Associations between circulating obesity-related biomarkers and prognosis in female breast cancer survivors: a systematic review of observational data in women enrolled in lifestyle intervention trials

Abstract

Obesity plays an important role in the development and progression of breast cancer via various oncogenic pathways. However, the biological mechanisms underlying this relationship are not fully understood. Moreover, it is unclear whether obesity-related and further associated biomarkers could be suitable targets for lifestyle interventions. This systematic review was conducted to examine relationships between obesity-related blood parameters and prognosis for breast cancer survivors enrolled in lifestyle intervention studies. A systematic, computerized literature search was conducted from inception through August 26th, 2020 in PubMed, EMBASE, and CENTRAL. The focus was on observational data from randomized controlled lifestyle intervention trials investigating associations between selected baseline biomarkers, measured in remission, and breast cancer recurrence, breast cancer mortality and/or all-cause mortality. Four studies with data from 5234 women met the inclusion criteria.Studies herein provide moderate evidence that bioavailable or serum testosterone may be positively linked to breast cancer recurrence and inversely linked to disease-free survival. Limited evidence suggests no associations with circulating estradiol or insulin levels on prognosis outcomes, whereas HDL cholesterol was inversely associated with breast cancer recurrence. For some other biomarkers, such as growth factors, adipokines, and CRP, the evidence for associations with disease prognosis was too weak to draw conclusions.Overall, despite potential candidates, there is insufficient evidence to confirm or refute that obesity-related biomarkers and sex hormones have a prognostic value for breast cancer survival. More longitudinal studies in breast cancer survivors to examine the clinical utility of obesity-related biomarkers are needed.

Association between dietary inflammatory index and body fat percentage among newly diagnosed breast cancer patients

“…Growing evidence suggests that there is a mutual bidirectional association between body fat and inflammation [ 41 ]. Although adiposity promotes the production of inflammatory cytokines, a pro-inflammatory diet can sustain and increase body fat, thereby producing a vicious cycle [ 9 , 20 ]. Our study supports this theory as significantly higher white blood cell and lymphocyte counts across the E-DII tertiles might reflect the ongoing subtle chronic inflammation effect from such a pro-inflammatory diet although the exact mechanism between DII and body fat remains uncertain, it was found that a more pro-inflammatory diet was associated with higher leptin and a lower adiponectin to leptin ratio [ 42 ], and there is a direct association between leptin levels and fat mass in obese individuals.…”

“…Low-grade chronic inflammation is a hallmark of obesity [ 8 ]. Excess adipose tissue fosters a chronic systemic inflammatory microenvironment by producing a multitude of cytokines and acute-phase proteins such as interleukin-6 and C-reactive protein, which activate pro-inflammatory signalling pathways and prompt tumour development and progression [ 9 ]. Obesity is also linked to white adipose tissue breast inflammation capable of activating the nuclear factor kappa B pathway and the production of oestrogens by the enzyme aromatase, contributing to tumour development and progression [ 10 , 11 ].…”

An Integrated Care Approach to Improve Well-Being in Breast Cancer Patients

“…Indeed, lifestyle improvement has a significant impact on BC management after initial diagnosis, both in term of therapeutical efficacy and QoL [ 33 ]. Despite the overall nutritional healthy choices, the maintenance of a normal body weight is mandatory, since it is well documented that obesity is linked to worst outcomes [ 34 , 35 ]. For these reasons, particular attention must be paid to meeting the protein and caloric needs as part of managing weight and body composition, as mentioned before, a crucial aspect of BC treatment.…”