Patients with a high risk of recurrent breast cancer may not receive chemotherapy.
A widely-used gene expression test used to determine the risk of breast cancer recurrence may not be as cost-effective in a real-world setting, the authors of a study published by the Journal of Clinical Oncology found.
The new study is the first to evaluate the real-world cost-effectiveness of the Oncotype DX test, which samples 21 gene arrays. The test analyzes the risk of early-stage, favorable prognosis tumors recurring and metastasizing.
The study authors also noted that the test can help patients and physicians determine whether chemotherapy will be beneficial. Patients whose test results indicate they have a low risk of recurrence are able to forgo chemotherapy, but those with high-risk results should receive the treatment.
“As with all new technology, it’s important to assess real-world implementation to ensure what we’re offering patients is useful to them and doesn’t add to the societal and patient cost-burden, which is already very high in cancer care,” said lead author Young Chandler, DrPH, MS, MPH.
The authors examined patients who underwent the test, how many had a high risk of disease recurrence but did not receive chemotherapy, and how many patients at low risk of recurrence received chemotherapy. The study also evaluated the cost-effectiveness of the test’s accuracy.
Previous studies of the test assumed ideal conditions in which all patients received the test, providers used the risk score to determine treatment, and the test was able to accurately predict recurrence. Under these conditions, the benefit of the genetic test was relative to its costs.
“Under idealized conditions, this test is considered cost-effective. But by looking at national data, our economic analysis found that the likely cost-effectiveness ratio for Oncotype DX testing in community practice was higher than the ratios for the most commonly accepted diagnostic and preventive interventions,” said senior author, Jeanne S. Mandelblatt, MD, MPH.
In contrast with previous studies, the new findings suggest that the less than perfect accuracy of the test reduces its cost-effectiveness, according to the study.
“There has long been ongoing debate about what is good value for the money spent in oncology care. This study suggests that it will be critical to consider actual community practice in making such determinations,” Dr Mandelblatt said.
The authors explored the cost and effect of usual care for patients diagnosed with breast cancer between 2000 and 2004 before the test was used and those diagnosed between 2005 and 2012 when the test was available. The researchers conducted 100 million simulations to account for various factors. Between 2005 and 2012, test rates were 24% and chemotherapy use was 30%.
The authors found that patients younger than 50 years who were tested were less likely to receive chemotherapy compared with untested patients. This resulted in a large number of tested patients developing distant recurrences who required chemotherapy, according to the study.
In a community practice setting, treatment approaches contradicted genetic test results. Approximately 17% to 26% of patients with high risk scores did not receive chemotherapy and 8% of patients with low risk scores were treated with chemotherapy, according to the study.
The cost-effectiveness ration for testing versus no testing was $188,125 per quality-adjusted life-year (QALY) and the cost-effectiveness for ideal conditions was $39,496 QALY, according to the study. The authors noted that $50,000 QALY was the first benchmark in which benefits justified the costs.
The authors found that the cost-effectiveness of the test would be $28,947 QALY if it was perfectly accurate.
“But given the impact of other genes and factors not considered by this test, some people with low-risk breast cancer will recur, and some people with high-risk cancer will never recur, making the test have less-than-perfect accuracy,” Dr Mandelblatt said. “Still, benefits to patients are highest relative to costs in the small proportion of women at highest risk of recurrence that would not otherwise be treated without testing. That is where such testing really shines.”
However, Genomic Health, the test's manufacturer responded to the study saying that many other analyses have shown it is cost-effective.
"Cost effectiveness analyses are very complex and highly sensitive to the assumptions underlying the economic model. To truly understand the economics of diagnostic testing, it is important to look for consistency across multiple economic studies. Contrary to this single study, Oncotype DX has been shown to be cost-effective, and often cost-saving, in >20 studies across the world indicating that even with varying assumptions, practice patterns and health care costs, Oncotype DX is cost effective," Genomic Health said in a statement.