P1109: epidemiology of cutaneous t-cell lymphomas: data analysis from the marche multidisciplinary team (mdt) register.

Topic: 18. Indolent and mantle-cell non-Hodgkin lymphoma - Clinical Background: Cutaneous T cell lymphomas (CTCL) represent a rare and heterogeneous group of lymphomas that present in the skin without extracutaneous manifestations at the time of diagnosis. Data on the epidemiology of CTCL are primarily based on patient cohorts seen in these expert centers, frequently influenced by referral bias. Several epidemiological studies have been reported, but no epidemiologic data are currently available in Italy. The Marche multidisciplinary team (MDT) for diagnosis and follow up of cutaneous lymphomas was formed 27 years ago with the aim of sharing the management of these rare disorders. Aims: One of the main goals of the MDT was to register the number and types of cutaneous lymphomas across Marche in order to estimate the incidence as well as survival rate and other outcome data. Methods: All patients with a histologically confirmed diagnosis of cutaneous lymphoma were referred by participants of MDT to the Clinic of Hematology, Polytechnic University of Marche in Ancona (Italy), for clinical evaluation, staging, treatment and follow up. The cases were registered anonymously and dynamically with follow up reporting. The TNMB classification according to modified ISCL/EORTC revision from 2011 was employed. The study was approved by the human research ethics committee of “AOU delle Marche” Hospital and prior written informed consent was obtained from all participants. Statistical analysis was performed using JMP 14.0 and significance was defined as P value <.05. Results: During the study period (1995–2020), 492 patients with newly diagnosed CTCL were reported and evaluated. Mycosis fungoides (MF) accounted for 73.2% of CTCL, followed by primary cutaneous CD30+ LPDs (8.3%) and Sezary Syndrome (5.1%). Among rare T-cell lymphomas, primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder encompassed the 3.4% of the cases. In the entire observation period mentioned, there has been a continual increase in reports, probably mainly due to increased reporting activity, number of Centres reporting, and attention to this pathology. CTCL showed a moderately higher prevalence in men than in women (M: F = 2,3: 1) and median age at diagnosis was 62 years (range, 10-90), with significative differences reported between subtype. More than 80% had an early-stage disease (IA, IB and IIA) at diagnosis and median time from first skin lesion to diagnosis, was 21 months (range, 0-562.9), higher in early phase disease than advanced stage (22.1 months vs 7.8 months, respectively; pV=0.04). Stage resulted as best predictor of survival. In a median follow up of 67 months (range, 5.7-308.6), combined 5-years survival rate was 86.73%, poorer for advanced compared to early stages (48.7% and 94.2%, respectively; pV <0.001) (Figure 1). Conclusion: The real epidemiology of CTCL is still a matter of debate. Currently, the Italian Cutaneous Lymphoma Study-Group (ICLSG-named Commissione Linfomi Cutanei) effort is to create a national register for CTCL, based on MDT registry, to provide information from a national perspective. The increase in patients diagnosed with these relatively new and rarer diagnostic entities relates to more accurate diagnosis, followed by a more “personalized” management.Keywords: Cutaneous T-cell lymphoma, Epidemiology