Wide Variation Found in EGFR Testing Patterns

Jonas de Souza, MD

Instructor, Medicine Department of Medicine Hematology/Oncology University of Chicago Medicine Chicago, IL

A study of patients newly initiated to erlotinib therapy for non-small cell lung cancer (NSCLC) found that there is no uniformity in the billing codes used for pharmacogenomic (PGx) testing prior to starting the drug, making it difficult to analyze treatment patterns and cost impact.

In all, there was no evidence that PGx testing was conducted in 23.5% of patients whose records were examined as part of a retrospective study but the observation is clouded by the hodgepodge of Current Procedural Terminology (CPT) codes used for testing procedures, according to Jonas de Souza, MD, an instructor at the University of Chicago Medicine in Illinois and lead author of the study.

“In order to verify if patients are having the test before the therapy, we should try and create a single pharmacogenomic CPT code for EGFR testing,” De Souza said in an interview. He presented the results of the study at the 2012 American Society of Clinical Oncology (ASCO) Quality Care Symposium, held November 30-December 1 in San Diego, California.¹

Erlotinib inhibits the tyrosine kinase associated with epidermal growth factor receptor (EGFR). In key studies that led to the FDA’s 2010 expanded approval of erlotinib (Tarceva) as maintenance therapy in NSCLC, patients with mutations of EGFR had better survival results compared with the control arm. While a statistically significant survival benefit was observed in all patients, the benefit was more pronounced in the EGFR-mutated subgroup.

Figure. Patterns of EGFR Testing¹

CPT indicates Current Procedural Terminology; PGx, pharmacogenomics.

De Souza and colleagues noted that erlotinib costs approximately $5000 per month. Since the benefits are more pronounced for NSCLC patients with the EGFR mutation, both the National Comprehensive Cancer Network (NCCN) and ASCO recommend PGx testing for the mutation prior to administering erlotinib in the first-line setting. The NCCN recommends testing only patients with nonsquamous histology, while the ASCO provisional clinical opinion covers patients with NSCLC under consideration for anti-EGFR therapy who have not yet received chemotherapy or another tyrosine kinase inhibitor.Potential reasons for not conducting EGFR testing include a lack of available tissue or a clinical decision not to perform the testing, the researchers noted.

However, with new reimbursement methods set to take effect as a result of healthcare reform, making sure that patients with the mutation are the ones receiving the drug in the first-line setting is important for these novel models of patient care.

“Basically, we have these pharmacogenomic tests for EGFR, but when you go back to the payers, to the billing codes, there’s not one single code we can find for those in the database,” said De Souza.

In their study, De Souza and colleagues used integrated medical and pharmaceutical data from four Blue Cross Blue Shield plans to retrospectively identify all patients on the plans who received erlotinib between January 2011 and June 2011 and when they first received the drug. New users were defined as those who had filed no claims for erlotinib in the prior 180 days. The researchers looked for codes that indicated a malignant neoplasm of the trachea, bronchus, and lung, as well as any code indicating PGx testing and other chemotherapy in the prior 24-month period and one month after the first time they received erlotinib.

There were nearly 3.4 million members across the four plans, and of those, 125 patients received erlotinib, with 102 of those patients (81.6%) having a diagnosis of lung cancer. Of the total number of erlotinib users, 60 patients (48%) were new erlotinib users in the period defined, and 47 of those patients had a diagnosis of lung cancer. Among those 47 patients, 36 patients (76.5%) had a claim for PGx testing within 24 months, and 34 patients had a claim within six months.

The analysis also found that time between the PGx testing and when the patient first received erlotinib ranged from four days to 22 months.

Moreover, when the researchers looked at the eight different laboratories used to analyze the PGx testing, the CPT codes varied widely among the labs. Among the 34 patients who received PGx testing within six months, the most frequently used code, an immunohistochemistry test, was used for 15 of those patients. There were three tests that were used on only one member each among patients across the eight different laboratories. Each of the laboratories submitted multiple CPT codes for each member who received testing.

An average of $844 was spent on each member who received PGx testing. However, the cost of each test varied widely depending on the CPT codes used. For example, the most inexpensive test cost $5.41 per member, while the most expensive test cost $732.24 per member. Of the 34 patients, 10 members had only one CPT code submitted for the test, but some members received as many as 10 CPT codes submitted for the test.

Erlotinib (Tarceva) is shown here as a ball-and-stick model nestled in the epidermal growth factor receptor tyrosine kinase domain (gray).

De Souza said one of the major limitations of the study is that the authors did not know whether patients had been prescribed chemotherapy prior to receiving erlotinib. While PGx testing is essential for patients receiving the drug in the first-line setting, it is not as crucial if a patient has already received chemotherapy, since a benefit is observed regardless of EGFR mutation status. De Souza said this question is being addressed in a more thorough analysis that he and his colleagues will be submitting for publication in the near future.

Reference

1. De Souza JA, Gleason PP, Starner CI, et al. Erlotinib and patterns of pharmacogenomic (PGx) testing. J Clin Oncol. 2012; 30(suppl 34; abstr 182).