Oral sex does not directly cause throat cancer, but it can spread HPV. HPV can cause pre-cancerous changes in cells that may lead to throat cancer later on. Smoking and alcohol consumption further increase the risk that an HPV infection will become cancerous.
From medical news today.
I also didn't realise there was a vaccine for HPV, something to research. Had a quick look CDC in the states reccomend best stage if effectiveness at 12-13. Can be given up to 45 years old but you would need to speak to a doctor about its effectiveness.