Under terms of the deal, Genomic Health stockholders will receive $27.50 in cash and $44.50 in Exact Sciences stock, for a total value of $72 per share.
Wisconsin-based Exact Sciences makes non-invasive fecal DNA screening test Cologuard to help diagnose colorectal cancer.
Genomic Health develops and commercializes genomic-based diagnostics tests using its Oncotype IQ platform for various cancers, including breast and prostate.
The deal, expected to close by end-2019, is estimated to yield about $25 million in cost synergies within the third year, the companies said in a statement.
Shares of California-based Genomic Health rose 10.7% to $76.01 in early trading, while Exact Sciences' shares fell 3.3% to $114