'cancer-preventive' originates from a combination of English elements: the noun 'cancer' and the adjective 'preventive'. 'cancer' originates from Latin, specifically the word 'cancer' (from Greek 'karkinos'), where 'cancer' originally meant 'crab'. 'preventive' originates from Latin, specifically the verb 'praevenire', where the prefix 'prae-' meant 'before' and 'venire' meant 'to come (or arrive)'.

'cancer' passed into English via Old French/Latin (Latin 'cancer', from Greek 'karkinos'); 'preventive' entered English from Medieval Latin 'praeventivus' (from 'praevenire') through Old French/Anglo-Norman and Middle English. The modern compound 'cancer-preventive' was formed in modern English to denote agents or measures that prevent cancer.

Initially 'cancer' literally meant 'crab' and later became the name of the disease; 'preventive' has long meant 'acting to prevent'. Combined, 'cancer-preventive' originally described measures or agents intended to prevent cancer, and that core meaning has been retained in modern usage.