[Cdc37 Expression in Multiple Myeloma and Its Role in Cell Proliferation].

OBJECTIVE: To investigate the expression of cell division cycle protein 37 (Cdc37) in multiple myeloma (MM) and its effect on MM cell proliferation. METHODS: The expression of Cdc37 mRNA in CD138+ cells derived from 63 newly diagnosed MM patients and 8 healthy people were detected by real-time quantitative PCR (RT-qPCR). Cdc37 was down-regulated by lentivirus in MM cell line NCI-H929. CCK-8 assay and soft agar clone formation assay were conducted to explore the role of Cdc37 on MM proliferation in vitro. To further verify the effect of Cdc37 on MM cell proliferation in vivo, NOD/SCID mice subcutaneous tumorigenesis model was established. Flow cytometry was carried out to explore the role of Cdc37 on cell cycle. Cell cycle associated proteins and NF-κB pathway were detected by Western blot (WB). RESULTS: Cdc37 was highly expressed in newly diagnosed CD138+cells compared with healthy people. After Cdc37 suppression by shRNA lentivirus infection in NCI-H929 cells, the proliferation of MM cells were decreased in vitro and in vivo. Compared with the control group, the ratio of cells arrested in G0/G1 phase significantly increased in NCI-H929-Cdc37 shRNA cells, the expression of cyclin D1 decreased, while the expression of p21 and p53 was significantly up-regulated. Meanwhile, the activation of NF-κB signaling pathway was hampered in NCI-H929-Cdc37 shRNA cells. CONCLUSION: Cdc37 is highly expressed in newly diagnosed MM patients. Inhibition of Cdc37 results in decreased proliferation activity and G0/G1 arrest in NCI-H929 cells. The possible mechanism may be to inhibit the activation of NF-κB signaling pathway.

[Clinical Analysis of Patients with MGUS, Primary Light Chain Amyloidosis, Multiple Myeloma or Multiple Myeloma with Concurrent Amyloidosis].

OBJECTIVE: To summarize and compare the clinical baseline characteristics of patients with monoclonal gammopathy of undetermined significance (MGUS), primary light chain amyloidosis (pAL), multiple myeloma (MM), or MM with concurrent amyloidosis, especially the differences in cytogenetic abnormalities. METHODS: The clinical data of 15 cases of MGUS, 34 cases of pAL, 842 cases of MM and 23 cases of MM with concurrent amyloidosis were analyzed and compared retrospectively. RESULTS: Cytogenetic statistics showed that the incidence of t (11; 14) in the four groups (MGUS vs pAL vs MM vs MM with concurrent amyloidosis) was 0%, 33.3%, 16.4%, and 15.8%, respectively (P=0.037); that of 13q deletion was 20.0%, 14.7%, 45.8% and 56.5%, respectively (P<0.001); gain of 1q21 was 50.0%, 12.5%, 47.4% and 40.9%, respectively (P=0.001). Proportion of pAL patients with 0, 1 and≥2 cytogenetic abnormalities (including 13q deletion, 17p deletion, 1q21 amplification and IgH translocation) accounted for 41.9%, 41.9% and 16.1%, respectively; while the proportion of the same category in MM was 17.6%, 27.3%, and 55.2% respectively; this ratio of MM with concurrent amyloidosis was more similar to MM. Subgroup analysis showed that genetic abnormalities (including 13q deletion, 17p deletion and 1q21 amplification) were comparable within t (11; 14) negative and positive groups. Compared with positive cases, t(11; 14) negative patients with MM or MGUS were more likely to have 13q deletions and multiple genetic abnormalities. CONCLUSION: Clinical characteristics of pAL, especially cytogenetic abnormalities, are significantly different from MM with concurrent amyloidosis. It suggests that although the onset characteristics are similar, actually the two diseases belong to different disease subtypes which should be carefully predicted and identified.

IgH translocation with undefined partners is associated with superior outcome in multiple myeloma patients.

BACKGROUND: In multiple myeloma (MM), impact of specific chromosomal translocations involving IgH (14q21 locus, including t(4;14), t(11;14), and t(14;16)) has been explored extensively. However, over 15% MM patients harboring IgH translocation with undefined partners have long been ignored. METHODS: A prospective non-randomized cohort study with a total of 715 newly-diagnosed MM cases was conducted, 13.6% of whom were t(14;undefined) positive. The whole cohort was divided into four groups: no IgH split (47.7%); t(14;undefined) (13.6%); t(11;14) (17.6%); and t(4;14) or t(14;16) group (21.1%). RESULTS: Median OS for the four groups was 84.2, not reached (NR), 58.7, and 44.2 months, respectively, with P values for t(14;undefined) vs no IgH split, t(11;14), and t(4;14)/t(14;16) groups of 0.197, 0.022, and 0.001, respectively. In bortezomib-based group, the survival advantage gained by t(14;undefined) group was much more significant compared to t(11;14) and t(4;14)/t(14;16) groups. Importantly, t(14;undefined) turned out to be an independent predictive factor for longer OS of MM patients in multivariate analysis, especially in the context of bortezomib treatment. Similar results were also observed in the PUMCH external validation cohort. CONCLUSION: Collectively, our data confirmed and externally validated the favorable prognosis of the t(14;undefined) groups, especially in the era of novel agents.

[Clinical Analysis of B-CLPD with Cytopemia as the Predominant Characteristic].

OBJECTIVE: To investigate the clinical characteristics and therapeutic responte of patients with B-CLPD mainly manifested as cytopenia, so as to deeply understand this disease. METHODS: The clinical data of 13 B-CLPD patients with hematocytopenia as main manifestation, and the absolute count of lymphocytes＜5×109/L, absence of hepatosplenic lymph-nodes and extramedullary invasion tin our department fron 2003 to 2018 were analyzed retrospectively. The clinical characteristics, therapeutic efficacy and adverse reactions of 3 patients were summarized. RESULTS: The median age of patients was 59 (43-76) years old, the median of lymphocyte was 1.86 (0.69-4.8) ×109/L, the levels of LDH and ß2-microglubulin were normal in most patients, the monolineage and multilencage hematopoietic failure of different degrees existed in most all patients. The lymphocyte ratio in patients was 18.5%-94.0%, CD20 was positive in all patients, and yet the CD5-positive and CD-negative existed in 7 and 6 cases respectively. There was no significant difference in ratio of lymphocyte invasion among different immunophemtype. The FISH detection showed that there were no high risk genetic types. 92.3% of patients received rituximab treatment, most of them received chemotherapy of rituximab combined with C0P/CHOP like regimen, only 2 patients received fludarabine for comparatively short course. The analysis indicated that 8 out of 13 patients showed a certain theropeutic efficacy, however the drug-related hematopoietic suppression occurred in both 2 patients treated with fludarabin. CONCLUSIONS: The B-CLPD accompanied with hematocytopenia often displays bone marrow hypohematopoiesis of different degree and easily confuses with the congenital and acquired hemotopoietic faiture diseases. The rituximab treatment may be more appropreate for these patients, but for patients received chemotherapy containing fludarabin, the persistant hematopoietic failure must be especially watched out.

Secretory status of monoclonal immunoglobulin is related to the outcome of patients with myeloma: a retrospective study.

The treatment of multiple myeloma (MM) with proteasome inhibitor (PI) bortezomib has significantly improved the survival of patients with MM. The 26S proteasome inhibitor targets the unfolded protein response (UPR) by inhibiting proteasome degradation of ubiquitinated paraprotein, subsequently leading to the lethal accumulation of paraprotein within the endoplasmic reticulum. According to secretory status of monoclonal immunoglobulin, newly diagnosed MM (NDMM) is divided into measurable and unmeasurable disease, which includes oligosecretory, nonsecretory, and nonproducer myeloma. The present study analyzed the clinical characteristics of 822 patients with NDMM who had either measurable or unmeasurable diseases and received bortezomib- or thalidomide-based therapies. Our results showed that the median progression-free survival (PFS) and overall survival (OS) of patients with MM was significantly longer in patients with measurable disease than those in oligosecretory, nonsecretory, and nonproducer MM (PFS: 27, 18, 19, and 2.0 months, respectively [P < .001]; OS: 51, 30, 22, and 2.0 months, respectively [P < .001]). Within the unmeasurable group, patients with nonproducer myeloma showed the shortest PFS and OS. Importantly, compared with thalidomide treatment, bortezomib significantly improved the PFS and OS of patients with MM with measurable disease (PFS: 25 and 33 months [P = .022], respectively; OS: 41 and 58 months [P < .001], respectively), but not those with unmeasurable disease (PFS: 18 and 16 months [P = .617], respectively; OS: 22 and 27 months [P = .743], respectively). Our results indicate that bortezomib-based therapy performed no better than thalidomide-based treatment in patients with unmeasurable MM. The results need to be confirmed in other patient cohorts, preferably in the context of a prospective trial.

[Role of miR137-MITF in Prognostic Analysis of Multiple Myeloma].

UNLABELLED: Objectiive：To explore the effect of miR137 target gene MITF on the prognosis of multiple myeloma (MM). METHODS: The target genes of miR137 were predicted by software, the GFP analysis was carried out for detecting MITF as the prognosis of multiple myeloma. The cell line overexpressing miR137 in MM cell line was constructed. Real-time qPCR and Western blot were used to detect the expression of MITF in this cell line. RESULTS: The target genes of miR137 were MITF, BUE2H, SH3BP5 and KLF12. High expression of MITF in MM patients showed a good prognosis according to GFP analysis, but no significant difference was detected between the different subgroups. MITF expression was higher in MM cell line that over expressed miR137. CONCLUSION: The miR137-MITF is an important index in judging the prognosis of multiple myeloma.

[Prognostic value of serum IL-6 in patients with multiple myeloma].

This study was aimed to evaluate the prognostic value of serum IL-6 (sIL-6) in patients with multiple myeloma (MM). The sIL-6 level in 288 patients with MM was retrospectively analyzed, and the clinical characteristics and prognosis in patients with different IL-6 level were compared. The newly diagnosed patients with MM were divided into two groups: the low sIL-6 group (sIL-6 < 100 pg/ml) and the high sIL-6 group (sIL-6 ≥ 100 pg/ml). The results showed that high sIL-6 level was more common in patients with ECOG score>3, myeloma bone disease (MBD) between grade 2 to 4, and high creatinine level. There was no significant differences in age, abnormal karyotype percentage, chromosome 13q14 abnormality percentage, CD138(+)/CD38(+) cells percentage and the level of calcium, phosphorus, albumin, C-reactive protein, ß2-MG, lactate dehydrogenase, hemoglobin, platelet between the two groups at diagnosis, and also no significant difference in response to initial induction chemotherapy among the two groups. The overall survival was significantly different between the low and high IL-6 groups (P = 0.04, 35 m vs 29 m), but no difference in time to progress between the two groups (P = 1.93, 23 m vs 14 m). It is concluded that the sIL-6 level correlates with the clinical characteristics and prognosis. Radioimmunoassay is an appropriate measurement for human IL-6 in serum, and suitable for clinical application.

[Clinical and laboratory features of T-cell prolymphocytic leukemia in China].

OBJECTIVE: To investigate the clinical and laboratory characteristics and survival of Chinese patients with T- cell prolymphocytic leukemia (T-PLL). METHODS: Eleven patients with T-PLL admitted in our hospital from Jan 2006 to Oct 2012 were retrospectively analyzed. RESULTS: Of the 11 patients, nine were males and two females, with the median age of 56.0(19-69) years old. All the patients, except for three, presented with leukocytosis. The incidence of hyperleukocytosis (1/11) was less frequent than that in the British series (75%) (P=0.000). Lymphocyte counts in peripheral blood were increased in 9 of the 11 patients with the median absolute lymphocyte count (ALC) of 17.22(0.58-148.83)×109/L. Superficial lymphadenopathy and splenomegaly were the most common physical signs. It was common that serum lactate dehydrogenase (LDH) and beta 2 microglobulin(ß2-MG)were higher than normal level. All cases were positive for CD2/CD3/CD5/TCRαß, negative for CD1a /HLA-DR and TdT, and most of them were strong positive for CD7 expression. By chromosome analyses, most cases. (9/10) have normal chromosome. This rate is significantly higher than that of the British and American series (3% and 25%, respectively) (P=0.000, P=0.001). The 14q11 abnormality and trisomy 8q, which are common among Western cases, were not observed in any of our cases. With a median follow-up of 23.0 months, three patients died. Two year progress free survival (PFS) and overall survival (OS) were 53.3% and 50%, respectively. There were 3 patients with PFS over a number of years, whether it should be considered as the T-chronic lymphocytic leukemia (T-CLL) is worthy of further studies. CONCLUSION: The common clinical manifestations of T-PLL patients were increased lymphocyte counts and lymphadenopathy as well as splenomegaly. And most cases have high level of blood LDH and ß2- MG and normal chromosome karyotype.

[Clinical feature and efficacy of patients with multiple myeloma and renal impairment treated with bortezomib based chemotherapy].

OBJECTIVE: To explore the efficacy and safety of bortezomib (btz) based chemotherapy in multiple myeloma (MM) patients with renal-function impairment (RI). METHODS: Fifty-six MM patients with impaired renal function treated with bortazomib based regimens in our single center were retrospectively analyzed. RESULTS: The median age was 59 (ranged 30-77) years. 39.3% were κ-restricted MM, while 57.1% were λ-restricted MM. Nine patients were IgD-MM, and 14 were light chain MM. Median creatinine clearance (CrCl) was 25.33 (7.23-59.55) ml/min. The number of patients with mild, moderate and severe RI was 6, 35 and 15, respectively. Overall response rate of MM was 82.4% (≥MR), including 32.4% complete response (CR), 17.6% very good partial response (VGPR) and 26.5% partial response (PR). The rate of renal response was 89.3%, including 62.5% CR, 14.3% PR and 12.5% minor response (MR). A median time of optimal response was 25.5 (ranged 5-240) days. There was no significant difference in the median overall survival and the time to progress in different RI groups. Adverse events observed were similar to those patients with normal renal function previously reported. Most adverse events were manageable, 55.6% patients developed peripheral neuropathy and 10 patients discontinued bortezomib. CONCLUSION: The incidence of RI is higher in patients with IgD-MM and λ restricted MM. Bortezomib based treatment is a highly effective and safe option in MM patients with impaired renal function. In this analysis, renal function was improved in a substantial proportion of patients. Peripheral neuropathy is the major adverse events which limit its use in MM patients.

[Expression of B7-H1 gene in leukemia cells and its clinical significance].

This study was purposed to investigate the expression of B7-H1 gene in leukemia cells and its clinical significance. The expression of B7-H1 mRNA was detected by SYBR Green I real-time quantitative PCR in a panel of 9 leukemia cell lines, 4 leukemia cell lines induced with IFN-γ, the bone marrow mononuclear cells (BMMNC) from 59 initial leukemia patients and 10 dendritic cells (DC) derived from BMMNC of initial leukemia patients, 2 solid tumour cell lines and BMMNC from 10 normal persons. The correlation between the clinical features of 59 acute leukemia patients and the expression level of B7-H1 mRNA in leukemia cells was analyzed. The results showed that the lower level of B7-H1 mRNA expression was found in leukemia cell lines and primary acute leukemia cells, but the expression level of B7-H1 mRNA was up-regulated significantly in the leukemia cell lines induced by IFN-γ and DC derived from BMMNC of leukemia patients. The expression level of B7-H1 mRNA in non complete remission (CR) patients after therapy was significantly higher than that in CR patients. It is concluded that the expression level of B7-H1 mRNA in leukemia cells is lower, but is up-regulated when affected by some factors. A correlation exists between the expression level of B7-H1 gene in leukemia cells and response of patients to therapy.

[The significances of 13q14 deletion for development and prognosis of multiple myeloma].

OBJECTIVE: To determine the incidence and clinical significance of chromosome 13q14 deletion in multiple myeloma (MM). METHODS: Bone marrow samples were collected from 132 newly diagnosed MM patients referred to our hospital. Interphase fluorescence in situ hybridization (i-FISH) combined with magnetic activated cell sorting (MACS) were performed on chromosome 13q14 (RB-1). RESULTS: (1) i-FISH was used to investigate CD138-enriched bone marrow MM cells and revealed a 13q14 deletion rate of 51.5% (68/132), while conventional cytogenetic (CC) analysis revealed 13q deletions/monosomy 13 (Δ13) only of 5.0%(6/120). (2) Univariate analysis showed that 13q14 deletion rate by i-FISH > 25%, bone marrow plasma cells > 50%, ISS stage and ß(2)-MG ≥ 5.5 mg/L were associated with shorter overall survival (OS). Multivariate analysis revealed that 13q14 deletion rate by i-FISH > 25% was an independent unfavorable factor (P = 0.042). (3) Patients treated with bortezomib had a much better response than those treated with traditional chemotherapy (P = 0.001). There was no significant difference in OS between patients received bortezomib with and without 13q14 deletion (P > 0.05), indicating that bortezomib could reverse the poor prognosis of 13q14 deletion. CONCLUSION: (1) i-FISH followed CD138 cell sorting appears to be a highly sensitive method for detecting 13q14 deletion. (2) 13q14 deletion rate by i-FISH > 25% is an independent unfavorable factor. (3) Bortezomib could reverse the poor prognosis of 13q14 deletion.

[Outcome of bortezomib plus chemotherapy with or without stem cell transplantation for treatment of multiple myeloma].

OBJECTIVE: To investigate the efficacy and adverse reaction of bortezomib plus chemotherapy with or without stem cell transplantation (SCT) for treatment of multiple myeloma (MM). METHODS: Thirty-one MM patients were treated with bortezomib plus dexamethasone or thalidomide or DTPACE, followed by SCT. Response to bortezomib was evaluated according to the European Blood and Marrow Transplantation (EBMT) criteria. Adverse events were graded according to the WHO criteria. RESULTS: 1) 5 discontinued the bortezomib therapy because of acute renal failure or acute tumor lysis syndrome and 3 died. In 26 evaluable patients received 99 courses of therapy. The overall response rate (ORR) to bortezomib was 80.8%, and was 100.0% in 15 newly diagnosed patients and 54.6% in 11 relapsed/refractory patients. All of the 6 newly diagnosed patients treated with bortezomib plus DTPACE followed by SCT achieved CR. 2) In 7 newly diagnosed patients completed 8 cycles bortezomib treatment, the diseases were improved more and more with the courses of treatment. Chromosome 13 deletion did not exert a negative impact on response. 3) 6 of 7 patients completed 8 cycles treatment without SCT relapsed in 1-3 month after discontinued therapy; only 1 of 6 such patients received SCT relapsed with the rest keeping on CR at 6-11 month follow-up. 4) The most common adverse events were 1-2 grade and tolerable 3 patients had to reduce the bortezomib dosage because of peripheral neuropathy or sinus bradycardia. CONCLUSION: Bortezomib in combination with chemotherapy with or without SCT is an effective therapy with manageable toxicities for MM patients.

[Analysis of the international staging system of multiple myeloma and its comparison with the DS and IFM staging system in 122 Chinese patients].

OBJECTIVE: To verify applicability of the International Staging System (ISS) for multiple myeloma (MM) to 112 Chinese MM patients and compare ISS with Durie-Salmon (DS) and Intergroup Francophone du Myeloma (IFM) staging system in predicting prognosis. METHODS: 112 previously untreated MM patients in Blood Diseases Hospital of CAMS were analyzed according to ISS retrospectively. RESULTS: 1) Serum beta2-microglobulin (beta2-MG) > or = 3.5 mg/L was an independent adverse prognostic factor for overall survival (OS), and serum albumin <35 g/L predicted for time to progression (TTP), 2) In the 58 cases having cytogenetic data, chromosome 13 aberration (Delta 13) was the only independent adverse prognostic factor for OS; 3) Factors significantly related to serum beta2-MG were serum creatinine, 24h urinary protein,body mass index (BMI) and performance status (PS); and those related to serum albumin were hemoglobin level, percentage of bone marrow plasma cells, lactate dehydrogenase(LDN), fever, PS, class of M-protein, serum phosphorus and BMI; 4) All traditional prognostic factors had no statistical difference between ISS stage II and III excepting for serum beta2-MG and creatinine, and 5/6 Delta 13 patients were classified to ISS stage II; 5) The median OS of ISS stage I, II, III were 69, 23 and 26 months (m) respectively, being no statistical difference between stage II and III; for DS system, 89.5% of patients were classified in stage III, being no statistical difference for OS between the stage I/II and III; while for IFM system, the median OS of low-, intermediate- and high-risk group were 69, 40 and 8 months respectively, being statistically different between high-risk and intermediate/ low-risk groups. CONCLUSIONS: From the result of our limited analysis, the staging of ISS II and III seems unsuitable for Chinese MM patients. The IFM staging system ,which incorporates delta 13, is more effective than ISS, and DS staging system in predicting prognosis.

[The analysis of prognostic variables in 123 patients with multiple myeloma].

OBJECTIVE: To assess the prognostic value of biological features and therapy-related factors in multiple myeloma (MM). METHODS: 123 patients with newly diagnosed MM between January 1998 and May 2005 were enrolled in this retrospective study. Biological features at presentation and therapy-related factors were analysed. The overall survival (OS) and time to progression (TTP) were estimated by Kaplan-Meier analysis and the distribution of OS and TTP were compared using log-rank test. Cox regression was used to identify the independent prognostic factors. RESULTS: (1) The univariate analysis indicated that more immature plasma cells in bone marrow biopsy, C-reactive protein >8. Omg/L, CD117 expression, serum beta2-microglobulin (beta2-MG) (3.5 approximately 5.5 mg/L), abnormal cytogenetics aberration of chromosome 13 (Delta13), hypodiploid, poor response to chemotherapy, interferon(IFN) therapy less than 6 months were associated with shorter OS(P <0.05). Lytic bone lesions at presentation, more immature plasma cells in bone marrow biopsy, serum beta2-MG (3.5 approximately 5.5 mg/L), poor response to chemotherapy, and IFN therapy less than 6 months as well as abnormal cytogenetics, hypodiploid and Delta13 were associated with shorter TTP (P <0.05). (2) Multivariable COX analysis indicated IFN therapy more than 6 months was a protective factor for OS and TTP, and more immature plasma cells in bone marrow biopsy was an independent poor prognostic factor for TTP. CONCLUSION: The morphology of myeloma cells is useful for assessing the prognosis. And IFN therapy more than 6 months could lengthen OS and TTP.

[Cytogenetic characteristics of patients with multiple myeloma in China: analysis of 100 case].

OBJECTIVE: To summarize the cytogenetic characteristics of patients with multiple myeloma (MM) in China and clinical significance thereof. METHODS: Specimens of bone marrow were collected from 100 patients with MM who visited the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences in Tianjin, China. Chromosome banding analysis and fluorescence in situ hybridization (FISH) were conducted. RESULTS: (1) Clonal chromosome aberrations (CA) were detected in 16 of 93 patients (17.2%) by conventional cytogenetics (CC), and when subclonal CA was included CA were detected in 37.0% of the patients. Numerical aberration analysis showed that the most common trisomies were 11, 21, 3, 6, and 12, and the most common monosomies were 16, 13, 8, 22, and 11. Structural aberration analysis showed that the most frequently involved arms were 14q, 8q, 1q, 6q, 11q, 12p, and 1p, and the most frequently involved breakpoints were 14q32, 8q22 - 24, 11q13 - 14, 6p21, 1q10 - 11, and 12p12 - 13. Ploidy level was arranged in decreasing order as: hypodiploidy (46.1%), pseudodiploid (38.5%), hyperdiploidy (18.8%), and tri-/tetraploidy (15.4%). Chromosome 13 abnormality (C13A) was detected in 7 of the 100 patients (7%). The C13A prevalence rates by CC and interphase FISH were 6.0% and 33.3% respectively. Translocations involving chromosome 14 and/or 14q32 aberrations were detected in 6 patients (6.0%). (2) Univariate analysis showed that C13A, nonhyperdiploidy, and clonal CA were associated with significantly shorter overall survival (OS) and time to progression (TTP). Multivariate analysis showed that C13A was the only independent unfavorable factor. CONCLUSION: The concrete CA of the patients with MM in China are comparable to those from Western countries, among which C13A, nonhyperdiploidy, hyperdiploidy, and translocations involving immunoglobulin heavy chain locus (IgH) are recurrent. C13A, nonhyperdiploidy, and clonal CA are associated with shorter OS and time-to-progression, and C13A is the only independent adverse prognostic factor.

[Long-term survival analysis in 170 cases of acute promyelocytic leukemia].

This study was aimed to investigate various factors influencing long-term survival in patients with acute promyelocytic leukemia. A single institutional retrospective study with long-term follow-up was performed to better define the prognostic factors and a rationale for the use of ATRA, chemotherapy, and As(2)O(3) in the treatment of newly diagnosed APL patients. Newly diagnosed patients with APL entering complete remission (CR) were followed up for 6 to 185 months (n = 170) from January 1990 to December 2004. Univariate and multivariate analysis of 8 potential factors influencing survival and prognosis were carried out with Log-Rank and Cox regression method, including sex, age, initial WBC count, the level of lactic hydrogenase (LDH), first induction regimen, time from induction therapy to CR, post-remission therapy, negative or positive rate of PML-RAR alpha and follow-up of reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the estimated 5-year overall survival (OS) and relapse-free survival (RFS) were 80.9% +/- 4.0% and 71.0% +/- 4.0% respectively. The 23 patients relapsed at the median time of 15 months (6 - 70) after CR. Univariate analysis revealed that initial WBC count, first induction regimen, time from induction therapy to CR, type of post-remission therapy and persistent negative RT-PCR in remission were important prognostic factors for long-term survival. Multivariate study demonstrated that only type of post-remission therapy was associated with RFS and OS. It is concluded that the post-remission treatment combining ATRA, As(2)O(3) and chemotherapy would significantly improve the long-term survival of APL patients entering CR(1).