Table 3.

Biological Process Relevant to Breast Cancer Etiology (table from Schwarzman et al., 2015).

Cellular & molecular events	Tissue changes	Susceptibility factors
Actions in hormone levels, metabolism, or receptors Cell cycle changes Changes in transcription, translation, and epigenetic programming of genes associated with breast cancer Altered activity or expression of peptide hormones (growth hormones) Immune modulation Inflammation Oxidative stress Genotoxicity Limitless replication potentiala Evasion of apoptosisa Autocrine growtha	Altered mammary gland development Terminal end bud proliferation Ductal hyperplasia Atypical hyperplasia Increased breast density/stromal hyperplasia Adenomas Carcinoma in situ Tissue invasiona Sustained/enhanced angiogenesisa	Early onset of puberty Increased lifetime duration of estrogen exposure (early menarche or late menopause) Alterations in cyclicity Atypical function of metabolizing enzymes Obesity

^aIndicators consistent with the hallmarks of cancer progression as defined by (Hanahan and Weinberg, 2011).