Intended use for a neoadjuvant chemoradiation response prediction test for locally advanced esophageal adenocarcinoma: a survey analysis of thoracic surgeons in the US

Abstract

Objective:

A multi-analyte immunohistochemistry (IHC) based test (DecisionDx-EC

*DecisionDx-EC, Castle Biosciences, Incorporated, Friendswood, TX. Hereafter referred to as the “IHC-based test”.

) was developed and proved able to accurately predict response to neoadjuvant chemoradiotherapy (neoCTRT) in esophageal adenocarcinoma (EC) patients with locoregional disease. A survey was conducted with surgeons attending the 2013 Society of Thoracic Surgeons Annual Conference to assess their intention to change standard of care patient treatment based on predictive results obtained from this test.

Research design and methods:

Fifty-seven thoracic surgeons were provided a questionnaire regarding the current clinical management of locoregional EC patients, and their intention to change management strategy if a patient is predicted by the multi-analyte IHC-based test to experience pathological complete response (pathCR) or extremely resistant to neoCTRT (exCTRT).

Results:

Forty-four out of 46 enrolled respondents indicated that they administer neoCTRT followed by surgery to treat locally advanced EC. Fifteen (32%) respondents presently prescribing neoCTRT to EC patients acknowledged that a pathCR prediction provided by the multi-analyte IHC-based test would change their current regimens. Conversely, 28 surgeons (61%) would be willing to adjust their current strategy for patients predicted to be resistant to neoCTRT, significantly more than the case where patients are predicted to be pathCR (p = 0.01). Twenty-five percent (25%) of surgeons willing to adjust treatment in response to a patient being a potential exCTRT chose to remove CTRT from the strategy, and instead would choose surgery alone for these patients.

Conclusions:

Results from the current survey show that patients’ response to neoCTRT predicted by the multi-analyte IHC-based test has a significant influence on the decision-making process in the clinic. Nearly twice as many surgeons stated an intention to change strategy with the knowledge that the patient is likely to have extreme resistance to planned treatments than when one is a potential responder. The current survey study is limited by its ‘intended use’ nature, therefore does not reflect physicians’ real action in the clinic upon implementation of this test. However, survey results strongly suggest that use of the IHC-based predictive test is of great interest to physicians, and would likely contribute to more individualized treatment for patients with distinct sensitivity to neoCTRT.

Keywords: :

• Biomarker test
• Esophageal adenocarcinoma
• Neoadjuvant chemoradiation
• Standard of care
• Survey
• Treatment strategy

Transparency

Declaration of funding

This study was sponsored by Castle Biosciences Inc.

Declaration of financial relationships

W.S. and K.O. have disclosed that they are employees of Castle Biosciences Inc. D.M. has disclosed that he is the founder and CEO of Castle Biosciences Inc. R.D., J.C., J.K., A.K., W.L., and P.S. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work, but have no relevant financial or other relationships to disclose.

Acknowledgments

The authors thank Robert Cook and Alice Izzo from Castle Biosciences for their effort providing scientific and editorial comments on the manuscript.

Notes

*DecisionDx-EC, Castle Biosciences, Incorporated, Friendswood, TX. Hereafter referred to as the “IHC-based test”.