Obesity Likely to Adversely Affect Survival Among Patients With ALL

Higher mortality rates were seen among patients with acute lymphoblastic leukemia (ALL) who were considered obese, in a recent study of patients treated at Mayo Clinic, according to findings published in Blood and Lymphatic Cancer: Targets and Therapy.

A subanalysis from the study also shows that this risk is even more apparent among the patients who have T-cell ALL who are considered obese, per World Health Organization body mass index classification (BMI, > 30 kg/m2). Obesity’s effects on heart disease and cancer are well known, the investigators stated, but outcomes are less established among adult patients with ALL.

“Current risk classification strategies are based primarily on age as well as the analysis of genetic abnormalities of leukemic blasts and careful monitoring of each patient’s response to therapy,” they stated. “However, certain clinical features, such as obesity, which are not typically used for risk stratification, are also associated with outcomes of acute leukemia.”

Results of the retrospective cohort study show an overall mortality rate among patients with ALL classified as obese that is more than 1.5 times that of nonobese patients (HR, 1.60; 95% CI, 1.03-2.50; P = .035). That for the patients with T-cell disease was more that 3 times that rate (HR, 5.42; 95% CI, 1.84-15.98; P < .001).

Event-free survival (EFS) was also 2.5 (95% CI, 1.00-6.21; P = .042) times lower in the obese patients, who were more likely to be women (P = .024) and at least 60 years old (P < .003).with

For this group of 154 consecutive patients (median age, 42.5 [range, 18-82] years; median BMI, 27.9 kg/m2 [overweight classification]) with ALL diagnosed between 1994 and 2011 who received treatment at Mayo Clinic in Rochester, Minnesota, the primary outcome was 5-year mortality. Most (55.2%) presented with an ECOG performance score of 1.

Similar outcomes were not seen in the patients with B-cell lymphoma who were considered obese (n = 44) or not obese (n = 76), nor were EFS or relapse rate discrepencies found among these patients overall, during a median follow-up of 8.37 years.

Analyses also determined the following:

• The obese patients were the oldest, followed by the overweight and normal weight (BMI, 18.5 to 25 kg/m2) patients (P = .002)
• No significant mortality differences were seen between the normal and overweight patients
• More nonobese patients (49%) vs obese patients (28%) received a blood or bone marrow transplant, and their median time from diagnosis to transplant was 22% shorter: 5.8 (range, 2-162) vs 7.4 (range, 2-46) months
• Fifty-two patients died as a result of disease relapse, 27 from posttransplant complications, and 10 from undetermined causes.

The authors note that their findings conflict with those of similar studies conducted among children and adults. Mortality differences for overall survival, EFS, and relapse were not seen among 4 groups of children from St. Jude Children’s Research Hospital who were classified as underweight (BMI, ≤ 10th percentile), normal weight (BMI, 10th-85th percentile), at risk of overweight (BMI, 85th-95th percentile), or overweight (BMI, > 95th percentile). And 2 other studies performed among adults did not find a link between obesity and decreased survival or increased toxicities.

An important area for future study is plasma leptin level and its varying effects on T- and B-lymphoblastic cells. This hormone has a potential role in leukemia pathophysiology, as evidenced by current studies showing a significant positive correlation with blast cell percentage. Another area to focus on is how obesity affect the pharmacokinetic and pharmacodynamics of chemotherapy drugs. Data are limited in both areas, the authors noted.

Reference

Liu Q, Major B, Le-Rademacher J, et al. The impact of obesity on the outcomes of adult patients with acute lymphoblastic leukemia—a single center retrospective study. Blood Lymphat Cancer. 2021;11:1-9. doi:10.2147/BLCTT.S269748