Family History Of Hematologic Malignancies and Disorders In a Population Based Study Of Myelodysplastic Syndromes (MDS)

Background MDS is a clonal hematopoietic stem cell disorder characterized by dysplastic changes in the bone marrow, ineffective hematopoiesis and an increased risk for developing acute myeloid leukemia (AML). The majority of MDS cases are sporadic, but rare familial cases have been described and are often ascertained through clinic-based referrals. To our knowledge, no population based study of MDS has examined the frequency of family history of hematologic malignancies and disorders in patients, nor associations with disease characteristics and outcomes. Methods Newly diagnosed MDS cases are being identified by rapid case ascertainment by the Minnesota Cancer Surveillance System (MCSS), a population-based cancer registry in Minnesota. Eligibility criteria include all newly diagnosed cases of MDS during the period April 1, 2010-October 31, 2014, between 20-85 years, Minnesota resident, and ability to understand English or Spanish. Proxy interviews are not being conducted. Medical records and biologic samples are obtained and questionnaires are filled out by participants. Centralized pathology and cytogenetics review confirm diagnosis and classify by subtype and risk score including the Revised International Prognostic Scoring System (IPSS-R). Since 2010, information on family history has been obtained through questionnaire responses and/or medical record review on 353 MDS patients. Cases were considered to have a positive family history if they reported a first degree relative with MDS, leukemia, lymphoma or other hematologic condition (multiple myeloma [n=4], Waldenstrom’s macroglobulinemia [n=1] and idiopathic thrombocytopenic purpura [n=1]). Treatment related MDS cases were excluded leaving 330 MDS patients for analysis. Unconditional logistic regression was used to calculate crude odds ratios (ORs) and 95% confidence intervals (CI) overall and by sex. Results A total of 61/330 (18.5%) cases reported a family history of a hematologic condition. The mean age at diagnosis was 71.3 years in those with a family history compared to 72.2 years in those without a family history (p=0.53). There was no difference in the sex distribution between the two groups. Though not statistically significant, the odds of having abnormal cytogenetics or an IPSS-R of High/Very High was lower for those having a positive family history (OR 0.57 [CI 0.25-1.33, p=0.19 and 0.67 [CI 0.24-1.84, p=0.29], respectively). The odds of survival at one year after diagnosis was significantly higher in those with a family history (OR 2.79 [CI 1.04-7.51, p=0.04]) compared to those without (Table). Further stratification by sex revealed that this association was strongest for males (OR=4.23, [CI 0.94-19.0, p=0.06] compared to females (OR=1.84 [CI=0.47-7.19, p=0.38]). Discussion In this population based study of adults with MDS, the prevalence of MDS cases having a positive family history was higher than previous reports. Additionally, cases reporting a family history of hematologic malignancies and disorders appear to experience lower risk disease and have significantly improved overall survival, especially males. It is possible that patients with a family history of hematologic conditions are diagnosed earlier in the course of their disease secondary to increased awareness about blood disorders and/or more active screening within the family. Our analysis is limited by relatively small numbers, but enrollment is ongoing so subsequent analyses with larger numbers of subjects may be more revealing. Additionally, a prospective study to examine these families further, including detailed medical histories and collection of biospecimens (saliva, blood, skin) for genetic analyses is underway in order to identify potential mechanisms and mutations involved in the development of MDS and progression to AML. Disclosures: No relevant conflicts of interest to declare.