Patients who delay receiving diagnostic tests such as a CT scan after receiving a positive screening study have an increased risk of cancer, late-stage cancer, and mortality, according to a large-scale literature review published online March 30 in CA: A Cancer Journal for Clinicians.
An interdisciplinary team of researchers from the Population-Based Research Optimizing Screening Through Personalized Regimens Consortium arrived at their findings after reviewing breast, cervical, colorectal, and lung cancer studies in the literature between January 1998 and December 2017. Although the conclusions follow the longstanding conventional wisdom, the study backed up this message with patient outcome data, according to the group led by Dr. Chyke Doubeni from the University of Pennsylvania Perelman School of Medicine.
The researchers noted that patients each have different cancer trajectories, and there is no established time frame that is OK to wait before having a diagnostic test without risking cancer progression.
"To ignore these findings is not patient-centered," Doubeni said in a statement. "The longer a patient waits, the less likely they are to get the diagnostic testing done. There is also the risk that precancerous or early tumors will become more advanced cancers that are more difficult or impossible to cure."
The researchers offered suggested targets ranging from 60 to 90 days by when diagnostic testing should be performed for each of the four cancers. They were not able, however, to ascribe a certain number of risk points based on exactly how long a patient waits to receive a diagnostic test. While cervical cancer, for example, takes longer on average to progress than lung cancer, the authors cautioned against saying that it's safe to wait a little longer if you have cervical cancer versus another cancer.
In future work, the researchers hope to identify the appropriate data to identify time intervals that are potentially safe to wait before undergoing diagnostic testing.