Arthur Sung, MD, discusses interventional pulmonary techniques in non-small cell lung cancer.
Arthur Sung, MD
Technological advancements, including endobronchial ultrasounds, have played a part in more effectively diagnosing patients with lung cancer, as well as obtaining any molecular abnormalities they may harbor. However, challenges still arise among interventional pulmonologists regarding appropriate staging language.
“We can certainly serve a very important point of function,” explained Arthur Sung, MD, on the current role interventional pulmonologists in lung cancer.
The technique with endobronchial ultrasounds has now expanded to include transbronchial needle aspirations—a novel procedure that allows practitioners to obtain a lymph node biopsy from inside the airway using a bronchoscope. This process provides an alternative to mediastinoscopy, as described on StanfordHealthCare.org.
Sung, a clinical associate professor of medicine and pulmonary and critical care medicine, Stanford Medicine, provided insight on interventional pulmonary techniques in lung cancer in an interview during the 2017 OncLive® State of the Science SummitTM on Advanced Non—Small Cell Lung Cancer. Sung: I concentrated on the diagnostic aspect of interventional pulmonology. We have a group of pulmonologists, oncologists, and other specialists involved in lung cancer care [at Stanford Medicine]. The topic, specifically, is endobronchial ultrasound; it is an advancement of the more traditional bronchoscopy where a camera is put into the windpipe and beyond to look for abnormalities of the airway.
Lung cancer staging is the most powerful predictor and a prognosticator of lung cancer treatment. The advent of endobronchial ultrasound enables us to look across the airway wall to be able to visualize the lymph nodes and directly sample under real time. That has really advanced a lot of the workflow for patients, in terms of not only getting the diagnosis of cancer, but also the staging and the molecular aspects of lung cancer. First of all, it is nonsurgical; it is done in an ambulatory basis so the patient goes home after recovering from the anesthesia technique. It can be done under moderate sedation or can be done under more general anesthesia. The camera is flexible, so it conforms to within the airways; the tip of the camera is equipped with a lens to look within the airway. It is a channel to allow the output of the biopsy instrument; it also has a miniaturized ultrasound that basically understands the anomaly of the airway.
We know where the vicinity of the lymph node is; the ultrasound basically contacts the airway wall adjacent to the lymph node. Then, we basically pass out the instrument and go through the airway wall and obtain a sample that way. Essentially, that same methodology can be repeated for all the lymph nodes on both sides. That is what I meant by not only making the diagnosis. Because of the ability to go through the lymph nodes, we can sample lymph nodes even less than 1 cm or the 5-mm range, so we have the ability to sample and stage cancer in a very efficient manner. In the world of lung cancer care, it should be a sort of a standard practice. However, knowing the most accurate staging is even language that can differ among different specialists. Unless you are on a day-to-day basis as a pulmonologist dealing with lung cancer or in a procedure of staging and diagnosis, that might not be a language [you use]. It’s very expert when you integrate yourself in a multidisciplinary care of the patients. That, to me, is probably the most challenging as a community pulmonologist; we need to engage in the proper staging language in conversations with surgical, radiation, and medical oncologists, because that really needs to align together. Our subspecialty is very device based. The endobronchial ultrasound technique has really been about looking at the testing accuracy. How does it compare with mediastinoscopy, which is what the surgeons do? It plays out nicely that we are able to achieve very similar numbers for patients in terms of sensitivity and specificity. That has been studied front and center, and that’s why it is so incorporated in standard practice.
The next step is really about using the technique to stratify whether patients could get more biologics upfront and how it integrates into the trimodality therapy of patients with lung cancer. I also feel that a lot of the clinical trials now can look at how different techniques or tools can maximize the yield. The need to identify mutations with small samples is going to be more important. An efficient way we are maximizing sample size is what we should target, in terms of making it as good and perfect as possible.
There are a lot of device-based techniques I haven’t touched on, mainly using more advanced techniques to reach within the deep part of the lung to sample small lesions much more accurately. That has not been fully utilized because patients normally undergo interventional radiology, to get a needle from outside in from the chest, but we have more advancement to using different techniques, such as electromagnetic navigation. Even in the future, [we could have] more advanced techniques to reach precisely the lung nodules that are even less then 1 cm. [There was a] transitional role of the pulmonologist, where we were really physiologists looking for whether you have a complication due to chemotherapy, drug-induced lung toxicity, where we look at the images we interpret the point-function test, and serve on a much more of a peripheral role.
But, this one example of the endobronchial ultrasound put us front and center in conversation, and I hope the audience—the community and academics—can utilize our service where we are very expert in terms of diagnosis, staging, and understanding the importance of the molecular genetics of driver mutations.