0.031). The findings regarding OS and LFR were exclusive or more pronounced in lower risk patients, respectively. Moreover, monocytopenia could divide the low and intermediate risk groups of IPSS-R in prognostically distinct subgroups. Our results redefine the prognostic role of monocytes in MDS and set the basis for further studies to validate our results and expand our knowledge on the prognostic significance of monocytopenia in MDS.

Real-life Experience With Rituximab-CHOP Every 21 or 14 Days in Primary Mediastinal Large B-cell Lymphoma.

BACKGROUND/AIM: Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL), whose prognosis has greatly improved since the incorporation of the anti-CD20 monoclonal antibody rituximab into current therapeutic regimens. Evidence, however, on the optimal time interval between consecutive chemoimmunotherapy (CIT) cycles is still scarce. This study aimed to evaluate the efficacy outcomes of the more commonly administered 3-weekly regimens to the biweekly ones in a PMLBCL patients' population, who were mostly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone every 21 days (R-CHOP-21) or R-CHOP-14. PATIENTS AND METHODS: We retrospectively studied our cohort of consecutively treated PMLBCL patients, focusing on their treatment density, in order to determine possible differences in treatment outcomes. RESULTS: CIT, in the form of both R-CHOP-21 as well as R-CHOP-14 (or similar regimens), is highly active in PMLBCL, with low rates of early treatment failure. In our cohort of patients, R-CHOP-14 did not result in a meaningful improvement of freedom from progression (FFP) or overall survival (OS). CONCLUSION: Both R-CHOP-14 and R-CHOP-21 are probably equally effective in PMLBCL, yet further, prospective, randomized studies are warranted to clarify whether dose-dense regimens can be associated with better disease control and long-term results.

Identification of Very Low-Risk Subgroups of Patients with Primary Mediastinal Large B-Cell Lymphoma Treated with R-CHOP.

BACKGROUND: R-CHOP can cure approximately 75% of patients with primary mediastinal large B-cell lymphoma (PMLBCL), but prognostic factors have not been sufficiently evaluated yet. R-da- EPOCH is potentially more effective but also more toxic than R-CHOP. Reliable prognostic classification is needed to guide treatment decisions. MATERIALS AND METHODS: We analyzed the impact of clinical prognostic factors on the outcome of 332 PMLBCL patients ≤65 years treated with R-CHOP ± radiotherapy in a multicenter setting in Greece and Cyprus. RESULTS: With a median follow-up of 69 months, 5-year freedom from progression (FFP) was 78% and 5-year lymphoma specific survival (LSS) was 89%. On multivariate analysis, extranodal involvement (E/IV) and lactate dehydrogenase (LDH) ≥2 times upper limit of normal (model A) were significantly associated with FFP; E/IV and bulky disease (model B) were associated with LSS. Both models performed better than the International Prognostic Index (IPI) and the age-adjusted IPI by Harrel's C rank parameter and Akaike information criterion. Both models A and B defined high-risk subgroups (13%-27% of patients [pts]) with approximately 19%-23% lymphoma-related mortality. They also defined subgroups composing approximately one-fourth or one-half of the patients, with 11% risk of failure and only 1% or 4% 5-year lymphoma-related mortality. CONCLUSION: The combination of E/IV with either bulky disease or LDH ≥2 times upper limit of normal defined high-risk but not very-high-risk subgroups. More importantly, their absence defined subgroups comprising approximately one-fourth or one-half of the pts, with 11% risk of failure and minimal lymphoma-related mortality, who may not need more intensive treatment such as R-da-EPOCH. IMPLICATIONS FOR PRACTICE: By analyzing the impact of baseline clinical characteristics on outcomes of a large cohort of patients with primary mediastinal large B-cell lymphoma homogeneously treated with R-CHOP with or without radiotherapy, we developed novel prognostic indices which can aid in deciding which patients can be adequately treated with R-CHOP and do not need more intensive regimens such as R-da-EPOCH. The new indices consist of objectively determined characteristics (extranodal disease or stage IV, bulky disease, and markedly elevated serum lactate dehydrogenase), which are readily available from standard initial staging procedures and offer better discrimination compared with established risk scores (International Prognostic Index [IPI] and age-adjusted IPI).

Positron emission tomography after response to rituximab-CHOP in primary mediastinal large B-cell lymphoma: impact on outcomes and radiotherapy strategies.

End-of-treatment (EoT) PET/CT is used as a guide to omit radiotherapy (RT) patients with primary mediastinal large B-cell lymphoma (PMBCL). We present the mature and extended results of a retrospective study evaluating the prognostic significance of EoT-PET/CT after adequate response to R-CHOP. Among 231 consecutive PMLBCL patients, 182 underwent EoT-PET/CT and were evaluated according to the Deauville 5-point scale (D5PS) criteria. Freedom from progression (FFP) was measured from the time of PET/CT examination. Among 182 patients, 72 (40%) had D5PS score 1 (D5PSS-1), 33 (18%) had 2, 28 (15%) had 3, 29 (16%) had 4, and 20 (11%) had 5. The 5-year FFP was 97, 94, 92, 82, and 44% for D5PSS-1, D5PSS-2, D5PSS-3, D5PSS-4, and D5PSS-5, respectively. Among 105 patients with unequivocally negative PET/CT (D5PSS-1/D5PSS-2), 49 (47%) received RT (median dose 3420 cGy) and 56 (53%) did not with relapses in 0/49 vs. 4/56 patients (2 mediastinum and 2 isolated CNS relapses).The 5-year FFP for those who received RT or not was 100% versus 96%, when isolated CNS relapses were censored (p = 0.159). Among D5PSS-3 patients (27/28 irradiated-median dose 3600 cGy), the 5-year FFP was 92%. The 5-year FFP for D5PSS-4 and D5PSS-5 was 82 and 44%; 44/49 patients received RT (median dose 4000 and 4400 cGy for D5PSS-4 and D5PSS-5). Our study supports the omission of RT in a sizeable fraction of PET/CT-negative patients and definitely discourages salvage chemotherapy and ASCT in patients with PMLBCL who conventionally respond to R-CHOP, solely based on PET/CT positivity in the absence of documented progressive or multifocal disease. The persistence of positive PET/CT with D5PSS < 5 after consolidative RT should not trigger the initiation of further salvage chemotherapy in the absence of conventionally defined PD.

Carfilzomib-induced endothelial dysfunction, recovery of proteasome activity, and prediction of cardiovascular complications: a prospective study.

Carfilzomib (CFZ) improves survival in relapsed/refractory multiple myeloma but is associated with cardiovascular adverse events (CVAEs). We prospectively investigated the effect of CFZ on endothelial function and associations with CVAEs. Forty-eight patients treated with Kd (CFZ 20/56 mg/m2 and dexamethasone) underwent serial endothelial function evaluation, using brachial artery flow-mediated dilatation (FMD) and 26S proteasome activity (PrA) measurement in PBMCs; patients were followed until disease progression or cycle 6 for a median of 10 months. FMD and PrA decreased acutely after the first dose (p < 0.01) and FMD decreased at cycles 3 and 6 compared to baseline (p ≤ 0.05). FMD changes were associated with CFZ-induced PrA changes (p < 0.05) and lower PrA recovery during first cycle was associated with more prominent FMD decrease (p = 0.034 for group interaction). During treatment, 25 patients developed Grade ≥3 CVAEs. Low baseline FMD (HR 2.57 lowest vs. higher tertiles, 95% CI 1.081-6.1) was an independent predictor of CVAEs. During treatment, an acute FMD decrease >40% at the end of first cycle was also independently associated with CVAEs (HR = 3.91, 95% CI 1.29-11.83). Kd treatment impairs endothelial function which is associated with PrA inhibition and recovery. Both pre- and posttreatment FMD predicted CFZ-related CVAEs supporting its role as a possible cardiovascular toxicity biomarker.

The effect of 5-azacytidine treatment delays and dose reductions on the prognosis of patients with myelodysplastic syndrome: how to optimize treatment results and outcomes.

The regimen of 5-azacytidine for patients with myelodysplastic syndrome (MDS) has remained unchanged since its first approval. Although several modifications have since been made and delays and dose reductions are common especially during the first treatment cycles, there are minimal data on the prognostic effect of these modifications. In this study, based on data from 897 patients with MDS treated with 5-azacytidine recorded in a national registry, the effect of treatment delays and dose reductions on response, transformation to acute myeloid leukaemia, and survival (after 5-azacytidine initiation, OST ) were analysed. Delays during the first two cycles were noted in 150 patients (16·7%) and were found to adversely affect OST independently of the International Prognostic Scoring System score [hazard ratio (HR), 1·368; P = 0·033] or pre-existing neutropenia (HR, 1·42; P = 0·015). In patients achieving a response, delays before response achievement were correlated with its type (complete remission, 2·8 days/cycle; partial remission, 3·3 days/cycle; haematologic improvement, 5·6 days/cycle; P = 0·041), while delays after response achievement did not have any effect on retention of response or survival. Dose reductions were found to have no prognostic impact. Based on our results, treatment delays especially during the first cycles should be avoided, even in neutropenic patients. This strict strategy may be loosened after achieving a favourable response.

Real-world effectiveness and safety of ixazomib-lenalidomide-dexamethasone in relapsed/refractory multiple myeloma.

Real-world data on regimens for relapsed/refractory multiple myeloma (RRMM) represent an important component of therapeutic decision-making. This multi-centric, retrospective, observational study conducted by the treating physicians evaluated the effectiveness and safety of ixazomib-lenalidomide-dexamethasone (IRd) in 155 patients who received ixazomib via early access programs in Greece, the UK, and the Czech Republic. Median age was 68 years; 17% had an Eastern Cooperative Oncology Group performance status ≥ 2; median number of prior therapies was 1 (range 1-7); 91%, 47%, and 17% had received prior bortezomib, thalidomide, and lenalidomide, respectively. Median duration of exposure to ixazomib was 9.6 months. Overall response rate was 74%, including 35% very good partial response or better (16% complete response). Median progression-free survival (PFS) was 27.6 months (27.6 and 19.9 months in patients with 1 or > 1 prior lines, respectively). IRd treatment for ≥ 6 months was associated with longer PFS (hazard ratio 0.06). Fourteen patients (9%) discontinued IRd due to adverse events/toxicity in the absence of disease progression. Peripheral neuropathy was reported in 35% of patients (3% grades 3-4). These findings support the results of the phase III TOURMALINE-MM1 trial in a broader real-world RRMM population.

Characteristics of Long-Term Survival in Patients With Myelodysplastic Syndrome Treated With 5-Azacyditine: Results From the Hellenic 5-Azacytidine Registry.

BACKGROUND: Hypomethylating agents have altered the prognosis of myelodysplastic syndrome (MDS) so that long-term survival is now a feasible treatment goal. PATIENTS AND METHODS: We analyzed data from patients with MDS treated with 5-azacytidine recorded in the Hellenic 5-azacytidine registry. We divided patients, on the basis of their survival after 5-azacytidine initiation (OST), in groups of long-term survivors (Q3 and P90 group with OST above the third quartile and the 90th percentile of the whole group, respectively) and short-term survivors comprising the remaining patients, and compared the characteristics between the groups. The study included 626 patients, 157 in the Q3 group and 63 in the P90 group. RESULTS: Categorization per the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), and World Health Organization-based prognostic scoring system (WPSS) was found to predict long-term survival, while multivariate analysis revealed that response to 5-azacytidine was the strongest predictor of long-term survival. Nevertheless, patients with hematologic improvement (HI) and stable disease (SD) were equally distributed in the groups of short- and long-term survival. CONCLUSION: SD should not be considered a poor treatment response and should not be grouped with failure, while HI offers similar prognosis to SD and thus should not be grouped with complete and partial remission. Patients with SD should continue treatment with 5-azacytidine.

The prognostic significance of chromosome 17 abnormalities in patients with myelodysplastic syndrome treated with 5-azacytidine: Results from the Hellenic 5-azacytidine registry.

In patients with myelodysplastic syndrome (MDS), the prognostic significance of chromosome 17 abnormalities has not yet been fully elucidated, except for isochromosome 17q that has been characterized as an intermediate risk abnormality in the Revised International Prognostic Scoring System (IPSS-R). To further characterize the prognostic significance of chromosome 17 abnormalities we analyzed the hematologic and prognostic characteristics of 548 adult patients with MDS treated with 5-azacytidine through the Hellenic 5-azacytidine registry and found 32 patients with a chromosome 17 abnormality (6 with i[17q], 15 with -17, 3 with add[17p] and the rest with other rarer abnormalities, mostly translocations). The presence of a chromosome 17 abnormality was correlated with poor prognostic features (high IPSS, IPSS-R, and WPSS scores) and a low overall survival rate (15.7 vs 36.4 months for patients without chromosome 17 abnormalities, Kaplan-Meier, Log Rank P < 0.00001), but these results were confounded by the fact that most (92.3%) of the cases with a chromosome 17 abnormality (with the exception of i(17q) that was found in all cases as an isolated abnormality) were found in the context of a complex karyotype. Nevertheless, one should not ignore the contribution of chromosome 17 abnormalities to the prognostic significance of a complex karyotype since 33.8% of complex karyotypes encompassed a chromosome 17 abnormality.

Effectiveness and Safety of Micafungin in Managing Invasive Fungal Infections among Patients in Greece with Hematologic Disorders: The ASPIRE Study.

INTRODUCTION: Invasive candidiasis (IC) can be a life-threatening infection in immunocompromised patients, particularly those with cancer, hematologic diseases and/or hematopoietic stem cell transplantation (HSCT) recipients. The objective of this study was to evaluate the effectiveness of micafungin in patients with hematologic malignancies or HSCT recipients, relevant to clinical presentation of IC, in real-life practice in Greece. METHODS: ASPIRE was a phase IV, multicenter, non-interventional, prospective cohort study, conducted at ten tertiary hospitals in Greece, in adults with hematologic disease. Micafungin treatment for IC or prophylaxis for Candida infection was administered per standard clinical practice until a clinical outcome (success or failure) was reached. Treatment success was defined by the EORTC/MSG criteria for invasive fungal infections (IFI) and was assessed by the investigator. Treatment discontinuation and safety were also evaluated. RESULTS: One hundred forty-three patients were enrolled. Median age was 62; 85 (59.4%) patients were male, and 133 (93.0%) had Greek ethnicity. One hundred twenty-six (88.1%) patients had hematologic malignancies, and 21 (14.7%) had received HSCT. Prophylaxis was administered to 74 (51.7%) patients [median (range) dose: 50 (50-150) mg/day] with no signs of IFI. Overall, 52 (36.4%) patients with possible IFI at baseline received micafungin treatment [100 (50-125) mg/day] versus 12 (17.2%) with probable [100 (75-150) mg/day] and 5 (3.5%) with confirmed [125 (100-150) mg/day] IFI. Treatment success was 91.6% (95% CI 85.80-95.59; n = 131) overall and 90.5% (n = 67) in patients receiving prophylaxis. Median time on treatment was 13 days. Treatment discontinuation (n = 26; 18.2%) was not related to adverse events. No treatment-related serious adverse events were reported. CONCLUSION: Micafungin treatment for IC or prophylaxis for Candida infection was effective and well tolerated in patients with hematologic disorders in clinical practice in Greece. These results demonstrate that micafungin could be used more widely for prophylaxis. Further work is required to determine the efficacy and safety of micafungin for the management of IFIs in hematologic settings. FUNDING: Astellas Pharma Inc.

Correction to: Real-world data on Len/Dex combination at second-line therapy of multiple myeloma: treatment at biochemical relapse is a significant prognostic factor for progression-free survival.

The original version of this article contained a mistake. The name of Eirini Katroditou should have been Eirini Katodritou. The original article has been corrected.

Real-world data on Len/Dex combination at second-line therapy of multiple myeloma: treatment at biochemical relapse is a significant prognostic factor for progression-free survival.

We evaluated progression-free survival (PFS) rate of patients treated with lenalidomide/dexamethasone (Len/Dex), the efficacy of the combination, and the prognostic significance of treatment at biochemical vs. clinical relapse on PFS in 207 consecutive myeloma patients treated with Len/Dex in second line, according to routine clinical practice in Greece. First-line treatment included bortezomib-based (63.3%) or immunomodulatory drug-based (34.8%) therapies; 25% of patients underwent autologous stem cell transplantation. Overall response rate was 73.4% (17.8% complete response and 23.7% very good partial response); median time to best response was 6.7 months. Overall, median PFS and 12-month PFS rate was 19.2 months and 67.6%, respectively. 67.5% of patients had biochemical relapse and 32.5% had clinical relapse prior to initiation of Len/Dex. Median PFS was 24 months for patients treated at biochemical relapse vs. 13.2 months for those treated at clinical relapse (HR:0.63, p = 0.006) and the difference remained significant after adjustment for other prognostic factors. Type of relapse was the strongest prognostic factor for PFS in multivariate analysis. These real-world data confirm the efficacy of Len/Dex combination at first relapse; more importantly, it is demonstrated for the first time outside a clinical trial setting that starting therapy with Len/Dex at biochemical, rather than at clinical relapse, is a significant prognostic factor for PFS, inducing a 37% reduction of the probability of disease progression or death.

Real-world data on prognosis and outcome of primary plasma cell leukemia in the era of novel agents: a multicenter national study by the Greek Myeloma Study Group.

We have studied the efficacy and the prognostic impact of novel agents in 50 primary plasma cell leukemia (pPCL) patients registered in our database. Eighty percent of patients were treated upfront with novel agent-based combinations; 40% underwent autologous stem cell transplantation (ASCT). Objective response rate was 76; 38% achieved at least very good partial response (≥vgPR) and this correlated significantly with bortezomib-based therapy plus ASCT. At the time of evaluation, 40 patients had died. Early mortality rate (≤1 month) was 6%. Median progression-free survival (PFS) and overall survival (OS) were 12 months and 18 months respectively, both significantly longer in patients treated with bortezomib-based therapy + ASCT vs. others (PFS: 18 vs. 9 months; p = 0.004, OS: 48 vs. 14 months; p = 0.007). Bortezomib-based therapy + ASCT predicted for OS in univariate analysis. In multivariate analysis, achievement of ≥vgPR and LDH ≥ 300 U/L were significant predictors for OS. These real-world data, based on one of the largest reported national multicenter series of pPCL patients treated mostly with novel agents support that, among the currently approved induction therapies, bortezomib-based regimens are highly effective and reduce the rate of early mortality whereas in combination with ASCT consolidation they prolong OS.

Point-prevalence survey of healthcare facility-onset healthcare-associated Clostridium difficile infection in Greek hospitals outside the intensive care unit: The C. DEFINE study.

BACKGROUND: The correlation of Clostridium difficile infection (CDI) with in-hospital morbidity is important in hospital settings where broad-spectrum antimicrobial agents are routinely used, such as in Greece. The C. DEFINE study aimed to assess point-prevalence of CDI in Greece during two study periods in 2013. METHODS: There were two study periods consisting of a single day in March and another in October 2013. Stool samples from all patients hospitalized outside the ICU aged ≥18 years old with diarrhea on each day in 21 and 25 hospitals, respectively, were tested for CDI. Samples were tested for the presence of glutamate dehydrogenase antigen (GDH) and toxins A/B of C. difficile; samples positive for GDH and negative for toxins were further tested by culture and PCR for the presence of toxin genes. An analysis was performed to identify potential risk factors for CDI among patients with diarrhea. RESULTS: 5,536 and 6,523 patients were screened during the first and second study periods, respectively. The respective point-prevalence of CDI in all patients was 5.6 and 3.9 per 10,000 patient bed-days whereas the proportion of CDI among patients with diarrhea was 17% and 14.3%. Logistic regression analysis revealed that solid tumor malignancy [odds ratio (OR) 2.69, 95% confidence interval (CI): 1.18-6.15, p = 0.019] and antimicrobial administration (OR 3.61, 95% CI: 1.03-12.76, p = 0.045) were independent risk factors for CDI development. Charlson's Comorbidity Index (CCI) >6 was also found as a risk factor of marginal statistical significance (OR 2.24, 95% CI: 0.98-5.10). Median time to CDI from hospital admission was shorter with the presence of solid tumor malignancy (3 vs 5 days; p = 0.002) and of CCI >6 (4 vs 6 days, p = 0.009). CONCLUSIONS: The point-prevalence of CDI in Greek hospitals was consistent among cases of diarrhea over a 6-month period. Major risk factors were antimicrobial use, solid tumor malignancy and a CCI score >6.