In June 2018 researchers from Sweden published the results of their study to assess the role of coffee consumption on the prognosis of breast cancer and possible associations with tumor-specific insulin-like growth factor receptor 1 levels (which contribute to breast cancer growth) and body mass index (BMI). The researchers stated that whilst coffee is associated with a reduced risk of breast cancer, the role of BMI in combination with coffee consumption on prognosis is unclear. A total of 1,014 breast cancer patients were involved in the study and followed up for a period of 13 years. Results showed that individuals with a higher coffee consumption had lower tumor insulin-like growth factor receptor 1 levels, but only amongst those with a normal weight. Although coffee did not appear to influence the overall risk of recurrence, those with oestrogen receptor breast cancer who had been treated with tamoxifen appeared to have a lower risk of recurrence if they drank more than 2 cups of coffee/day when compared with individuals with a lower consumption but only if they were of normal weight. In addition, drinking more than 2 cups of coffee/day was associated with a significantly lower risk of recurrence in individuals who had been treated with radiotherapy but only if they were not overweight or obese. The researchers concluded by stating that a higher coffee consumption was associated with reduced tumour-specific insulin-like growth factor receptor 1 levels as well as an improved prognosis amongst tamoxifen- or radiotherapy-treated individuals with breast cancer but only if they were not overweight or obese.
Björner S et al. Coffee Is Associated With Lower Breast Tumor Insulin-Like Growth Factor Receptor 1 Levels in Normal-Weight Patients and Improved Prognosis Following Tamoxifen or Radiotherapy Treatment. Front Endocrinol (Lausanne). 2018 Jun 6;9:306.