Association of Locoregional Control With High Body Mass Index in Women Undergoing Breast Conservation Therapy for Early-Stage Breast Cancer

Abstract

Purpose Obesity, as measured by body mass index (BMI), is a risk factor for distant recurrence and decreased survival in breast cancer. We sought to determine whether BMI correlated with local recurrence and reduced survival in a cohort of predominantly obese women treated with breast conservation therapy. Methods and Materials From 1998–2010, 154 women with early stage invasive breast cancer and 39 patients with ductal carcinoma in situ (DCIS) underwent prone whole breast irradiation. Cox proportional hazards regression, Kaplan-Meier methods with log-rank test, and multivariate analysis were used to explore the association of outcomes with BMI. Results The median patient age was 60 years, and the median follow-up was 73 months. The median BMI was 33.2 kg/m2; 91% of patients were overweight (BMI≥25 kg/m2) and 69% of patients were clinically obese (BMI≥30 kg/m2). BMI was significantly associated with local-regional recurrence-free interval for invasive and DCIS patients (hazard ratio 1.09, p=0.047), and there was a trend for increased local-regional recurrence with higher BMI (p=0.09) for patients with invasive disease, which was significant when examining BMI above and below the median value of 33.2 (p=0.008). BMI was also significantly associated with decreased distant recurrence-free interval (DRFI; HR 1.09, p=0.011) and overall survival (OS; HR 1.09, p=0.004); this association remained on multivariate analysis (DRFI, p=0.034; overall survival, p=0.0007). Conclusions These data suggest that BMI may impact the rate of local-regional recurrence in breast cancer patients. Higher BMI predicted worse distant recurrence-free interval and overall survival. This investigation adds to growing evidence that BMI is an important prognostic factor in early stage breast cancer treated with breast conservation therapy.

Obesity as an independent predictive factor for pathologic complete response after neoadjuvant chemoradiation in rectal cancer

“…The association between obesity and cancer recurrence has been widely investigated in breast cancer, and was shown to be associated with local recurrence, distant metastasis, and decreased overall survival [202122]. One possible reason for these findings is that increased adipose tissue may elevate the levels of circulating estrogens, insulin, and insulin-like growth factors, which can facilitate cancer cell growth [22].…”

“…The association between obesity and cancer recurrence has been widely investigated in breast cancer, and was shown to be associated with local recurrence, distant metastasis, and decreased overall survival [202122]. One possible reason for these findings is that increased adipose tissue may elevate the levels of circulating estrogens, insulin, and insulin-like growth factors, which can facilitate cancer cell growth [22]. In contrast, some studies have reported that obesity was associated with better prognosis after chemoradiation in other types of cancers, such as cervical cancer, lymphoma, and head and neck cancers [2324252627].…”

The Impact of Obesity on Breast Cancer Diagnosis and Treatment

“…Following BCS, patients receive radiation therapy to the breast and, depending on their stage, may receive regional nodal radiation as well. While some series identify comparable local control rates in obese and normal-weight women undergoing lumpectomy and radiation therapy, others suggest that local recurrence is significantly higher in obese patients [ 18 , 19 •, 20 ]. What is clearer is that the cosmetic outcome with breast conservation (lumpectomy and radiation) may not be as good in obese women compared to normal-weight women.…”

Impact of obesity on breast cancer recurrence and minimal residual disease

“…Hence, most deaths resulting from breast cancer are due to an inability to effectively prevent tumor recurrence [10]. Similarly to epidemiological data linking obesity with increased primary breast cancer risk, obesity is also associated with a greater risk of breast cancer recurrence [11–16] (HRs ranging from 1.17 to 1.46 [13–15]), as well as a 30–40% increased risk of breast cancer-related death [11, 15, 17, 18]. Because the prevalence of obesity among U.S. women is > 40% [19] and may be even higher among breast cancer survivors [20], understanding the biological underpinnings of the association between obesity and recurrence risk is a critical unmet need.…”