Gene Test May Help Predict Colon Cancer's Return

TUESDAY, Feb. 17 (HealthDay News) -- A genetic test may better help survivors of colorectal cancer determine their risk of recurrence, a new study finds.

A report in the Feb. 18 issue of the Journal of the American Medical Association finds that guanylyl cyclase C (GUCY2C) -- an intestinal tumor-suppressing receptor in the lymph nodes -- may better reveal the chance of metastatic colorectal cancer.

According to researchers from Thomas Jefferson University in Philadelphia, doctors often biopsy the lymph nodes when trying to determine the prognosis of colorectal cancer. But when no cancer cells are found (a condition called pN0 colorectal cancer), the chance of recurrence is still about one in four. If cancer cells are found in four or more lymph nodes, the recurrence odds jump to one in two.

In studying 257 people with pN0 colorectal cancer, the team found that GUCY2C analysis "appeared to be an independent prognostic marker of risk." While conventional molecular staging techniques found 13 percent of patients were free of tumor cells, GUCY2C results suggested malignancy in 87 percent of cases.

Improved molecular staging "could overcome limitations in the detection of occult lymph node metastases," wrote the researchers.

The authors called for more studies with larger patient pools to better access the accuracy and reliably of the genetic test.