{'fraction_non_alphanumeric': 0.038657171922685654, 'fraction_numerical': 0.038657171922685654, 'mean_word_length': 4.556497175141243, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Statin use and the development of bone metastasis in breast cancer patients.

40 Background: The Mevalonic Acid Pathway has been implicated in the promotion of a microenvironment suitable for establishment of bony metastasis from breast cancer. The statins, which act on this pathway, have been shown to have in vitro antineoplastic activity against breast cancer. This study was designed to evaluate the association of statin use and development of bony metastasis in breast cancer patients.


METHODS
Medical records of patients treated for stage II-III breast cancer from 1999 to 2010 were retrospectively reviewed. Statin use was defined as medication use for at least 3 months in patients with no evidence of disease after initial diagnosis and treatment. The primary outcome was development of metastasis to bone. Secondary outcomes were overall survival, disease free survival and other sites of distant metastasis.


RESULTS
A total of 841 patients were included in the study of which 223 used statins. Both unadjusted and multivariate analysis adjusted for age, race, grade, stage, BRCA status, showed that patients on statins had a significantly lower incidence of metastasis to bone (OR 0.49, 95% CI 0.25-0.96, p=0.04). Adjusted analysis for other sites showed a trend towards decreased incidence of metastasis for statin users, but was not statistically significant (95% CI 0.39-1.08, p=0.10). Overall survival was increased in statin users with mean survival of 66.45 +/- 2.48 months versus non-users 58.78 +/ - 1.41 months (p=0.05). Statin users had significantly longer disease free survival with a mean of 63.65 +/- 2.49 months versus 53.96 +/- 1.42 months in non statin users (p=0.00).


CONCLUSIONS
The use of statin drugs in patients with breast cancer was significantly associated with decreased incidence of metastasis to bone, but not to other distant sites. The role of statins in chemoprevention of bone metastasis should be further explored.