EXTREME TESTING IS COMMON IN METASTATIC BREAST CANCER

Despite unknown clinical benefit, excessive or "extreme" testing to monitor disease is common among elderly women with metastatic breast cancer (MBC), new research shows.

The testing that was analyzed in the study was of serum tumor markers and radiologic imaging.

In the study, more than one third of the 2400-plus women with metastatic disease were found to have had more than 12 serum tumor marker tests per year or more than four radiographic imaging tests per year.

These women were dubbed "extreme users" by the study authors.

The findings were published online May 9 in the Journal of Clinical Oncology.

"We wanted to study this issue because there are limited data on how to monitor patients in the metastatic setting," lead author Melissa K. Accordino, MD, Columbia University Medical Center, New York City, told Medscape Medical News.

"When you look at the guidelines, they are really very vague, and they don't offer a lot of details for how often people should be doing this," Dr Accordino said.

When she and her group looked at what was going on at their own center, they found that they had high rates of tumor marker use, with a high proportion of patients undergoing tests for tumor markers each month.

"This led us to see what is going on elsewhere," she said.

The researchers used the SEER-Medicare database to identify women aged 65 years and older who were newly diagnosed with MBC between January 1, 2002, and December 31, 2011, and who had undergone disease monitoring.

Billing dates of serum tumor marker tests for carcinoembryonic antigen (CEA) and cancer antigen (CA) 15-3/cancer antigen 27.29 and CT and positron-emission tomography (PET) scanning were recorded.

They also looked at factors associated with extreme use and compared total healthcare costs and end-of-life healthcare utilization in extreme users with those of women who were not extreme users.

There were 2460 women with MBC identified from the SEER database who were eligible for analysis.

Most were white (85.4%), single (60.3%), and free of comorbidities (57.3%). Most (72.5%) had hormone receptor―positive MBC, and the majority (85.7%) were alive more than 12 months from the time of their MBC diagnosis during the study period.

Of these women, 924 (37.6%) were found to be extreme users of disease-monitoring tests.

Most of the extreme use was for imaging tests, which were conducted in 807 (32.8%) of the women. Fewer women (n = 222; 9.0%) were extreme users of serum tumor marker tests.

Extreme users were more likely to be younger than 80 years, to have ER/PR-negative cancer, to have had at least one PET scan, and to have had more oncology visits, Dr Accordino said.

The analysis also showed that use of serum tumor marker tests was linked with being of higher socioeconomic status, having at least one PET scan (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.42 - 2.88), and having a higher frequency of office visits (OR, 1.72; 95% CI, 1.10 - 2.68).

Women with ER/PR-negative MBC were less likely to be extreme users of serum tumor marker tests (OR, 0.59; 95% CI, 0.37 - 0.95).

Similar associations were found with regard to extreme use of radiographic imaging, with the exception of women with ER/PR-negative MBC (OR, 1.93; 95% CI, 1.50 - 2.49).

There was no difference in overall survival in women who were extreme users of disease monitoring in comparison with those who were not, Dr Accordino said.

"These are administrative data, so it's not the same as prospective data, but still, it was an important finding. Those women who were getting closer attention, perhaps by getting more scans and tumor marker tests, were not living longer, but they were not living shorter, so you cannot make the argument that they were sicker and therefore were getting more tests," she said.

Extreme users had higher costs of care following their MBC diagnosis, from the first year of their diagnosis to the last year of their life.

For extreme users in the first year after diagnosis, costs were 50.6% higher (95% CI, 40.7% - 61.1%). The mean cost of care was $56,249, compared with $37,121 for the rest of the study population (P < .001).

Extreme users also had more aggressive and costly end-of-life care.

In the last year of life, costs were 68.7% higher (95% CI, 54.2% 0 84.6%) for extreme users, and mean cost of care was $63,697 compared with $39,843 in the rest of the study population (P < .001).

These results highlight the need for prospective studies to answer important questions about what constitutes the right degree of disease monitoring, Dr Accordino said.

"We need to have some prospective studies evaluating different strategies of disease monitoring to see what the ideal frequency of monitoring is, and also how to monitor these patients," she said.

The findings may also generate some controversy, Dr Accordino added.

"Extreme use may be reflective of both patient and physician factors, and both of these may be targeted in the future to try and reduce spending. The big thing right now is the need for better evidence prospectively to figure out the risks and benefits of such testing and to help us form guidelines," she said.

Don't Blame the Patients

Gary H. Lyman, MD, MPH, codirector, Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, and professor of medicine, public health, and pharmacy at the University of Washington, Seattle, pointed out that current guidelines from the American Society of Clinical Oncology (ASCO) and statements from ASCO for the Choosing Wisely Campaign discourage routine use of these tests for monitoring patients with MBC.

"There are no data demonstrating that their routine use improves patient outcomes, and especially advanced imaging is associated with considerable cost. Nevertheless, these tests continue to be used extensively in practice, and as demonstrated in this study, more than one third of such patients experienced extreme use of these tests, as the authors defined it," Dr Lyman told Medscape Medical News.

The factors associated with extreme use of tests are not surprising but are important to note, he added.

"It appears that extreme test use is associated with frequent clinic visits and accompanied by substantial higher overall costs. It is not surprising that the most difficult-to-treat group of patients with MBC, those with triple-negative disease, were more likely to experience extreme use as well as those with positive findings on a previous CT scan, which may be used to assess disease progression or response," Dr Lyman said.

He does take issue with the authors on one point, however.

"The only issue I might take with the authors' report is that the term 'extreme users' seems to impart a responsibility entirely on the shoulders of the patients. I would guess this is semantics and not the intended message of the authors," he said.

But Dr Lyamn stressed that responsibility for testing ultimately lies with the provider and professional organizations. More education is needed to ensure that all parties know that there is a lack of supporting evidence for such practice and that clinical guideline recommendations do not support these practices, he said.