Incidence and Outcome of Myelodysplastic Syndromes in Province of Modena.

Background As in the past Myelodisplastic Syndromes (MDS) were considered preneoplastic conditions, rarely data on these diseases were collected by cancer registries. Thus, there are few well documented population-based studies on the incidence and outcome of MDS. The aim of this study was to collect epidemiological data and clinical characteristics of MDS by studying all cases identified by the Modena Cancer Registry (MCR).

Materials and methods We examined all cases of MDS diagnosed in the Province of Modena (population 633.993 at 2001 Census). MDS from 1997 to 2005 were identified using the MCR database and the archival files of the centralized hemolymphopathological laboratory at Modena Cancer Centre according to ICD-O-3 codes 9980,9982–87,9989. Death certificate, cytology and histology report, both local and national reports of Hospital admission, ICD-9 code reported in medical records were used as sources for identifying new MDS cases and their outcome. After collection, all cases were checked and validated by a hematologist (A.B.) and a pathologist (G.B.) by a review of the original pathology report. The large majority of bone marrow aspirate and biopsy were examined by the same pathologist (G.B.) making diagnostic criteria uniform. Clinical and follow-up data were retrieved by active search of discharge letters, review of hospital records, and interview of general practitioners. Information on vital status was achieved from official population registries. Age standardized rates (ASR) were calculated according to the World Standard population (Doll et al, 1966). The dates of diagnosis and death or the closing date of study (December 2006) were used to estimate survival. Observed survival and relative survival were calculated according to Kaplan-Meier method and the Hakulinen approach, respectively.

Results A total of 205 cases of MDS were identified. The ASR of MDS was 1.2/100,000 varying slightly (from 0.9 to 1.5/100,000; p > 0.05) during the study period, and the crude incidence rate was 3.6/100,000. Median age at diagnosis was 75 years for men and 78 for women. Overall, 58% of patients aged more than 75 years, while only 1% were less than 45 years old. According to French, American and British (FAB) classification there were 35 cases (17% of all MDS) of Refractory Anemia (RA), 51 (25%) of RA with ringed sideroblasts, 73 cases (36%) of RA with excess of blasts (RAEB), 11 (5%) of RAEB in transformation, 31 (15%) of MDS not otherwise specified and 4 (2%) of other MDS. Overall the prognosis of MDS was poor, although we found statistically significant differences by clinical subtypes. In our MDS population the relative survival was 68%, 36% and 26% at 1, 3 and 5 years, respectively.

Conclusions To our knowledge, this study is the first in Italy providing information on the incidence and outcome of MDS using population-based data. Our results confirm that the risk of developing MDS increases with age for both men and women. The incidence of MDS was substantially stable during the study period. Overall survival was poor reflecting the aggressiveness of these diseases and the advanced age of patients at time of diagnosis. As expected, we observed important differences in overall survival by FAB subtypes. In the last few years, innovative treatments for MDS are emerging and we believe that the availability of precise epidemiological data could help clinicians in choosing the most appropriate treatment.