HER2 and genomic testing for biliary cancer on the NHS

Gallbladder cancer carries HER2 amplification more often than other biliary cancers (about one in six in the site's record), and zanidatamab was approved by the MHRA in February 2026 for HER2-positive biliary tract cancer after chemotherapy, with a NICE appraisal under way. Mismatch repair deficiency, BRAF V600E and NTRK fusions open tumour-agnostic options, so the NCCN guideline asks for molecular profiling of all advanced biliary cancers. AMMF's molecular profiling booklet explains that "a small sample of tumour or blood is tested to see if there are gene mutations or rearrangements which 'drive' the cancer" and that "if there are, then there may be a targeted treatment option".

On the NHS, testing is requested by the specialist: the NHS page says "you need to be referred for genetic testing by a doctor. Talk to your hospital specialist about whether testing is right for you", and for cancer "the test will be done on a sample of the tumour that has already been removed as part of your treatment", through the NHS Genomic Medicine Service. Questions worth asking: whether HER2 has been tested by immunohistochemistry and in situ hybridisation, whether a gene panel has been sent and how long it takes, whether there is enough tissue or a fresh biopsy is needed, and whether the results would change the treatment you are offered. This is orientation from public patient pages, not advice for your case: your own team's instructions and 24-hour number come first.