breast cancer vs carcinoma

breast cancer and carcinoma both are nouns.

Word	Noun	Adjective	Verb	Adverb
breast cancer	Yes	No	No	No
carcinoma	Yes	No	No	No

As nouns, carcinoma is a hypernym of breast cancer; that is, carcinoma is a word with a broader meaning than breast cancer:

breast cancer: cancer of the breast; one of the most common malignancies in women in the US
carcinoma: any malignant tumor derived from epithelial tissue; one of the four major types of cancer

breast cancer (noun)	carcinoma (noun)
cancer of the breast; one of the most common malignancies in women in the US	any malignant tumor derived from epithelial tissue; one of the four major types of cancer