Exact Sciences, maker of the colon cancer test Cologuard, has signed a multimillion deal with drug giant Pfizer to increase and share in the costs of marketing the test — a move Wall Street cheered yesterday.

The bottom line: Physicians and other medical professionals should be ready for an onslaught of calls and face-to-face pitches from the companies' sales armies, even though there is evidence the costly Cologuard test can lead to false positives.

The big picture: This marketing blitz inevitably will push more people to get checked for colon cancer, which public health experts say is a good thing. Colon cancer is the second-leading cause of cancer death in the U.S.

But experts also say it will come at a steep price with potentially harmful and wasteful care.

• A doctor must prescribe Cologuard, an FDA-approved home kit where people mail their stool to a lab for DNA testing.
• Medicare pays $509 for Cologuard. Most other commercial health insurers cover it, and likely pay more than Medicare.
• The U.S. Preventive Services Task Force says Cologuard is acceptable for colon cancer screening. But when compared with cheaper tests, Cologuard was tied to "more false-positive results, more diagnostic colonoscopies, and more associated adverse events per screening test," and it "may potentially lead to overly intensive surveillance," according to the USPSTF.
• "Worried patients and/or providers may feel obligated to order additional tests — which could be imaging or invasive — to determine whether there could be a cancer elsewhere in the body, thus potentially adding to the costs and risks of Cologuard screening," Richard Hoffman, a professor of internal medicine and epidemiology at the University of Iowa, said in an email.
• An Exact Sciences spokesperson referred to a company-funded study on why it believes Cologuard is better than other tests.

By the numbers: The financial terms of the agreement are lucrative for both sides.

• Pfizer will spend nearly $70 million in Cologuard marketing and promotion from October through the end of 2021.
• Exact Sciences will maintain its baseline marketing spend of at least $80 million per year and match Pfizer's additional spending.
• Any profits that are earned over certain Cologuard revenue thresholds will be split 50-50, and Pfizer can get a royalty of up to 3% of Cologuard sales for three years after the deal ends in 2021.
• A Pfizer executive told investors it made the deal because it had a sales team for Lyrica, a drug that is losing market exclusivity, that could shift to Cologuard instead.
• Exact Sciences expects to bring in at least $1.2 billion in Cologuard revenue by 2021.
• CEO Kevin Conroy made almost $50 million over the past three years, including $32.3 million in 2017.