My dad has diagnosed with COPD 5 years ago ,but was quite up beat and got on . Last January (2019) he had a severe chest infection and was given 2 antibiotics, these did nt seem to work ,his breathing got worse ,eventually he drove himself to A & E one night and was admitted, after tests he was diagnosed with stage 4 inoperable lung cancer(7cm tumour  )and died within a month , it has always bothered me that the cancer was mis diagnosed  as copd ,and if caught earlier could of been treated ,is this possibly a mis diagnosis ?