[Characteristics and prognostic effects of NOTCH1/FBXW7 gene mutations in T-cell acute lymphoblastic leukemia...

Objective: To explore the characteristics, clinical features and prognostic effects of NOTCH1/FBXW7 gene mutations in T-cell acute lymphoblastic leukemia (T-ALL) patients. Methods: The clinical data of 61 T-ALL patients who underwent second-generation gene sequencing in Henan Provincial People's Hospital from March 2016 to March 2021 were retrospectively analyzed. There were 46 males and 15 females, with a median age [M (Q₁, Q₃)] of 18 (11, 30) years. The relationship between NOTCH1/FBXW7 gene mutation characteristics, clinical and laboratory parameters and their impact on event free survival (EFS) and overall survival (OS) were analyzed. Results: NOTCH1 gene mutations were found in 34 cases (55.7%, 34/61), including 22 cases of heterodimer domain (HD) mutations (64.7%), 7 cases of proline/glutamate/serine/threonine (PEST) mutations (20.6%), and 5 cases of both HD and PEST mutations (14.7%). FBXW7 gene mutations were detected in 9 cases (14.8%, 9/61), of which 5 cases had both NOTCH1 and FBXW7 gene mutations. Twenty-three (37.7%, 23/61) cases were wild type. The median white blood cell count of patients in NOTCH1/FBXW7 gene mutations group and wild-type group was 76.4×10⁹/L (8.3×10⁹/L, 149.2×10⁹/L), 54.1×10⁹/L (5.3×10⁹/L, 156.6×10⁹/L), respectively. Moreover, the hemoglobin was (89.1±27.1) g/L and (99.5±23.1) g/L, respectively, and the median proportion of bone marrow primordial cells was 84.5% (69.0%, 91.3%) and 60.0%(35.0%, 80.0%), respectively. The gene expression rate of SIL-TAL1, Hox11 and Hox11L2 was 7.9% (3/38) vs 17.4% (4/23), 18.4% (7/38) vs 4.3% (1/23), 5.3% (2/38) vs 13.0% (3/23), respectively (all P>0.05). However, the median platelet level in the NOTCH1/FBXW7 gene mutations group was 60.5×10⁹/L (36.8×10⁹/L, 100.3×10⁹/L), which was lower than that in the wild-type group [116.0×10⁹/L (63.0×10⁹/L, 178.0×10⁹/L)] (P=0.018). The median number of gene mutations in the group with NOTCH1/FBXW7 gene mutations group was 2.5 (1.8, 4.0), which was more than that in the group without NOTCH1/FBXW7 gene mutations group [0 (0, 1.0)] (P<0.001). The median EFS and OS of adult NOTCH1/FBXW7 gene mutations group were 28.0 (95%CI: 7.3-48.7) months and 30.0 (95%CI: 8.9-51.1) months, respectively, which were better than those of adult wild-type group [4.5 (95%CI: 0-11.6) months and 9.0 (95%CI: 0-19.1) months] (P=0.008 and 0.014).The median EFS and OS of children NOTCH1/FBXW7 gene mutations group were 12.0 (95%CI: 10.4-13.6) months and 19.0 (95%CI: 13.6-24.4) months, respectively, and those of wild-type group were 10.0 (95%CI: 8.9-11.1) months and 21.0 (95%CI: 0-51.4) months, respectively (P=0.673 and 0.434). Conclusions: The mutation rate of NOTCH1/FBXW7 gene is higher in T-ALL patients. Patients with NOTCH1/FBXW7 gene mutations group have lower platelet count and better EFS and OS. NOTCH1/FBXW7 gene mutation may be used as a hierarchical basis for individualized treatment of adult T-ALL patients.