The firm said that the decline was due to a customer shifting to internalizing genetic ordering, adverse weather, and the loss of an undisclosed commercial payor.
The revenue increase was driven in part by surging direct sales of the firm's diagnostic test cartridges and instruments in Europe, the Middle East, and Asia.
The company had to halt and later restart billing for its cancer risk assessment tests as it transitioned to a new billing process.
Excluding the impact of a one-time conversion from cash-based to accrual-based revenue recognition in 2017, year-over-year revenues were essentially flat.
As the firm continues to move toward commercialization of its test, its loss dropped to $3.8 million, or $.12 per share, from $4.7 million, $.16 per share, in the same period last year.
The UK-based noninvasive prenatal testing firm also said that it has raised £2.5 million in funding through a share subscription.
The increase was drive by revenue growth in Cancer Genetics' discovery services unit, which included the impact of recently acquired CRO VivoPharm.
The company beat the analysts' average estimate on the top line but missed it on the bottom line as it posted a net loss of $3.2 million.
Product revenues were $613,000, down from $678,000 in Q1 2017, while service revenues were $36,000, down from $48,000 the year before.
Amid reporting a loss of about $2.0 million for the quarter, Celcuity also said that it had completed the development of its second test, for breast cancer, based on the CELx platform.