Freund's vaccine adjuvant promotes Her2/Neu breast cancer

The effects of FA on hyperplastic mammary lesions and mammary carcinomas were determined in a neu-induced rat model. The inflammatory response to FA treatment was gauged by measuring acute phase serum haptoglobin. In addition, changes in cell proliferation and apoptosis following FA treatment were assessed.Rats receiving FA developed twice the number of mammary carcinomas as controls. Systemic inflammation following FA treatment is chronic, as shown by a doubling of the levels of the serum biomarker, haptoglobin, 15 days following initial treatment. We also show that this systemic inflammation is associated with the increased growth of hyperplastic mammary lesions. This increased growth results from a higher rate of cellular proliferation in the absence of changes in apoptosis.Our data suggests that systemic inflammation induced by Freund's adjuvant (FA) promotes mammary carcinogenesis. It will be important to determine whether adjuvants currently used in human vaccines also promote breast cancer.The etiology of breast cancer involves the interaction of inherited risk with environmental exposure. Approximately 30% of breast cancer risk is inherited [1], the majority of which is controlled by modifier genetic elements individually having low genetic penetrance, but high population frequencies [2]. Our knowledge of environmental factors that modulate breast cancer risk is quite incomplete. The best documented association is for ionizing radiation, which carries the highest risk for breast cancer when exposure occurs prior to adulthood [3]. Other known promoters of breast cancer include exogenously administered hormonal replacement therapies [4].Chronic inflammation arising from a variety of environmental and infectious sources is associated with promotion of many cancer types [5]. Evidence for chronic inflammation in breast cancer etiology is supported by experimental [6] and epidemiological studies suggesting that anti-inflammatory drugs can help prevent breast cance