Diagnostic Oncology: Reports from the IASLC Pathology Committee

The IASLC Pathology Committee at the 2018 USCAP meeting in Vancouver, Canada.

By Keith M. Kerr, BSc, MB, ChB, FRCPath, FRCPE
Posted: March 1, 2019 

There was a time, remembered by us older pathologists, when the image of pathology was that of a rather peripheral specialty, sometimes perceived to have limited clinical relevance, delivered by physicians who were never seen, rarely heard, and were usually banished to some dark corner of their hospital. We pathologists, of course, knew differently, but still we were perceived as the “back room” members of clinical practice. My, how circumstances have changed. Pathology is now at the forefront in the multidisciplinary care of patients with lung cancer. Pathologic classification, at both morphologic and molecular levels, is now a cornerstone of the treatment of patients with lung cancer in this era of precision cancer medicine.

The Players and Their Roles
The Pathology Committee of the IASLC has been a key player in important developments in lung cancer diagnosis and classification for more than 40 years. Taking the lead from the IASLC’s culture of promoting research, education, and best practices in the clinical management of patients with lung cancer, the Committee and its members have led major initiatives. Among these are several iterations of the World Health Organization (WHO) Lung Cancer classification, which have included radical changes in the understanding of lung adenocarcinoma and the integration of immunohistochemical and molecular features in day-to-day diagnostics of lung cancer. A detailed history of the panel’s membership and contributions up to 2014 has been published.1

In 2005, the IASLC Pathology Committee had several stated aims, which included: providing international leadership in clinical and scientific aspects of lung cancer pathology; supporting the IASLC through projects, publications, and meetings; integrating with other specialties in lung cancer medicine; and taking a central role in major publications, such as the WHO Lung Cancer classification. Since 2014, the IASLC Pathology committee has been busy meeting all of these aims.

The 2015 WHO classification editors included Drs. William Travis, Elisabeth Brambilla, and Andrew Nicholson, all former IASLC Pathology Committee chairs. Several committee members were involved in the update of the College of American Pathologists/ IASLC/Association for Molecular Pathology guidelines for testing lung cancer for kinase inhibitor targets.2 Committee members produced an updated IASLC Atlas of ALK and ROS1 Testing in Lung Cancer, as well as two new atlases on PD-L1 and EGFR mutation testing. All of these atlases are immensely popular.

A considerable amount of the Committee’s time and effort was taken up recently by the Blueprint project. This was a collaborative endeavor involving both IASLC pathologists and the pharmaceutical industry. Credit is due to Dr. Fred Hirsch, a longstanding Pathology Committee member and past-CEO of the IASLC, for his tireless efforts and determination in bringing parties together and securing important funding for this complex work. The Blueprint project has clarified a number of difficult questions that have plagued the world of PD-L1 immunohistochemistry testing in lung cancer, including the technical comparability of several of the trial-validated assays, the possibility of high interobserver agreement in PD-L1 scoring, and the comparability of cytology and biopsy samples in this testing space.3

The efforts of the committee continue under of leadership of our current Chair, Dr. Ignacio Wistuba of The University of Texas MD Anderson Cancer Center. Many important questions in lung cancer pathology need answers, and the committee members have established small working groups to address these myriad topics, with members working on several projects. Some questions are “old chestnuts” that have been hard to crack, such as the grading of lung cancer in both histology and cytology samples, recognition of invasion in early-stage adenocarcinomas, neuroendocrine tumor pathology, and the assessment of surgical margins in cancer resection specimens. Many address new questions prompted by the evolution of targeted therapies in lung cancer, especially immunotherapy. There are working groups looking at immune-related markers, tumor mutation burden, and assessment of major pathologic responses after neoadjuvant therapy.

The care of patients with lung cancer truly is a multidisciplinary effort, and we all practice lung cancer medicine in different ways.

Introducing a New Column
These undertakings come in addition to the creation of more IASLC atlases as well as contributions to future editions of the WHO classification, IASLC meetings, and other educational activities such as the IASLC webinar series. It is not difficult to see the enormous contribution that the IASLC Pathology Committee has made in the field of lung cancer pathology. In an effort to be transparent and to disseminate information in a timely manner, the IASLC Pathology Committee aims to make a regular contribution to the IASLC Lung Cancer News, highlighting interesting vignettes from the world of lung cancer pathology that we hope readers will find useful in daily practice. The care of patients with lung cancer truly is a multidisciplinary effort, and we all practice lung cancer medicine in different ways. Dr. Wendy Cooper, a pathologist from the Royal Prince Alfred Hospital, in Sydney, Australia, came up with a title for the article series that we all liked, as it reflects the close collaboration between pathology and oncology, delivering personalized medicine for patients lung cancer: Diagnostic Oncology: Reports from the IASLC Pathology Committee. Each issue will feature an article for this new column, authored by a committee member. If you have questions for the committee or a topic suggestion, email IASLC Lung Cancer News Managing Editor Joy Curzio at curziocommunications@gmail.com. ✦

About the Author: Dr. Kerr is honorary chair in Pulmonary Pathology at the University of Aberdeen, Aberdeen, Scotland. Dr. Kerr is chair elect of the IASLC Pathology Committee.

1. Tsao MS, Travis WD, Brambilla E, et al. Forty years of the international association for study of lung cancer pathology committee. J Thorac Oncol. 2014;9(12):1740-1749.

2. Lindeman NI, Cagle PT, Aisner DL, et al. Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology. J Thorac Oncol. 2018;13(3):323-358.

3. Hirsch FR, McElhinny A, Stanforth D et al. PD-L1 Immunohistochemistry Assays for Lung Cancer: Results from Phase 1 of the Blueprint PD-L1 IHC Assay Comparison Project. J Thorac Oncol. 2017;12(2):208-222

4. Tsao MS, Kerr KM, Kockx M et al. PD-L1 Immunohistochemistry Comparability Study in Real-Life Clinical Samples: Results of Blueprint Phase 2 Project. J Thorac Oncol. 2018;13(9):1302-1311

5. Kerr KM, Tsao MS, Yatabe Y et al. OA03.03 Phase 2B of Blueprint PD-L1 immunohistochemistry assay comparability study. J Thorac Oncol. 2018; October, S325