How does obesity affect survival in patients with multiple myeloma?

Obesity does not seem to have any significant impact on clinical outcomes, particularly survival, in patients with multiple myeloma (MM), according to a study presented at EHA 2023. However, obese MM patients aged <65 years tend to have a shorter overall survival (OS) than those with normal weight.

“Obesity is a risk factor for multiple myeloma (MM), as increased incidence and mortality were observed in obese MM patients,” said the researchers, led by Liang Ren, Department of Hematology, Zhongshan Hospital, Fudan University, Shanghai, China. “However, we are still [lacking] knowledge of the clinical course of obese MM patients in a broad view.”

Ren and colleagues reviewed patient records to assess the impact of obesity in MM and divided the participants into normal and obese group based on body mass index (BMI) at diagnosis (normal BMI, 18.5 to <25 kg/m²; obese, ≥30 kg/m²). In addition, they evaluated the baseline characteristics, cytogenetic abnormalities, treatment variability, and survival outcomes in the obese cohort.

A total of 568 patients with MM met the eligibility criteria, of whom 254 had normal BMI and 314 had obesity. The median follow-up time was 70.5 months (range, 1.5‒98.7). EHA 2023, abstract PB2148]

No differences were observed in baseline characteristics between normal and obese patients with MM, except for having more male patients in the obese group (59.9 percent vs 50.4 percent; p=0.024). Likewise, the overall distribution of cytogenetic abnormalities showed no specific favour between the two groups.

On the other hand, obese MM patients demonstrated a higher objective response rate (ORR) than did those with normal BMI (92.7 percent vs 88.6 percent; p=0.037). In addition, MM patients with obesity tended to need a shorter time or less cycles to achieve best response with first-line therapy.

“The presence of obesity might make patients benefit more from present therapy as obese MM patients had higher ORR and responded faster,” the researchers said.

Notably, progression-free survival was comparable between the normal and obese groups (p=0.88), while the median overall survival (OS) was shorter for MM patients with obesity, albeit not statistically significant (82.3 vs 95.3 months; p=0.25). However, subgroup analysis revealed that obese MM patients aged <65 years had significantly poorer OS than those with normal weight (p=0.047).

In a recent study examining the epidemiological data on obesity and MM, the investigators found significant effects of obesity on MM outcomes. In particular, higher BMI correlated with reduced survival in patients with MM. [Semin Cancer Biol 2023;92:45-60]

“Interestingly, the obesity paradox may also apply to patients with relapsed/refractory MM who are overweight or obese, because they may have a survival advantage,” according to the investigators.

“The pathophysiological pathways linking obesity to MM are very complicated and include bone marrow adipose tissue; adipokines, such as adiponectin, leptin, resistin, and visfatin; inflammatory cytokines and growth factors, such as tumour necrosis factor-α and interleukin-6; hormones including insulin and the insulin-like growth factor system, as well as sex hormones,” they added.