Treatment Options Before and After Surgery for Early-Stage Non-Small Cell Lung Cancer

November 8, 2023
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In this podcast, Cancer.Net Associate Editor for Lung Cancer, Dr. Charu Aggarwal, and Cancer.Net Specialty Editor for Thymoma, Dr. Ryan Gentzler, discuss what people with early-stage non-small cell lung cancer should know about their treatment options before and after surgery, called neoadjuvant therapy and adjuvant therapy, respectively.

Transcript: 

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ASCO: You’re listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the voice of the world's oncology professionals. 

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guests’ statements on this podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. Cancer research discussed in this podcast is ongoing, so data described here may change as research progresses.

In this podcast, Cancer.Net Associate Editor for Lung Cancer, Dr. Charu Aggarwal, and Cancer.Net Specialty Editor for Thymoma, Dr. Ryan Gentzler, discuss what people with early-stage non-small cell lung cancer should know about their treatment options before and after surgery, called neoadjuvant therapy and adjuvant therapy, respectively.

Dr. Aggarwal is the Leslye Heisler Associate Professor of Medicine in the Hematology-Oncology Division at the University of Pennsylvania’s Perelman School of Medicine. Dr. Gentzler is a thoracic medical oncologist and Associate Professor of Medicine in the Division of Hematology/Oncology at the University of Virginia (UVA) Comprehensive Cancer Center.

View disclosures for Dr. Aggarwal and Dr. Gentzler at Cancer.Net. 

To begin, Dr. Gentzler will discuss what people with early-stage non-small cell lung cancer should know about neoadjuvant treatment options before lung surgery. Welcome, Dr. Gentzler.

Dr. Gentzler: Hi, this is Ryan Gentzler from the University of Virginia. We're here to discuss the role of neoadjuvant chemotherapy and immunotherapy for the treatment of locally advanced non-small cell lung cancer. So first, I thought I'd address some of the data and definition of what is neoadjuvant treatment. So when we think about treating lung cancer that is not metastatic, that is earlier stage disease, there typically involves multimodality treatment. Sometimes these lesions or tumors can be very small and can be stage I and treated with surgery alone or perhaps radiation alone and no further treatment is needed. But the vast majority of lung cancers that are considered early stage are in fact either larger tumors, involve lymph nodes, and typically fall into the category of stage II or III lung cancers. And these are cancers that often require multiple treatments beyond the local surgery approach alone.

When we think about how we deliver that treatment, it can either be given before surgery or after a surgery. If we give treatment before a surgery, we call that neoadjuvant. If it is given after the surgery, we call that adjuvant. And most of the data that we have today in lung cancer uses one or the other of these approaches, and we don't typically give treatments both before and after, at least in terms of the chemotherapy part of that treatment.

Historically, most of the data exists in the adjuvant treatment of lung cancer going back several decades that showed that the benefit of chemotherapy after a surgery, particularly for those with stage II and stage III lung cancer, derived a clear benefit of survival by giving chemotherapy after surgery. More recently, with the advent of immune therapy, which we have used in patients with stage IV lung cancer as well as those with stage III lung cancer who cannot undergo surgery, those immunotherapy drugs have been shown to improve overall survival and improve clinical outcomes for a wide range of patients with more advanced disease. And so in the last 4 or 5 years, we have really looked at new trials that have added immunotherapy in what we call perioperative space, either before surgery or after surgery for those that have surgically resectable disease.

I'm going to focus on the neoadjuvant approaches that we have seen today, and this largely all started with data from Patrick Forde out of Johns Hopkins and Jamie Chaft from Memorial Sloan Kettering looking at single agent treatment with nivolumab immunotherapy. This was no chemotherapy given for 3 treatments prior to or three cycles prior to surgery. And that trial demonstrated a high degree of patients with tumor reduction and more importantly, we saw that the pathologic response, meaning how much tumor was left under the microscope at the time of surgery, was higher than what anyone anticipated with just immunotherapy alone. That launched a whole series of larger randomized prospective trials evaluating largely the combination of chemotherapy and immune therapy prior to surgery.

Now, before we get into some of the results of these trials, I really wanted to emphasize some of the theoretical advantages to neoadjuvant approach. Now, the first potential advantage of giving neoadjuvant treatment is that we know when you start with immunotherapy and chemotherapy regimens and that's the first type of treatment, everyone is guaranteed to get that treatment. And we know that the completion rate prior to surgery is higher than it is after surgery. These patients can get all of the prescribed treatment and will be more likely to get it than if they get it after surgery. So this is one advantage. The other is potentially starting these medications which go throughout the body and treat the cancer, wherever it may be, earlier. We know that one of the risks of all cancers, but lung cancer in particular, is that even with good surgery and removing all of that cancer, there is a chance that there are cancer cells left behind, which leads to risk of recurrence in the years to come after surgery. Naturally, if we start the treatment that can eliminate those cancer cells, wherever they may be, and do that first, perhaps we catch this earlier with fewer cells that have escaped and have a more likely chance of success of eliminating the cancer and resulting in a cure.

The third, I think, is one that we still have yet to learn more about, but if we give immunotherapy in particular, these are medications that activate the immune system, particularly the type of immune system cell called a T cell. If that T cell is able to recognize tumor cells, it is more likely to be able to continue to attack those tumor cells. And if we give that treatment prior to removal of the tumor, perhaps that activates the immune system in a more robust way that it can go after these cancer cells and eliminate those that are left behind after the surgery. If you give the immunotherapy after a surgery and the bulk of the tumor, most of the cancer cells have been removed, it may be harder to find those antigens or foreign proteins that are expressed in cancer cells. So the immune system may not be as robustly able to go after cancer if you give it solely after a surgery.

Another potential advantage of neoadjuvant approaches is that it really helps us learn as oncologists how well a cancer is responding to a treatment. If we give these treatments for 4 cycles after a surgery, we don't know whether it's eliminating those residual cancer cells or whether it is totally ineffective. If we give it before a surgery and we see that there is tumor reduction or that there is a complete elimination of the cancer, we know that that treatment was an effective treatment at attacking the cancer cells and eliminating them. We know that the cancer was sensitive to that treatment. We can then better prognosticate how well the patients are going to do after surgery. We know based on the latest data that if you achieve what we call a pathologic complete response with chemotherapy and immunotherapy prior to surgery, meaning there are no cancer cells left when we look at that surgical specimen under the microscope, we know that those patients have a much better likelihood of surviving for longer periods of time than those who have active cancer at the time of surgery after prior treatment. And so neoadjuvant approaches allow us in a 2-month time frame to get a great sense of how well our treatments are working and able to prognosticate outcomes based on how well those cancer cells have been eliminated at the time of surgery.

One large phase 3 trial called the CheckMate 816 trial was a randomized phase 3 trial and that enrolled patients with stage IB through IIIA non-small cell lung cancer using the old staging system of the 7th edition. These would all now be categorized as stage II and stage III non-small cell lung cancer patients. And it randomized these patients to 3 cycles of chemotherapy plus nivolumab, which is an immunotherapy drug, and compared that to patients treated with chemotherapy alone for 3 cycles. After these 3 cycles of chemotherapy, which is about a 9-week time frame, patients had surgical resection of their tumors. And then after surgery, patients received no further treatment, although treating physicians were allowed to give additional treatments like chemotherapy or radiation if they thought it would be beneficial for these patients, although it was not mandated by the study. One of the first results we saw from this study was that there was a much higher rate of pathologic complete response of 24% of patients achieving a path CR [pathologic complete response] with the nivolumab plus chemotherapy combination compared to only 2.2% with chemotherapy alone. This was highly statistically significant and demonstrated a clear benefit for those receiving the immunotherapy. The other main endpoint of this study was event-free survival, meaning that the time that the patients were alive and without any significant event like cancer progression or death after the enrollment of the trial. And in this analysis, the median event-free survival was significantly longer in those who have received the immunotherapy plus chemotherapy combination prior to surgery.

One of the potential concerns about neoadjuvant treatment is that it may render patients unfit for surgery who otherwise could have had their cancer removed. When we look at the outcomes from this CheckMate 816 trial, it actually did not appear to be the case to a large degree. In fact, those that got the nivolumab plus chemotherapy combination were more likely to proceed on with surgery, and the majority did; 83% received the planned surgery. There were patients who were unable to receive surgery due to adverse events of their treatment, but that was only 1% of patients enrolled in the trial. Other reasons for canceling the surgery included disease progression, meaning the cancer got worse to the point where they could not undergo surgery, or other reasons, such as the patient declined surgery, or it was found to be unresectable at the time the surgeon wanted to remove the cancer, or poor lung function.

One of the insights we got from the surgical data from this trial were that those who received the combination of chemotherapy and immunotherapy had slightly higher rates of smaller surgeries like a lobectomy compared to a pneumonectomy for those who had received [chemotherapy alone.] There were also fewer numbers of patients who required a conversion from a minimally invasive surgical procedure to an open surgical procedure if they were getting the immunotherapy combination. A higher number of patients also were able to have complete resection of their tumor if they received the immunotherapy/chemotherapy combination. The length of hospitalization was slightly lower, and the rates of pain were slightly lower in those who received the combination as well. These comparisons were not statistically significantly different, but numerically, there seems to be at least a trend toward benefit in surgical outcomes in this neoadjuvant chemotherapy/immunotherapy approach. And I think this makes sense. We know that this combination is more able to eliminate a cancer and make it a pathologic complete response when we look at it under the microscope, and therefore, if there is shrinking the tumor to a higher degree, naturally, it seems there would be more likely of completely removing the tumor, using a smaller incision to remove that tumor, shortening the length of stay in the hospital and recovery time and pain control. All makes sense if we know that the treatment itself is able to reduce that size of the tumor.

There are many other phase 3 trials ongoing studying the impact of immunotherapy plus chemotherapy in the neoadjuvant setting. The AEGEAN trial has recently reported data at the AACR meeting this year in 2023 with similar results that we saw with the CheckMate 816 trial. There are 3 other phase 3 trials that are ongoing, one of which we will see later this summer called the KEYNOTE-671 trial evaluating pembrolizumab plus chemotherapy in the neoadjuvant setting and then 2 other trials evaluating nivolumab, the CheckMate 77T trial, or atezolizumab in the IMpower030 trial.

Each of these more recent trials typically have used 4 cycles of chemotherapy plus immunotherapy prior to surgery and also continued the immunotherapy after surgery for a period of time, most commonly approximately 1 year. From the data we have seen so far, it remains uncertain whether additional immunotherapy beyond the 3 or 4 cycles given in the neoadjuvant setting provides any additional benefit. We still do not understand what to do with patients who did not achieve a pathologic response whether further treatment would be of any additional benefit. We do not know if there will be further benefit even in those that achieved a pathologic complete response whether a slightly longer duration of immunotherapy would further improve outcomes in that group. We suspect with longer-term follow-up over the years of all of these phase 3 trials that some of these questions will be answered.

So what are some key questions that patients should ask when considering a neoadjuvant chemotherapy/immunotherapy approach? I think the first question that's key is what is my tumor stage? We know that the trials that enrolled patients with a neoadjuvant approach enrolled patients using our current staging system would be a stage II or stage III lung cancer. And this is where it gets really tricky is, what subdivision of stage III is it? We tend to think of stage IIIA's as being one that it would be surgically resectable, with a smaller number of stage IIIBs, and then stage IIIC, one that we would not typically recommend surgery for. I think the next question within the tumor stage is, is this based on imaging or based on the biopsies? And we know that biopsies are really the best way to stage locally advanced cancers, particularly getting samples of lymph nodes in the mediastinum. Sometimes what looks like a stage I or stage II on imaging is, in fact, a stage III based on biopsies that are done at the time of surgery. It's ideal to know that information prior to making the decision about surgery so that that surgery is not futile.

 

On the opposite side, sometimes there is imaging suggestive of lymph nodes that are enlarged in the mediastinum, and it's presumed that this is a more advanced stage III and is not surgically resectable. However, if you go and biopsy those lymph nodes, sometimes they are benign. Sometimes they are inflammation related to infection or cancer but do not actually contain cancer cells. And so we typically advise that getting biopsies of lymph nodes in the mediastinum, at least any that are particularly suspicious, is highly recommended for these locally advanced cancers.

I think the next question that's key to ask is, what are my tumor biomarkers? And there are multiple biomarkers that we look at in non-small cell lung cancer that help us decide what is the best treatment. What is the best approach? What is the best medicine to treat the cancer? We know that one of these biomarkers that is a key is a mutation. So multiple different mutations can occur in lung cancers, particularly those that are adenocarcinoma subtypes. And these mutations may be less likely to benefit from immunotherapy and we may want to take a different approach with surgery, chemotherapy, and potentially targeted therapies that specifically target that mutation that exists in the tumor.

The other key biomarker here is PD-L1. We know that tumors with a higher level of PD-L1 are more likely to respond and benefit from immunotherapy. As of right now, that PD-L1 status plays a more important role in the adjuvant setting. All of the chemotherapy plus immunotherapy combinations in the neoadjuvant setting seem to benefit the group as a whole regardless of that PD-L1 status. But still, an important biomarker that we should have prior to making all final decisions on treatment. I think another question that should be asked any time you have an earlier stage cancer is, is my tumor surgically resectable? And there can be many reasons why cancers are not resectable, perhaps due to the anatomy of where the tumor is located, if it invades into the mediastinum, for example, or is near large blood vessels, or perhaps because there are too many lymph nodes and this is a more advanced stage.

And so I think the main reasons for not being surgically resectable would be the tumor is too large, if the stage is too high, or is it more of a function of fitness for surgery and that can be because of other underlying lung disease. Perhaps removing part or all of a lung would not be safe due to impaired lung function to begin with. And I think it's important to understand that sometimes stage III lung cancers are resectable and sometimes they are not, and understanding the reason why they are not, I think, is important. And then I think lastly and ultimately when we're talking about a neoadjuvant approach, you want to ask your treating oncologist, "Would it be better to give my treatment before surgery or after surgery?" And really discuss the pros and cons with the physician and have them incorporate all of the factors that go into these treatment decisions. How well you'll tolerate chemotherapy, other medical conditions that may play a role in the likeliness of getting through those treatments safely, perhaps underlying diseases that may increase the risk of immune-related side effects with immunotherapy. You really want to factor in all of these things and discuss the pros and cons of a systemic treatment first versus surgery first before making final decisions on how to treat locally advanced lung cancer. All right. Thank you.

ASCO: Thank you, Dr. Gentzler. Next, Dr. Aggarwal will discuss what people with early-stage non-small cell lung cancer should know about their adjuvant treatment options for after lung surgery.

Dr. Aggarwal: This is Dr. Charu Aggarwal. I'm the Leslye Heisler Associate Professor for Lung Cancer Excellence at University of Pennsylvania's Abramson Cancer Center. And today I will talk to you about the use of adjuvant immunotherapy in the setting of early-stage non-small cell lung cancer. We'll start by discussing what adjuvant therapy is, what types of options we have for adjuvant therapy, what kind of testing is important, and what options there may be in terms of adjuvant immunotherapy. So let's get started. Early-stage lung cancer comprises of stages between stage I to stage III. These stages vary by the size of the tumor as well as the level of lymph node involvement.

In the setting of very early-stage lung cancer, such as stage I and stage II, as well as some select stage III lung cancers, we recommend surgical resection. And in these patients, the use of additional treatment is recommended based upon the pathological determination of the tumor size as well as the lymph node status. If usually lymph nodes are involved, we recommend adjuvant chemotherapy, and also, many experts will deliver adjuvant chemotherapy for tumors that may be larger than 4 centimeters even in the absence of lymph node involvement. The data for adjuvant chemotherapy comes from several large clinical trials that were conducted about a couple of decades ago now that demonstrated not only an improvement in preventing recurrence of the cancer but also a modest improvement in overall survival, really laying the ground for improvement and therefore becoming the gold standard. Four cycles of chemotherapy are usually administered about 6 to 12 weeks following surgical resection, and this is really the basis of our treatment in the early-stage setting.

In today's time and age, we now have several other options. We have treatment options that include molecular therapy, which is biomarker driven, as well as the use of immunotherapy. So it's actually very important for us in the adjuvant setting--or in the post-surgical setting--to test for mutations such as EGFR. It's also important for us to test PD-L1 status. So let's dive into why each of these may be important. Patients with EGFR mutations, especially those with sensitizing mutations in EGFR exon 19 or 21, now have the opportunity to receive a targeted therapy in the form of osimertinib, which is an oral drug, very targeted and specific for the EGFR mutation that has been studied in a clinical trial setting in patients with early-stage non-small cell lung cancer. In patients with stage IB to IIIA non-small cell lung cancer with EGFR mutation, use of osimertinib was associated with a significant improvement in our ability to delay the recurrence of cancer. Based on this significant improvement, FDA approved therapy with osimertinib, and it is currently available and ready to use. We usually recommend it for 3 years, so daily therapy for 3 years, and patients are monitored with routine CAT scans and lab work.

For patients who don't have an EGFR mutation, we do recommend broad panel testing. Of course, this is not the standard, but I think it's important for us to identify patients who may not benefit from immunotherapy. Patients that have an ALK mutation, for example, or ROS1 translocation, may not have the best chances of responding to adjuvant immunotherapy, and therefore, I think testing should be performed to make sure that we are having a shared decision-making conversation with our patients about the use of the correct adjuvant options.

In terms of adjuvant immunotherapy, we now have 2 approved agents. One of them is atezolizumab, and the other one that was just recently approved is pembrolizumab. Atezolizumab was approved on the basis of a large clinical trial called the IMpower010 study, which randomized 1,280 patients with stage IB to IIIA non-small cell lung cancer to either 1 year of atezolizumab or best supportive care. Of note, all of these patients had to have had adjuvant chemotherapy that included a cisplatin platinum chemotherapy. In the first analysis, we found that the disease-free survival or the probability of the patients remaining cancer-free was significantly improved in those patients that had a tumor expression of PD-L1 greater than or equal to 1% and received atezolizumab compared to patients who did not receive atezolizumab.

On the basis of this positive primary endpoint, the U.S. FDA approved the use of adjuvant atezolizumab for patients with stage II to IIIA resected non-small cell lung cancer after surgical resection and adjuvant chemotherapy. Recently, we heard that this does lead to small but significant improvement in overall survival. There is a trend towards improvement in overall survival. However, the data are quite immature at this point, and we do need longer follow-up to be able to follow this trend. The greatest magnitude of overall survival benefit was found in patients who had the PD-L1 greater than or equal to 50%. So it's important to know what the PD-L1 level of a patient may be when I'm thinking about adjuvant immunotherapy because adjuvant immunotherapy is most likely to benefit those that don't have an actionable mutation, such as EGFR, and those that have the highest PD-L1 staining, at least in the IMpower trial.

Secondly, the PEARLS clinical trial is a clinical trial that evaluated the use of pembrolizumab, which is another immunotherapy agent, again, in the adjuvant setting. For this clinical trial as well, there was a small but significant improvement in disease-free survival, again preventing the probability of recurrence in all patients that received pembrolizumab compared to the best supportive care. And basically, this led to also an approval by the FDA for the use of pembrolizumab. Again, now we have 2 options. Both of these are administered for 1 year.

What should patients know about therapy? These drugs are usually administered once every 3 weeks. They are given intravenously. Sometimes, we can change the treatment schedule to be either once every 4 weeks in the case of atezolizumab or every 6 weeks in the case of pembrolizumab. These may be associated with some side effects. Immunotherapy side effects that are most common are fatigue, chills, myalgias, or basically a feeling of pains in the body or joints.

But also, some serious life-threatening reactions can occur such as activation of the immune system to such an extent that the immune system may start to attack the body's organs. So this may lead to swelling or inflammation in the organs that may manifest itself as colitis if the gut gets inflamed, or pneumonitis if the lungs were to get inflamed, or pancreatitis if the pancreas were to get inflamed. Any organ in the body can really get inflamed. We've certainly seen cases of thyroiditis. We've seen cases of polyarthritis. We've seen cases where the brain may also get inflamed or the pituitary may get inflamed. So there are definitely some life-threatening reactions or side effects that can occur with the use of immunotherapy that should be closely monitored. The benefit of having used immunotherapy in the metastatic setting is that now we have a lot of experience managing these side effects. And if recognized early, these side effects can be managed appropriately with the use of steroids as well as holding therapy. Many of the times, we can even reinstitute immunotherapy without significant harm to the patients. However, I think immunotherapy benefits as well as side effects should be discussed in detail with the provider, especially in the adjuvant setting.

Patients may ask if neoadjuvant immunotherapy along with chemotherapy is a better approach compared to adjuvant immunotherapy. At this time, we don't have a clinical trial that is comparing neoadjuvant chemoimmunotherapy followed by surgery to an approach that is surgery followed by adjuvant immunotherapy. In general, I would say that if the decision by a multidisciplinary team has been made to proceed with surgery, careful discussion should be had about adjuvant chemotherapy as well as the use of adjuvant immunotherapy, and molecular testing should be performed. All patients with early-stage disease should have a multidisciplinary tumor board discussion, which includes engagement with surgeons, radiation oncologists, pulmonologists, pathologists, and medical oncologists so that they can ensure that many experts have had the chance to weigh into their case as well as come to the right conclusion on whether or not to use new adjuvant chemoimmunotherapy or just to proceed with surgical resection.

ASCO: Thank you, Dr. Aggarwal. You can learn more about neoadjuvant and adjuvant treatment options for early-stage non-small cell lung cancer at www.cancer.net/lung.

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