HMG co-reductase expression and response to intravesical Bacillus Calmette-Guérin in patients with high grade non-muscle invasive urinary bladder cancer receiving statins.

Background: Cardiovascular disease affects over 7 million people in the UK and statins are often prescribed to mitigate cardiovascular risks. The effect of statins on a number of cancers is debated and their effect on Bacillus Calmette-Guérin (BCG) responsiveness in non-muscle invasive urinary bladder cancer (NMIBC) is not fully understood.

Aims: This study aims to explore the difference in HMG Co-A reductase (HMGCR) expression in NMIBC on immunochemistry in BCG responders and non-responders while on statins.

Method: Three hundred and thirty-two cases of intravesical BCG treatment for high-risk NMIBC between November 2003 and December 2017 were identified. Patients taking statins for at least 12 months before the diagnosis of NIMBC and with a follow-up of at least 5 years were included. They were divided into BCG responders and non-responders. Tumour tissue from these patients was immunohistochemically stained and quantitative image analysis carried out to assess and compare HMGCR expression in the groups.

Results & conclusion: This study showed a differential expression of HMGCR in responders vs. non-responders to BCG for high-risk NMIBC on statins. This data should form the basis of a further research and multi-centre study in a larger cohort, using HMGCR as a biomarker of response in patients on statins.