Do Tumor Markers Mean Shannen Doherty's Breast Cancer Returned?

Premier Health Now

Although 47-year-old actress Shannen Doherty is understandably anxious after learning that some of her tumor markers were elevated after a recent blood test, it doesn’t necessarily mean her breast cancer has returned. Doherty, who is currently in remission, made the announcement via Instagram earlier this month. Tumor markers are substances found in blood that may be a sign of cancer. But because it’s normal to find some tumor markers during any routine blood test, their presence does not always indicate cancer.

Premier Health Now asked Mark Marinella, MD, oncologist at Premier Health and certified physician with MD Anderson Cancer Network®, to clarify the role that tumor markers play in cancer diagnosis. He explained that testing for tumor markers is useful when monitoring a patient with Stage 4 breast cancer. But the test has not been found to be useful for patients with Stage 1, 2 or 3 breast cancer who have completed treatment and have no symptoms that the cancer has returned.

“Once these patients have completed all their treatment, they sometimes ask to have their tumor markers checked to determine if the cancer is coming back,” he says. “They think that if it has returned, they want to know early.” But national guidelines discourage tumor marker tests for such patients as long as they have no symptoms. “In these cases, several studies have shown that if their tumor markers came back at high levels, further treatment would not improve outcomes,” Dr. Marinella explains. What’s more, the radiation from follow-up CT or PET scans could cause the patient additional harm. “We know that 1 to 2 percent of cancers might be due to the radiation from CT scans,” he adds.

Mark Marinella, MD

Mark Marinella, MD

View Profile View Articles