Yes, CANCERS is a Scrabble word!

Letter values in Scrabble US: C 3, A 1, N 1, C 3, E 1, R 1, S 1.

Is it a valid word?

CANCERS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any malignant growth or tumor caused by abnormal and uncontrolled cell division; it may spread to other parts of the body through the lymphatic system or the blood stream
(astrology) a person who is born while the sun is in Cancer
a small zodiacal constellation in the northern hemisphere; between Leo and Gemini
the fourth sign of the zodiac; the sun is in this sign from about June 21 to July 22
type genus of the family Cancridae

Also: malignant neoplastic disease, cancer the crab, genus cancer.