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myelodysplastic syndromes(MDSs), are a heterogeneous group of clonal stem cell disorders characterized by ineffective hematopoiesis and are associated with a high rish of progression to acute leukemia(AL). 40%-60% exists karyotypic abnormality, which plays an important role of MDS in morbidity, diagnosis and the assessment of prognosis. These years, China has used the classification of MDS presented by the French-American-British(FAB) group. Through this classification MDS is divided into five subsets, they are refractory anemia(RA), refractory anemia with ringed sideroblas(RAS), refractory anemia with excess blasts(RAEB), RAEB in transformation(RAEB-t) and chronic myelomonocytic leukemia(CMML). Recently, the World Health Organization(WHO) has published a revised classification of MDS. There is no effective way to cure MDS, especially after transformation to leukemia. It is showed that AL transferred from MDS has lower remission rate and higher recurrence rate than de novo AL.About 21% MDS will eventually transfer into AL, with a preleukemia interval of 9 to 13.7 months according to the study of Western countries and 1 to 45 months in the investigation of Korea. The main subtype of AL transferred from MDS is AML, among which M2 takes the largest part, while M4 and M5 rank the first place. Many risk factors for AL evolution from MDS have been reported, including gender, age, FAB subtype, cytopenia, presence of BM blasts, cytogenetic abnormalities and chemotherapy of high-risk MDS. It is reported that every subtype of MDS is at different phase of evolution to AL, and there is no significant difference between RAEB and AML essentially.Objective: To study the rules of transformation from myelodysplastic syndromes (MDS) into acute leukemias(AL). Between January 1999 to January 2007, a total of 205 consecutive patients with MDS were subjected to a follow-up study. We comparised the cases of post MDS-AML and MDS that hadn’t transferred to AML, and also analyzed these 31 post MDS-AML. There are 119 male and 86 female patients among these 205 cases, whose age varied from 13 to 90. Among these patients, there are 24 male and 7 female of post MDS-AML with the age of 15 to 90.Methods: For scientific comparison to the study of others and objective reflection of MDS’biological feature and clinical correlation, We used the novel WHO classification to divide MDS to RA, RCMD, RARS, RCMD-RS, RAEB-1, RAEB-2, U-MDS and 5q- syndrome. What are observed are as followed: age, sex, blood routine examination, BM cytology examination, BM patho-examination, cytogenetics examination and prognosis. And the specimen of blood routine examination is venous blood and that of peripheral blood cells morphology examination is peripheral blood. The spots of specimen collection of BM cytology examination and BM patho-examination are followed: anterior superior iliac spine, posterior superior iliac spine or breast bone. Using retrospective analytical method, we analyse the clinical characteristics ofpost MDS-AML, that include general document, clinical manifestation, blood routine examination, peripheral blood cells morphology examination, BM cytology examination, BM patho-examination, cytogenetics examination, turnover and prognosis ect. And compare it with contemporary MDS that hasn’t transferred into AML. In the aspect of statistics, we used t test or Fisher’s test to analyze the data.Results: The incidence of AL development among these 205 patients is 15.121%, 4.00% were developed to AL in MDS-RA and 1.25% in MDS-RCMD, while 7.14% in MDS-RAEB-1 and 49.09% in RAEB-2. There was none in other types. The shortest preleukemia interval is 1 month, while the longest is 108 months, with the average of 9.9 month.38.71% patients transferred to ANLL-M2,38.71% to M4, 9.68% to M5, 3.23% to M6, 3.23% to M1, 3.23% to M0, 3.23% to acute lymphoblastic leukemia(ALL). The rate of leukemic transformation of male is much higher than that of female(P<0.05), and that of MDS with more than 0.15 BM blasts is much higher than that of MDS with less than 0.15 BM blasts(P<0.05). The rate in RA is more significant than in RAEB, while the rate in RAEB is bigger than in RAEB-T(P<0.05). The rate of leukemic transformation of MDS with karyotypic abnormality is larger than that with normal chromosome, MDS with chemotherapy’rate is lower than the rate of MDS without chemotherapy, the rate of more than 40y is higher than that of less than 40y and the rate in the MDS with cytopenia is bigger than that without cytopenia. But there are no significant differences between these four groups(P>0.05). Anemia, fever and haemorrhagia are the most common clinical manifestation of post MDS-AML, mostly the PB shows cytopenia more than two series and naive granular leukocytes. 84.8% were hyper-MDS and dyshaematopoiesis was seen in all the cases. 5 patients had karyotypic abnormality. 66.67% were relieved partly or completely, however, 66.7% were relapsed.Conclusion:①The incidence of AL development is 15.12%, 4.00% were developed to AL in MDS-RA and 1.25% in MDS-RCMD, while 7.14% in MDS-RAEB-1 and 49.09% in RAEB-2. There was none in other types. The average preleukemia interval is 9.9 month, the longest one is from MDS-RA.②38.71% patients transferred to ANLL-M2, 38.71% to M4, 9.68% to M5, 3.23% to M6, 3.23% to M1, 3.23% to M0, 3.23% to acute lymphoblastic leukemia(ALL).③The risk factors for AL evolution from MDS were WHO subtype, sex, quantity of BM blasts and cytogenetic abnormalities.④The main clinical manifestation of post MDS-AML was no spefic.⑤The PB of post MDS-AML patients always showed cytopenia in two(45.5%) or three series (48.5%)at first diagnosis, but only erythrocytic series impairment was rare(6%). And we could find naive granular leukocytes. The percentage of cytopenia in three series was higher when MDS transferred to AL(72.7%).⑥Dyshaematopoiesis, especially Erythrocyte with more than 3 nucleus, pseudo Pelger-Huet anomaly and lymph-type small huge-nucleus cell was also significant in AL transferred from MDS.⑦Karyotypic abnormality could occur with the transformation to AL.⑧The remission rate of post MDS-AML after chemotherapy was 66.67%, maybe related to low quantity of cases and that some severe patients gave up therapy. The patients who reach to remission can gain better life quality, but relapsed soon. The recurrence rate was as high as 66.7%.
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