leukaemia vs cancer of the blood

leukaemia and cancer of the blood both are nouns.

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

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

leukaemia 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 leukaemia include leucaemia, leukemia.

leukaemia (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