Molecular Testing Strategies for Pulmonary Adenocarcinoma: An Optimal Approach With Cost Analysis

Molecular analysis of lung adenocarcinoma for therapeutically important genes is standard of practice, with multiple professional organizations recommending testing of all adenocarcinomas for mutations in EGFR, ALK, and ROS1. Some organizations recommend analyzing these genes in association with a panel. Few data exist as to optimal testing method or optimal sequence of testing from a cost perspective.

To determine which order of gene testing was least costly and whether sequential, small panel, or next-generation sequencing (NGS) was cheapest.

Recent recommendations propose a set of essential molecular tests (EGFR, ALK, and ROS1) and an optional set of molecular tests that may be useful for selection of clinical trials. We compared the costs of different testing sequencing strategies for both the 3 essential genes and for 5 optimal genes. Testing costs were determined by a survey of prices from large laboratories. The strategy most frequently rated as the lowest cost strategy was designated the optimal testing strategy.

Sequential testing of the essential genes in the order EGFR-ROS1-ALK was optimal from a cost perspective. The expected cost of sequential testing was $2227 (95% CI, $1733-$2794). The cost of NGS was $2500. The expected cost per positive result was $11,362 using this strategy.

Molecular testing of lung adenocarcinomas for the set of 3 essential genes and 5 optional genes can be performed by a variety of methods and in a variety of sequences. From a cost perspective, sequential testing in the order EGFR, ROS1, then ALK is optimal. NGS would be competitive if the price was less than $2200. NGS is optimal if testing for the 3 essential genes will be followed by testing for the 5 optional genes. NGS testing is optimal if the clinician plans to test both essential and optional genes.