DOI: 10.6084/m9.figshare.27827760.v1
title: Physician preferences of biomarker testing strategies in newly diagnosed stage IV non-small cell lung cancer patients

description: <b>Aim:</b> To understand physicians’ attitudes and behaviors regarding EGFR testing and retesting strategies in newly diagnosed metastatic non-small cell lung cancer patients. <b>Materials & methods:</b> Oncologists and pathologists completed an online, cross-sectional survey. <b>Results:</b> Most oncologists (73.3%) and pathologists (53.4%) agreed that concurrent testing increases sensitivity for detecting EGFR mutations. Upon tissue insufficiency, oncologists and pathologists reported using liquid biopsy 77.0% and 39.0% of the time, respectively. Tumor accessibility, smoking status, patient willingness and age were key drivers of tissue re-biopsy. Most oncologists reported high confidence in proceeding to first-line therapy based solely on liquid biopsy (60.7–80.0%); fewer pathologists (37.9%) were comfortable with this decision. <b>Conclusion:</b> Variation in physicians’ perceptions of testing and retesting highlights the need for greater stakeholder consensus. Treatment for non-small cell lung cancer that has spread to other organs is based on a patient’s specific subtype of cancer (mutational status), which is found out through biomarker testing. The standard biomarker testing method is to take a sample of the cancer through biopsy or surgery (tumor tissue testing). However, liquid biopsy (LB), a blood test to look for signs of the cancer in the bloodstream, is becoming more common when tumor tissue is not on hand or not able to get. This study hoped to learn about different doctors’ views on blood tests and find out what elements affect biomarker testing and re-testing choices. Most oncologists (doctors who treat cancer) and pathologists agreed that doing both a tumor tissue test and blood test together raises the likelihood of finding a mutation that can help guide treatment choices. When a tumor tissue test was unsuccessful, the most important elements that decided whether to retry was ease of getting to the tumor, smoking status, patient willingness and age. Oncologists were more confident making treatment choices based only on a LB when compared with pathologists. Our study showed notable variation in choices, thoughts, attitudes and behaviors associated with testing and retesting strategies, as well as inconsistent practice patterns and a potential lack of following guidelines. Greater agreement on the role of LB is needed, as well as efforts to deal with barriers to treatment and inconsistent care, which will result in fairer and better care for patients. With the emerging relevance of using liquid biopsies to detect oncogene-driven metastatic non-small cell lung cancer (mNSCLC), it is important to understand oncologist perceptions, preferences, attitudes and behaviors toward biomarker testing in newly diagnosed mNSCLC patients with insufficient tumor tissue. This study aimed to understand from the physician perspective the drivers of decision making, and the considerations and behaviors associated with EGFR testing and retesting strategies in the context of newly diagnosed, nonsquamous mNSCLC. Among patients with insufficient tumor tissue, a majority of the oncologists preferred using liquid biopsy (LB) either alone or with tumor tissue re-biopsy. Many oncologists reported willingness to proceed to therapy based on a LB that is negative for any actionable genomic alteration, balancing accuracy with urgency and patient desires. In contrast with oncologists, pathologists’ perceptions and institutional behaviors were more in-line with published guidelines. Accessibility of the tumor, followed by smoking status, patient willingness and age were the key patient characteristic drivers for oncologists to order tumor tissue re-biopsy; existence of PD-L1 was important but secondary to these factors. As LB usage increases, understanding LB implementation in clinical practice will be important to ensure optimal biomarker testing and patient care. These results highlight the need for consensus on strategies for optional biomarker testing and care in the newly diagnosed, non-squamous mNSCLC patient setting.