[Clinical Features and Prognosis of Acute T-cell Lymphoblastic Leukemia in Children--Multi-Center Data Analysis in Fujian]

OBJECTIVE

To evaluate the efficacy of acute T-cell lymphoblastic leukemia (T-ALL) in children and explore the prognostic risk factors.

METHODS

The clinical data of 127 newly diagnosed children with T-ALL admitted to five hospitals in Fujian province from April 2011 to December 2020 were retrospectively analyzed, and compared with children with newly diagnosed acute precursor B-cell lymphoblastic leukemia (B-ALL) in the same period. Kaplan-Meier analysis was used to evaluate the overall survival (OS) and event-free survival (EFS), and COX proportional hazard regression model was used to evaluate the prognostic factors. Among 116 children with T-ALL who received standard treatment, 78 cases received the Chinese Childhood Leukemia Collaborative Group (CCLG)-ALL 2008 protocol (CCLG-ALL 2008 group), and 38 cases received the China Childhood Cancer Collaborative Group (CCCG)-ALL 2015 protocol (CCCG-ALL 2015 group). The efficacy and serious adverse event (SAE) incidence of the two groups were compared.

RESULTS

Proportion of male, age≥10 years old, white blood cell count (WBC)≥50×109/L, central nervous system leukemia, minimal residual disease (MRD)≥1% during induction therapy, and MRD≥0.01% at the end of induction in T-ALL children were significantly higher than those in B-ALL children (P <0.05). The expected 10-year EFS and OS of T-ALL were 59.7% and 66.0%, respectively, which were significantly lower than those of B-ALL (P <0.001). COX analysis showed that WBC≥100×109/L at initial diagnosis and failure to achieve complete remission (CR) after induction were independent risk factors for poor prognosis. Compared with CCLG-ALL 2008 group, CCCG-ALL 2015 group had lower incidence of infection-related SAE (15.8% vs 34.6%, P =0.042), but higher EFS and OS (73.9% vs 57.2%, P EFS=0.090; 86.5% vs 62.3%, P OS=0.023).

CONCLUSIONS

The prognosis of children with T-ALL is worse than children with B-ALL. WBC≥100×109 /L at initial diagnosis and non-CR after induction (especially mediastinal mass has not disappeared) are the risk factors for poor prognosis. CCCG-ALL 2015 regimen may reduce infection-related SAE and improve efficacy.

[Clinical Characteristics and Prognosis of MLL Rearranged Childhood Acute Lymphocyte Leukemia]

AbstractObjective: To investigate the clinical characteristics and prognostic factors in childhood acute lymphoblastic leukemia with MLL gene-rearrangement-positive (MLL-r+ ALL).

METHODS

The clinical data of 1 414 newly diagnosed children with ALL admitted to five hospital in Fujian province from April 2011 to December 2020 were retrospectively analyzed. The clinical characteristics and efficacy of MLL-r+ and MLL-r- subgroup were compared. The prognostic factors of MLL-r ALL were analyzed by COX regression model.

RESULTS

Among all children with ALL, the proportion of patients aged less than 1 year old was 1.8%, and the detection rate of MLL-r+ was 3.4% (48/1 414). The positive detection rate of MLL-r in the age groups <1 year old, and ≥1 year old and ≤14 years old was 38.5% (10/26) and 2.7 (38/1 388), respectively, the difference was statistically significant (P<0.000). Compared with MLL-r- group, the MLL-r+ group had a higher proportion of patients with age <1 year, white blood cell (WBC) count ≥50×109/L, combined central nervous system leukemia (CNSL) and testicular leukemia(TL), while MRD <0.01% on d 33 or d 46 of induction chemotherapy was lower (all P<0.05). The expected 10-year event free survival(EFS) rate and overall survival(OS) rate of the MLL-r+ group were significantly lower than those of the MLL-r- group （EFS： 49.9% vs 77.0%； OS: 55.3% vs 82.9%， P<0.05). COX regression model analysis showed that age <1 year, minimal residual disease (MRD) ≥0.01% on d 33 or d 46 of induction chemotherapy were independent risk factors for worse OS and EFS in MLL-r+ ALL patients (all P<0.05).

CONCLUSION

Age <1 year old, high WBC, concomitant CNSL and TL are more common in children with MLL-r+ ALL at initial diagnosis, with poor early treatment response and long-term prognosis. Age <1 year old at initial diagnosis and MRD positive after induction chemotherapy may be risk factors for poor prognosis.

[Comparison of the Early Efficacy and Serious Adverse Events between CCCG-ALL 2015 and CCLG-ALL 2008 in the Treatment of Pediatric Patients with Acute Lymphoblastic Leukemia]

OBJECTIVE

To evaluate the early efficacy and serious adverse events (SAE) related to chemotherapy of different protocols in the treatment of pediatric patients with acute lymphoblastic leukemia (ALL), so as to improve the overall survival rate.

METHODS

A comparison of the early efficacy and SAE was performed between pediatric patients treated with Chinese Children Cancer Group-ALL 2015 (CCCG-ALL 2015) protocol from January 2019 to June 2020 and those treated with Chinese Children Leukemia Group-ALL 2008 (CCLG-ALL 2008) protocol from January 2017 to December 2018.

RESULTS

The remission rate before consolidation chemotherapy between the two groups was not significantly different (P=0.198), but the negative conversion rate of minimal residual disease (MRD) in CCLG-ALL 2008 group was significantly higher than that in CCCG-ALL 2015 group (P=0.000). The incidence of SAE in CCCG-ALL 2015 group was significantly lower than that in CCLG-ALL 2008 group (P=0.021), and the incidence of infection-related SAE was significantly higher in the latter (P=0.001), while the difference of non-infection-related SAE was not statistically significant (P=0.623). In addition, the treatment-related mortality in CCCG-ALL 2015 group was significantly lower than that in CCLG-ALL 2008 group (P=0.003).

CONCLUSION

CCCG-ALL 2015 regimen reduces the intensity of chemotherapy, which can significantly decrease the chemotherapy-related SAE (especially infection-related SAE), as well as treatment-related mortality. However, the MRD negative conversion rate is low before consolidation treatment, and the overall long-term efficacy remains to be further observed.

[Children's NK/T Cell Lymphoma-Associated Hemophagocytic Syndrome: Clinical Analysis of 6 Cases]

OBJECTIVE

To study the clinical features, treatment and prognosis of patients with NK/T cell lymphoma-associated hemophagocytic syndrome(NK/T-LAHPS).

METHODS

Retrospective analysis was used to explore the clinical data of 6 children with NK/T-LAHPS who were admitted in Department of Pediatric Hematology of Fujian Medical University Union Hospital from July 2012 to June 2016. The 6 patients included 4 boys and 2 girls, with a median age of 4 years(range 1.75 to 11). In 4 patients the hemophagocytic syndrome(HPS) occurred as the main primary manifestations of underlying lymphoma, in the other 2 patients HPS occurred during lymphoma progression. The clinical manifestations included persistent fever(6/6), hepatomegaly(6/6), splenomegaly(6/6) and pancytopenia(6/6). Laboratory data indicated that the level of ferritin(2179-15000 ng/ml) , LDH(608-3899 IU/L) and EBV-DNA(>10⁵ copies/ml ) was elevated obviously. The other common clinical features of NK/T-LAHPS were hypoproteinemia(6/6), hepatic dysfunction(5/6), hypofibrinogenimia(5/6), hypertriglyceridemia(3) and hemophagocytosis in bone marrow(5/6).

RESULTS

After being treated according to the HLH-2004 protocol combined with supported therapy for 1 or 2 weeks, all the patients achieved a clinical response, and the laboratory indicators of HPS were improved. The combined chemotherapy of SMILE was given to 4 patients timely, among them 2 patients achieved complete remission(CR) and long term survival, 1 patient achieved partial remission(PR) and died of relapse after drug withdrawal and 1 patient died of aggravated lymphoma. The other 2 patients did not receive chemotherapy in time, HPS relapsed quickly, because of the progression of lymphoma, and all died of severe hepatic dysfunction and coagulopathy.

CONCLUSION

The NK/T-LAHPS is an invariably fatal disease with poor prognosis, and typically occurrs at the advanced stage or the terminal phase of the disease. HLH-2004- based protocol in combination with comprehensive therapy is hopeful for the patients with NK/T-LAHPS, which may delay the disease progression and provide opportunities for the treatment of primary disease. Once the laboratory indicators of HPS are improved, it is important to treat lymphoma timely with the combined chemotherapy of SMILE, which is significant for improving the prognosis.