Context

• In a new study, researchers say it might be possible to detect some types of cancers through blood tests known as PanSeer.

Key Details

• Using PanSeer, a noninvasive blood test that is based on circulating tumor DNA methylation a total of 575 initially healthy samples who presented as asymptomatic were diagnosed with one of the five most common cancer types (stomach, esophagus, colorectum, lung or liver) within four years of blood draw.
• PanSeer was able to detect five common types of cancers in 95 per cent of asymptomatic individuals who were later diagnosed with cancer.

So, what can the test actually do?

• The PanSeer test is most likely to identify cancer in those individuals that already have cancerous growths but are asymptomatic to other diagnostic tests and screening methods.
• It cannot predict a patient who will develop cancer at a later stage if that individual does not already have a cancerous growth.
• The PanSeer test is also a first-line screening method, a patient who tests positive on it will have to subsequently undergo a reflex blood test or follow-up imaging so that their tissue of origin can be mapped, followed by a pathological examination to confirm the presence of cancer.
• Importantly, the test cannot detect the type of cancer.
• Using such blood tests cancers can be detected at early stages, which means treatments can be planned for earlier, given that cancer treatments are more successful when the disease is detected early on.

Back to basics

How is cancer typically diagnosed?

• Typically, cancers are detected when individuals present themselves with certain symptoms, post which a number of tests are used for diagnosis such as laboratory tests, tumor biopsies and diagnostic imaging among others.