Nick Mulcahy

June 14, 2017

CHICAGO – Among women who have been treated for early-stage breast cancer and are under surveillance, more than a third (37%) receive what are very likely to be unneeded tumor-marker blood tests, according to new research from the state of Washington.

Nearly one fifth (17%) of the women also received likely superfluous advanced imaging, say the authors, led by Gary Lyman, MD, a breast cancer oncologist and a health economist at the Fred Hutchinson Cancer Research Center in Seattle.

The testing and imaging are extraneous because the women are under surveillance and are presumably asymptomatic. Thus, they derive little or no medical benefit from the interventions, said the study authors, who presented the study in a poster here at the American Society of Clinical Oncology (ASCO) 2017 Annual Meeting.

For such asymptomatic women, ASCO recommends against the routine use of advanced imaging and blood tests to track tumor markers.

The unnecessary interventions may result in harms, because false-positive results can lead to unnecessary procedures, unneeded radiation exposure, misdiagnosis, and overtreatment, said Dr Lyman.

In the study, the team reviewed cancer registry patient records in western Washington from 2007 to 2015 that were linked with claims from two large regional commercial insurers (Premera and Regence). They identified 2156 women who had been diagnosed with stage I (84%) or II (16%) breast cancer and were treated with mastectomy (45%) or lumpectomy + radiation (55%).

All of the women were post treatment and under surveillance, which was defined as the first 4-month gap in treatment (surgery, chemotherapy, radiation) through 13 months of observation or restart of treatment

The team tallied procedure codes for each patient for blood-based tumor marker tests (CEA, CA 15-3, CA 27.29) and advanced imaging (PET, CT, bone scan).

They found that, during surveillance, the patients averaged 2.8 tumor marker tests and 1.5 images. They also averaged 13.3 physician visits during this initial period of surveillance. Oncologists and primary care physicians were the most commonly visited specialists, with an average of 3.7 visits each.

Dr Lyman told Medscape Medical News that there are some indications for such testing in these women but that such tests should be performed at baseline, not during surveillance.

"These may be warranted at baseline in high-risk patients (stage 2B or 3), including those with large tumors >5 cm or with >3 positive lymph nodes," he said. "If negative, these tests do not have to be repeated unless the patient develops suspicious symptoms or signs, such as persistent pain, a lump, or other possible symptoms of recurrent disease."

A study limitation is that the data do not indicate definitively whether a test was medically warranted.

Dr Lyman said the reasons for the testing might be physicians' lack of education regarding the downside of imaging, such as false positives and overtreatment and false negative/false reassurance, as well as not knowing about the ineffectiveness of blood tests in detecting recurrence earlier in asymptomatic patients.

"Finally, there is the fear of litigation if the tests are not ordered and a recurrence occurs," he said. But that should not be an issue, given the ASCO guidelines, Dr Lyman added.

Patients themselves might be behind some of the testing, said Laura Spring, MD, a breast medical oncologist at the Massachusetts General Hospital Cancer Center in Boston, who was asked for comment.

"It is certainly probable that some of the testing deemed inappropriate was driven by patient request," she told Medscape Medical News.

"It is important to counsel patients on the reasons why routine imaging and blood work are not recommended. However, the threshold to obtain symptom-driven testing tends to be low," she commented.

The study authors also reported that the costs for patients undergoing these advanced procedures were considerably higher than the average $18,403 during the surveillance period. However, the cost differences were not revealed in the poster.

The new study should be a warning regarding overtesting and its costs, said Dr Lyman. "We believe one of the best ways we can help patients reduce their financial burden is for us to reinforce the message with oncologists that these tests have been shown to provide no benefit for this particular group of patients," he said.

Apparently the majority of tests were ordered by medical oncologists. The team identified physician visits within 7 days of a test or imaging charge. They found that patients had seen a medical oncologist before 74% of all biomarker blood tests and before 38% of all advanced imaging. However, this was not certain, because the data did not allow identification of the type of physician who ordered the testing.

"Both oncologists and primary care physicians need to be educated about appropriate surveillance use of tumor markers and imaging," said Dr Lyman.

"Innovative interventions" are needed, the study authors say in the poster. These could include provider and patient education, a shared medical appointment for survivorship follow-up care, and better communication between radiologists, oncologists, and patients, they state.

Dr Lyman has financial relationships with G1 Therapeutics, Halozyme, and Amgen. Other coauthors also have relationships with industry. Dr Spring has disclosed no relevant financial relationships.

American Society of Clinical Oncology (ASCO) 2017 Annual Meeting. Abstract 6582. Presented June 5, 2017.

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