leucaemia vs cancer of the blood

leucaemia and cancer of the blood both are nouns.

Word	Noun	Adjective	Verb	Adverb
leucaemia	Yes	No	No	No
cancer of the blood	Yes	No	No	No

As nouns, leucaemia and cancer of the blood are synonyms defined as:

leucaemia and cancer of the blood: malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancer

Other synonyms of leucaemia include leukaemia, leukemia.

leucaemia (noun)	cancer of the blood (noun)
malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancer	malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancer