Gregory J. Riely, MD, PhD
After a decade of advances in the diagnosis and treatment of patients with adenocarcinoma non–small cell lung cancer (NSCLC), the prospect for further progress remains bright, according to experts who participated in a recent OncLive
Peer Exchange panel.
There are now first- and second-line targeted therapies for both ALK
-positive and EGFR
-mutant disease. Immunotherapies have been moving closer to the front line, an important development in that most patients with NSCLC do not harbor a currently actionable mutation. And, advances in plasma genotyping give hope that eventually there will be routine clinical use of a predictive molecular proxy of tumor biology derived from a noninvasive test.
The take-home message from the roundtable, entitled “Treating Adenocarcinoma of the Lung,” is that many studies are underway to further define how best to use targeted therapies and immunotherapies with personalized approaches.
Adenocarcinomas represent 40% of all lung cancers and constitute the most dominant histological subgroup in the NSCLC category, according to the American Cancer Society. Accurately diagnosing adenocarcinomas has become more complex, panelists noted.
“In 2016, an accurate diagnosis means you understand the histology well and you have molecular testing done for that tumor because all these things drive what patients are going to get in terms of treatment,” said Gregory J. Riely, MD, PhD. “A fine-needle aspirate, simple one pass needle biopsy is not enough in 2016. We need either multiple passes with a fine needle, multiple passes with a core needle, or even surgical biopsy.”
Riely said it is critical that individual patients are tested for EGFR
mutations, ALK status, and ROS1 rearrangements; this testing should be completed within 7 to 10 days. “Randomized clinical trial data has said platinum-based chemotherapy is inferior to targeted therapy for those patients, so we need to know [mutation status] up front,” he said.
John W. Longshore, PhD
Additional testing might include BRAF
mutations and MET exon 14 skipping mutations, Riely said.
To go beyond the standard FDA-approved tests is to look for ways to make patients eligible for trials and to consider using drugs approved for other indications. Larger gene panel tests may yield information about mutations with no relevance to lung cancer but would make efficient use of tissue samples if priced in the range of single-mutation assays. The panel agreed strongly that once a biopsy has been obtained, testing for markers should be reflexively ordered.
The need to obtain sufficient tissue to conduct molecular testing has been a growing topic of discussion, noted John W. Longshore, PhD.
However, he said, “it’s not really the quantity of tissue that’s important but it’s the quantity of tumor that is important. Making sure we get a good biopsy that has sufficient tumor content really is what drives the biomarker testing landscape.” It is essential that clinicians and pathologists communicate well, noted Mark A. Socinski, MD, who served as moderator for the Peer Exchange panel. Oncologists should give the pathologist a tentative diagnosis, so he does not conduct stains to rule out a pancreatic or colon primary tumor.
Mark A. Socinski, MD
Communication is particularly important in the community setting where physicians do not have the ready access to tumor boards, Longshore said. This includes communicating with radiologists and pulmonologists. Even in the community setting, multidisciplinary tumor conferences can be conducted via Skype or another platform.
A major change in practice now emerging involves rebiopsying at progression, Longshore said. This is particularly important because of new therapies directed at the EGFR T790M resistance mutation and the need to learn a patient’s PD-L1 expression level. These markers can change over time.