The application of improved chemotherapy regimens and novel chemotherapy for acute lymphoblastic leukemia (ALL) has increased the complete remission rate to 85%-90%, however, secondary ALL is common, and the prolonged long-term survival rate is only 30%-50% among ALL patients.

Favorable outcomes decrease with increasing age, and overall survival is greater for adult patients with de novo ALL, compared with patients with secondary ALL, according to the Jiansheng Zhong of the department of hematology, Guangzhou Red Cross Hospital, Jinan University, Guangzhou, Guangdong, China, and colleagues in a new study published online in Clinical Lymphoma, Myeloma & Leukemia.

The researchers retrospectively analyzed the results of 8,305 ALL patients undergoing chemotherapy from the Surveillance, Epidemiology, and End Results (SEER) database during 1975 to 2015, of which 7,454 (80.1%) cases were in the de novo ALL group, and 851 (19.9%) cases were in the secondary acute lymphoblastic leukemia (sALL) group. They used propensity matching before assessing overall survival between the two groups.

Demographically, the results showed that women ALL patients had a lower risk of death than men [hazard ratio (HR) = .93, P < .01], and that the mortality in blacks was higher than that of whites (HR = 1.29, P < .001).

For both ALL groups, patients aged 45-75 years and patients 75 years and older had a higher risk of death than younger patients (HR = 1.82, P < .001 and HR = 3.85, P < .001, respectively).

Although the mean age of de novo ALL group was significantly less than that of the sALL group (51.1 vs. 60.3 years, P < .001), after the propensity matching, the 1-, 2-, 3-, 4- and 5-year overall survival of the de novo ALL group was higher than that of the sALL group at all ages (18-75 years, P < .001).

The authors speculated that one reason for the across-the-board increased mortality in sALL, compared with de novo ALL, might be the fact that sALL patients have been reported to have more MLL gene rearrangements and chromosomal aberrations than are found in de novo ALL. This has previously been suggested as the reason for poor prognosis in secondary ALL patients.

One limitation of the study mentioned by the authors was the lack of individualized chemotherapy data available for analysis. “Considering that the features of sALL and chemotherapeutic modalities or therapy protocols may affect the mortality of sALL, more work is needed to be done in the future to demonstrate the association between chemotherapy and the prognosis of ALL patients, and the influence of cytogenetic lesions and molecular characteristics on sALL,” they concluded.

The authors declared they had no conflicts of interest.

SOURCE: Zhong J et al. Clin Lymphoma Myeloma Leuk. 2020 Apr 30; doi.org/10.1016/j.clml.2020.04.013.