Switching to a higher-quality diet and quitting smoking may improve survival for patients diagnosed with multiple myeloma, an Australian study suggests.
Melbourne epidemiologists surveyed 760 patients newly diagnosed with multiple myeloma (MM) between 2010 and 2016, who had been recruited to the study via cancer registries in NSW and Victoria, about modifiable health and lifestyle factors.
Participants (median age 64, 58% male) had histologically confirmed multiple myeloma or plasmacytoma and were aged 20-74 at diagnosis.
The researchers assessed diet using the Alternative Healthy Eating Index (AHEI), which assigns higher scores to fruit, vegetable, nuts, polyunsaturated fatty acid and long-chain omega-3 and lower scores to sugar, sodium and processed meats.
During follow-up, 261 cases died of any cause and 153 from MM-related causes.
Findings published in Expert Review of Hematology [link here] showed that higher pre-diagnosis AHEI scores were associated with reduced MM-specific fatality, with an estimated 16% reduced risk of death due to MM per 10-unit score (HR 0.84).
Former and current smokers had a 31-64% increased risk of MM-specific fatality compared with never-smokers, while ever-smokers had a 37% increased risk.
Smoking was also associated with increased all-cause fatality compared with non-smoking (ever smoking 41%; former smoking 44%; current smoking 30%).
However, there was no association between pack-year smoking history and MM-specific or all-cause fatality, noted the researchers, led by the Cancer Epidemiology Division of Cancer Council Victoria and the University of Melbourne.
Interestingly, there was an inverse association between pre-diagnosis alcohol consumption and MM-specific fatality compared with non-drinkers (0.1-20g of ethanol per day, HR=0.59; >20g per day, HR=0.67), although the researchers noted they were unable to separate recent former drinkers from long-term abstainers.
They said it was possible some lifelong drinkers who stopped consuming alcohol as a consequence of preclinical disease were included in the non-drinking group.
As for BMI, a higher score at enrollment was associated with reduced risk of MM-specific fatality, but this inverse association was not apparent for pre-enrollment when the researchers accounted for weight change in the preceding five years.
They said this finding might be explained by disease-related weight loss, which was often an indicator of more aggressive disease onset and poor prognosis.
“In our study of a large cohort of predominantly registry-recruited cases diagnosed with multiple myeloma in Australia, we found an inverse association with MM-specific fatality for healthier diets prior to diagnosis as measured by the AHEI score, and for pre-diagnostic alcohol consumption,” the authors said.
“As multiple myeloma survival extends and prevalence grows, the importance of lifestyle changes may increase as a way for MM patients to take an active role in care in partnership with clinicians. Healthy lifestyle changes could potentially introduce additional benefits to quality of life.”
The authors noted that the younger age and relatively less severe disease of the cohort might have impeded the ability to detect some associations between exposures and all-cause fatality and also impacted generalisability of the findings.