While exercise improved outcomes, cutting out meat and alcohol did not.
Patients at high-risk of breast cancer recurrence who adhere to lifestyle recommendations are 37% less likely to experience recurrence and 58% less likely to die from the disease than those who don’t, a new US study reveals.
“Education and implementation strategies to help patients adhere to cancer prevention recommendations throughout the cancer care continuum may be warranted,” the authors wrote in JAMA Network Open.
The findings provide some of the first data detailing the compounding influences of BMI, exercise, diet and smoking before, after and during chemotherapy.
The prospective cohort study of 1300 women with pathologic stage I to III high-risk breast cancer found those who maintained strict adherence to lifestyle recommendations had the longest periods of both overall and disease-free survival.
Researchers used a Lifestyle Index Score (LIS) to track adherence to recommendations from the American Institute for Cancer Research and American Cancer Society, before and after diagnosis, and up to two years post-treatment.
“In examining the role of individual lifestyles, strongest adherence to recommendations for smoking, physical activity, fruit and vegetable intake, and sugar-sweetened beverage consumption were associated with [the most] significant reductions in recurrence and mortality,” the authors wrote.
Never smoking and meeting the physical activity guidelines were among the most effective interventions, with strict adherence to either dropping the risk of death by 45% and the risk of recurrence by 35% compared to those who were least adherent.
Patients who were most adherent to fruit and vegetable intake advice benefited from a 31% reduction in death over the study period and 36% reduction in recurrence.
And avoiding sugar-sweetened drinks led to a 44% reduction in deaths and 27% reduction in recurrence.
However, there appeared to be no advantage for either mortality or cancer recurrence for people who were adherent to BMI, red and processed meat consumption or alcohol guidelines.
“[L]ifestyle interventions could be a safe, inexpensive, and feasible ancillary strategy for delaying and preventing recurrence and death from the most common cancer in the world. Such developments could be especially impactful for patients diagnosed with more aggressive tumours that do not respond well to current therapies,” the authors concluded.
Baseline characteristics such as age, menopause status, number of positive cancer nodes, hormone receptor status, tumour subtype, physical activity, smoking status, alcohol consumption and LIS, were significantly associated with mortality and disease outcomes.
Patients in the normal BMI range were classified as adherent, overweight patients were semi-adherent and obese/ underweight patients were classified as non-adherent.
In relation to alcohol consumption, individuals who abstained from drinking were categorised as fully adherent. Moderate adherence was defined as consuming one or fewer standard drinks per day. Consumption exceeding this limit was classified as non-compliant.
