Footnotes

• Contributors MS, DE and A-MM directed the study design, data acquisition and obtained funding. NC was responsible for data management and analysis, and all authors contributed to interpretation of the results. All authors were involved in manuscript preparation and read and approved the final manuscript.

• Funding This work was supported by a grant from Cancer Research UK (grant number: C24178/A22568).

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.