The decrease came as improved performance by its biopharma services operations was more than offset by declines in clinical and discovery services revenues.
The company also reported a decline in its net loss for the quarter on lower operating expenses due to a recent reorganization that included layoffs.
The company also reported a jump in its first quarter net loss as operating expenses climbed on higher research and development spending.
Revenues for the quarter were driven by a 27 percent rise in sales volume for the company's OVA1 test.
The firm is conducting validation studies on its lung cancer test and continues to anticipate commercializing it in the second half of this year.
The firm said its growth was driven in part by increasing sales volumes of its gastrointestinal PancraGen business and endocrine ThyGeNext/ThyraMir business.
The embattled company saw its net loss narrow during the first quarter, in part due to a new policy of giving away fewer nonreimbursed GPS Cancer and Liquid GPA molecular test orders than in the past.
The liquid biopsy firm beat analyst estimates on the top and bottom lines and raised full-year revenue guidance to $145 to $150 million.
The company's first quarter revenues were driven by sales of its noninvasive prenatal screening and carrier screening tests.
While the company's product and product-related revenues rose 54 percent, its collaborative development program revenues fell 78 percent.