British spelling vs antitumour

British spelling is a noun but antitumour is not a noun.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
antitumour	No	Yes	No	No

British spelling (noun)	antitumour (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')

British spelling (adjective)	antitumour (adjective)
	used in the treatment of cancer