Likelihood of American medical oncologists (AMOs) to order molecular testing before prescribing first-line therapy in patients with stage IV lung adenocarcinoma (l-ACA).

Abstract

e18009 Background: In 2009 we documented plans of 258 AMOs to request immunohistochemistry, FISH, or molecular testing for specific mutations prior to prescribing first-line therapy in a patient with stage IV L-ACA and PS 1 (Green et. al. J Clin Oncol 28: a7568, 2010). In 2010, we continued to use Challenging Cases, our extensively tested, live, market-research vehicle, to quantitate plans for biomarker testing, again using a specific case scenario of a former smoker patient with stage IV L-ACA and PS 1. Following ASCO 2010, we maintained the case scenario but modified the list of testing options in light of new data on EML4-ALK at ASCO 2010. Methods: In 2009, 72% (May 09), 56% (Aug 09) and 54% (Sept 09) of participating AMOs planned “no molecular testing”, while specific EGFR mutation testing alone was planned by 4%, 15%, and 10% of AMOs, respectively. In two assessments done in April and May, 2010, (N=194) rates for “no testing” were 55% and 56%, while 25% of the AMOs at each session indicated a preference for EGFR mutation testing alone, and 14% and 6% indicated plans to request both EGFR and KRAS mutation testing. After ASC0 2010, 34% of AMOs (total N = 186) assessed still favored a “no testing” plan (36% in Sept 10; 32% in Oct 10), while 26% indicated they would request EGFR mutation testing alone, 8% EGFR and KRAS mutation testing, 13% EGFR mutation and EML4-ALK assessments, and 18% testing for all 3 variables. Results: See table. Conclusions: Over the past two years, an increasing proportion of AMOs have come to favor molecular testing prior to initiating 1st line therapy in a patient with stage IV L-ACA . Approximately 1/3 of AMOs assessed after ASCO 2010 still favor no testing. The most commonly planned test is for EGFR mutation either alone or combined with KRAS or/and EML4-ALK related studies. Testing dates and number of respondents per session Testing plans 5/09 8/09 9/09 4/10 5/10 9/10 10/10 None 72% 56% 54% 55% 56% 36% 32% EGFR mutation 4% 15% 10% 25% 25% 22% 29% EFGR and KRAS mutations N/O N/O N/O 14% 6%% 8% 8% EGFR and EML4-ALK N/O N/O N/O N/O N/O 14% 13% EGFR/KRAS mutations and EML4-ALK N/O N/O N/O N/O N/O 16% 13% Other 25% 31% 35% 6% 13% 3% 5%