C&Pd from a Google search…
Macmillan Cancer Support.
“Lung cancer may affect your ability to drive safely. If you hold a large goods vehicle (LGV) or a passenger carrying vehicle (PCV) driving licence, you’ll need to notify the DVLA (England, Scotland and Wales) or the DVA (Northern Ireland) if you have been treated for lung cancer in the last five years.”
But, as already pointed out, I’d be inclined to do this when things have calmed down.
Focus on getting better.
All the best.