Apple tree canker

Have red devil apple tree and I see half way up branch looks like canker is it canker should I prune half the branch off to get rid of it our is it ok is half way round the branch but buds still look alive above it , what is it what should I do ,, thanks

 

I'm not sure what it is, but I'd get rid of it.

 

I believe that it is canker. I draw your attention to the advice of the RHS:
Apple canker / RHS Gardening
If this is high up in the tree, consider pruning below it and seal as they recommend. If not desirable/ possible, then trim back all brown tissue with a sharp knife to reveal green , living, tissue and aim to allow to heal bark. Do not go deeper than the 'halfway point', ideally not more than 1/3 of diameter. Remove all chippings from site(infectious)
No fungicides are approved for home use but I would attempt a 'winter wash' with Jeyes Fluid diluted.

 

From the Gardener's World site:
"
Use secateurs to cut out all infected growth. Infected branches show dark staining of the creamy coloured wood inside, so prune back to healthy wood that shows no sign of staining. Carefully slice away cankers on large branches and trunks using a sharp knife. Afterwards, sterilise your knife and secateurs with methylated spirits to avoid cross-contamination. "