Serum Selenium Levels Predict Breast Cancer Prognosis

Research done in southern Sweden shows that three blood biomarkers of selenium availability correlated inversely with mortality from breast cancer. The lower the three selenium biomarker levels, the higher the mortality [Demircan 2021].

Breast cancer pink ribbon
Assessment of selenium status at the time of breast cancer diagnosis identifies patients at exceptionally high risk for a poor prognosis. They are breast cancer patients with low levels of selenium, selenoprotein P, and glutathione peroxidase in their blood.

The blood biomarkers are:

  • Total selenium
  • Selenoprotein P
  • Glutathione peroxidase 3

Breast cancer patients with blood concentrations of these three selenium biomarkers in the highest quintile had significantly better chances of survival compared with patients whose blood levels of these substances were in the lowest quintile [Demircan 2021].

Breast cancer patients with low selenium status according to these three biomarkers had the highest mortality risk with an overall survival probability of approximately 50% after 8 years. The difference in survival between the breast cancer patients in the lowest selenium quintile compared to breast cancer patients with at least one biomarker in the highest quintile was especially notable [Demircan 2021]. read more

Selenium supplements and breast cancer

Studies show that selenium intake and status are associated with breast cancer risk.  Low selenium status indicates an increased risk of breast cancer.

In many countries, breast cancer is the most commonly diagnosed and treated form of cancer.  A 2014 meta-analysis of 16 studies has shown that there is a statistically significant association between serum selenium status and risk of breast cancer.  The lower the serum selenium concentration, the greater the risk of breast cancer [Babaknejad].

What do we know about selenium and breast cancer?
Breast cancer is a frustrating topic for the selenium researcher.  There is not enough evidence to permit definitive statements about the effects of selenium supplementation on the prevention of breast cancer.

For example, the Nutritional Prevention of Cancer (NPC) study – a study that showed significant associations between selenium supplementation and reduced risk of colorectal, lung, prostate, and total cancer – did not enroll enough women for the effect of selenium supplementation on breast cancer to be studied [Clark]. read more