Cornerstone of personalized medicine
In their article, Dr. Pritchard and colleagues note that more than 90 targeted therapies have been approved by the U.S. Food and Drug Administration for use in eligible cancer patients. An estimated 55% of recent oncology trials involved the use of biomarkers.
Predictive biomarker testing to identify patients who may benefit from targeted therapies “is a cornerstone of personalized medicine in cancer care, allowing for more rapid diagnosis while informing treatment decisions that could lead to better patient outcomes and systemic efficiencies,” they emphasize.
However, providers “face several challenges” when integrating biomarker testing and targeted therapeutics into cancer care, and the use of biomarker testing varies widely across tumor types, biomarkers, and practice settings.
For their study, the team examined the use of targeted therapy in advanced NSCLC using data from the Diaceutics Data Repository, which includes commercial and Medicare claims, as well as laboratory data.
They focused on 38,068 patients with actively managed advanced NSCLC. Of those patients, 50.80% were women, and 64.6% were aged 71 years or older. The vast majority (84.50%) were non-Hispanic White patients.
The team examined the impact of seven clinical practice gaps on the timeline from ordering a biopsy to delivering targeted treatment. They then normalized the results to a standard patient population of 1,000.
In 6.6% of cases, an initial tissue or liquid biopsy was never performed, meaning that 66 of the 1,000 patients could not progress toward targeted therapy.
Among those who underwent a biopsy, for 4.0%, there was insufficient tissue on the initial biopsy, while for a further 0.97%, there was insufficient tissue on re-biopsy. Moreover, 9.6% could not undergo biopsy testing because of a lack of tumor tissue. Consequently, a further 136 of the 944 remaining patients were lost.
For the third clinical practice gap, the tumor cell content was overestimated in 1.7% of patients. As a result, their biopsy specimen could not be tested because it did not meet the threshold requirements. This resulted in the loss of a further 14 patients.
Moreover, for a further 17.5% of patients, biomarker testing was not ordered at all, owing to cost concerns, a lack of access to testing, a lack of awareness of testing options, and low confidence in the results, among other reasons. An additional 0.6% began treatment before any testing was ordered; together, that accounted for 142 patients being lost.
Even among patients who underwent biomarker testing, 14.5% had uninformative or inconclusive results, and 3.9% had false-negative results, meaning that a further 118 patients were lost.
In another 4.0% of cases, the results of biomarker testing did not arrive within the treatment decision window, owing to delays in reporting the results, and so for these patients, treatment began without the results being taken into consideration. A further 21 patients were lost.
The final clinical practice gap was not choosing the appropriate targeted treatment on the basis of test results. The researchers found that of 27,186 patients who underwent biomarker testing and received a timely result, 29.2% were not given the corresponding therapy. This resulted in the loss of a further 147 of the original 1,000 patients.
Overall, the team calculated that 64.4% of patients newly diagnosed with advanced NSCLC “are not benefiting from precision oncology care options appropriate for their diseases and will likely have suboptimal outcomes.”
The research was supported in part by the Personalized Medicine Coalition, a nonprofit 501c3 organization dedicated to the advancement of personalized medicine. Dr. Pritchard is an employee of the Personalized Medicine Coalition. A coauthor has relationships with Thermo Fisher Scientific, AstraZeneca, Eli Lilly, Blueprint Medicines, and Oncocyte.
A version of this article first appeared on Medscape.com.