A subgroup of lung cancers is characterized by the improper action of a protein called Epidermal Growth Factor Receptor (EGFR). These cancers are often referred to as EGFR-mutant lung cancers and are particularly common among never smokers and women. Drugs that block the action of EGFR (such as erlotinib) are available and have been shown to initially give good treatment responses in patients with EGFR-mutant lung cancer.
Unfortunately, most patients with EGFR-mutant lung cancer who receive erlotinib show disease progression after approximately one year of treatment due to the tumor cells becoming resistant to the drug.
Effective and safe strategies to achieve longer lasting disease control are urgently needed in order to improve the long-term outcome for these individuals. Dr. Pamela Hershberger’s lab recently made the novel discovery that vitamin D3 specifically blocks the growth of EGFR-mutant lung cancer cells. Based on other published scientific studies, they hypothesize that vitamin D3 may also make these particular lung cancer cells more sensitive to erlotinib and can delay or prevent erlotinib resistance.
Dr. Hershberger’s donor-funded study is designed to test this idea by determining how vitamin D3 influences the behavior of EGFR-mutant lung cancers, the extent to which vitamin D3 increases the anti-tumor activity of erlotinib, and whether evidence of vitamin D3 action is detectable in stored clinical specimens from patients with EGFR-mutant lung cancers. Because erlotinib is already approved as treatment of lung cancer and safe strategies to deliver vitamin D3 also exist, positive results from our studies can be rapidly developed into lung cancer clinical trials.