Case–control study of risk factors of myelodysplastic syndromes according to World Health Organization classification in a Chinese population

Abstract

Risk factors of mydelodysplastic syndromes (MDS) remain largely unknown. We conducted a hospital-based case-control study consisting of 403 newly diagnosed MDS patients according to World Health Organization classification and 806 individually gender and age-matched patient controls from 27 major hospitals in Shanghai, China, to examine relation of lifestyle, environmental, and occupational factors to risk of MDS. The study showed that all MDS (all subtypes combined) risk factors included anti tuberculosis drugs [odds ratio (OR) IntroductionMyelodysplastic syndromes (MDS) represent a heterogeneous group of neoplastic clonal stem cell disorders characterized by clinical presentations of anemia, thrombocytopenia, and leucopenia. MDS may be categorized into subtypes according to histological, immunological, and genetic characteristics. MDS was usually diagnosed by French-American-British (FAB) classification with subtypes including refractory anemia (RA), RA with ringed sideroblasts (RARS), RA with excess of blasts (RAEB), RAEB in transformation (RAEB-T), and chronic myelomonocytic leukemia (CMML) [1]. Since its publication in 2001, World Health Organization (WHO) classification for MDS has become widely adopted [2]. In the WHO MDS system, blast cutoff is less than 20% compared to 30% in FAB system. Additional WHO MDS subtypes include refractory cytopenia with multiple dysplasia (RCMD), MDS with isolated del(5q), and MDS unclassifiable (MDS-u) and the WHO MDS system does not include CMML [3].Secondary MDS is usually resulted from radiation and chemotherapy. Little is known about the etiology of primary or de novo MDS. Most previous studies on MDS risk factors focused on FAB MDS [4][5][6]. Here, we report a large hospital-based case-control study of 403 WHO MDS cases and 806 age and sex-matched controls in a Chinese population to assess effects of lifestyle, environmental, and occupational factors on MDS development.

Myelodysplastic syndromes in South America: A multinational study of 1080 patients

“…Among northeastern patients, 50% were from rural zones and half of the cases were rural workers (data not shown). Farmers without protection devices, which are common in developing countries, are constantly exposed to these chemicals associated with MDS etiology [22]. A previous work that evaluated clinical characteristic of MDS from Ourense, Spain, where 70% of patients lived in rural environments, showed a frequency of 35% of RARS patients [38], consistent with the higher frequency of this subtype among Brazilian patients.…”

“…The incidence and clinical characteristics of patients with MDS varies by geographical area, and this has been attributed to genetic or ethnic, occupational, lifestyle, and environmental factors, that have not been fully elucidated [9,22]. Socioeconomic status may also influence the outcome of the disease [23].…”

“…3). The median age at diagnosis seems to vary in different countries, being lower in "Eastern" than in "Western" countries: 59 years old in China [22], 60 in Japan [24], 58 in Korea [25], 56 in Thailand [26], and 65 in Taiwan [27], 77 in US [28], 72-73 in Germany [15,16,29], and 65-71 in Italy [15,16,30,31]. However, a new report using a population-based registry data showed a median age of 76 years for Japan [32].…”

“…Although RCMD without RS and RCMD-RS entities were merged in the 2008 WHO classification [3], we differentiated them in Table I to point out that more evident differences were observed in the pure RARS subtype. RARS accounts for 1.5-12% of MDS patients and occurs primarily in older cases with median age of 60-73 years [3,22,[33][34][35] and more frequent in male than females [3,33] or with a similar sex ratio [34,35]. The median age for pure RARS subtype, which accounted for 5.0% of the whole series, was 70 years old (mean age: 67 years) with a M/F ratio of 0.8 and was detected in 2.5, 10.4, and 1.2% of Ar, Br and Ch cases, respectively.…”

Occupational, dietary, and other risk factors for myelodysplastic syndromes in Western Greece

“…Exposure to agricultural chemicals has been studied extensively as a risk factor, and most studies indicate a positive association with MDS [6,7,8,9,10,11,12], although in some others, no significant association was found [13,14]. A recent meta-analysis of 11 case-control studies confirmed a significant association between MDS and exposure to pesticides.…”