The associations of obesity, lymph node status and prognosis in breast cancer patients: Dependence on estrogen and progesterone receptor status

Abstract

Breast cancer patients who are obese have a higher risk of lymph node metastases and a poorer prognosis than those who are slim. It has been claimed that estrogens derived from fat are important for these associations. If estrogens are important, these relationships must be stronger in the hormone receptor-positive than in the hormone receptor-negative groups. Body mass index (BMI) was used as a measure of obesity. The second, third, and fourth quintiles of BMI were treated as one group and termed 'medium'. Patients in the fifth quintile were termed 'obese' and those in the first quintile 'slim'. The number of women with unilateral disease treated with modified radical mastectomy and included in the study was 1211. Of all patients included, obese patients had a 1.53 higher risk of lymph node metastases compared to slim patients (p=0.02). In the PgR-negative group, obesity gave a 3.08 times higher risk of lymph node metastases (p=0.03). The risk of dying of breast cancer tended to be higher in obese than in slim patients when all patients in the study were compared (relative risk=1.38, p=0.06). BMI did not show a statistically significant relationship with prognosis if only hormone receptor status was considered. However, if lymph node status and hormone receptor status were taken together, the association was strong and reversed in the lymph node-positive group with ER-negative tumours. The adjusted relative risk was 0.33, showing that slim patients had a 3.03 (1.0/0.33) times higher risk of dying of breast cancer compared to obese patients (p=0.002). These results indicate that non-hormonal mechanisms could be important.

Is obesity an independent prognosis factor in woman breast cancer?

“…Obesity is well known as a risk factor for hormone-dependent tumors [51]. Moehle [52] and McNee [50] observed also a more accurate obesity effect among patients having positive tumors hormonal receptors while Moehle [32] and den Tonkelaar [34] did not confirm this finding. Adjusted obesity effect among subpopulations defined according to menopausal status suggests that independent obesity effect is more accurate among non-menopausal patient for metastasis recurrence (Table 4).…”

“…After univariate analysis, the obesity effect was adjusted with other main breast cancer prognosis factors [30,31] to examine a possible independent effect. Interactions suggested in literature data between obesity on one side and breast cancer extension indicators (local tumor extension and nodal involvement), hormonal and tumor receptors status on another side were investigated [19,[32][33][34]. The aim of this study is to give a consistent answer to the rising and still controversial issue regarding the prognosis role of obesity in breast cancer.…”

Effects of dietary fat on spontaneous metastasis of Lewis lung carcinoma in mice

“…Obesity has been identified as a significant risk factor for many types of cancer [4,5], and it has been associated with the poor prognosis and the poor disease outcome of cancer survivors [6,7]. For example, prostate cancer patients who are overweight or obese are more likely to have recurrence after radical prostatectomy than those men of normal weight [8,9], and breast cancer patients who are obese have a higher risk of lymph node metastasis than those who are slim [10][11][12][13].…”

Severe pulmonary metastasis in obese and diabetic mice

“…Maehle et al reported that breast cancer patients with obesity had a higher risk of lymph node metastases. 10 Although evidence has accumulated of an association of cancer with obesity, the influence of obesity and diabetes on cancer metastasis remains to be investigated. In addition, the mechanisms by which obesity promotes the development and progression of cancer are still unknown.…”