N24: Systematic Linkage Of All Diagnostic Hereditary Cancer Genotypes To The National Cancer Registry

F. McRonald1, B. Shand1, 2, N Bricault2, S. Vernon1, J. Rashbass1, 2, J. Burn3

1 – Public Health England. 2 – Health Data Insight CiC, Cambridge. 3 – Northern Genetics Service, Newcastle.


Aim: To create a national service collecting pseudonymised germline cancer-predisposing genotypes, and link these to the National Cancer Registration and Analysis Service for individuals with a prior or subsequent cancer diagnosis.

Method: NHS molecular genetics laboratories submit patient-level genotype data through a secure online portal. Unique patient demographics are pseudonymised using a one-way hash function that generates an irreversible pseudoID; additional identifiers are secondarily encrypted. The same hash function applied to cancer registration records, where patient identity is already known, enables linkage of the genotype data; decryption of additional identifiers is then possible. We can thus obtain accurate variant counts nationally, and identify those who develop cancer, without compromising patient privacy.

Results: Pilot work has focused upon BRCA1 and BRCA2 genes; we are now commencing collection of colorectal cancer predisposition gene data. To date, ten laboratories have submitted BRCA1/2 data, covering a time period from 2001 onwards, and including ~1300 different gene variants. Initial linkage to cancer registry records showed a 68% match rate.

Conclusion: This robust, secure system collects depersonalised but linkable genotypes on all individuals tested. Record-level linkage to the rich phenotype, treatment and outcome data in the national cancer registry provides allelic frequency and associated phenotype data, and facilitates variant interpretation.