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World Lung Conference Day 2, 7/5/2011
Plenary Session: Lung Cancer in Never Smokers
The day started if with Dr. Thun from the American Cancer Society. He reviewed environmental factors contributing to Lung Cancer in never smokers. He started by reminding us that although only 10% of lung cancer deaths in men and 15-20% of lung cancer deaths in women are due to nonsmoking cancer, the burden of suffering caused by non-smoking lung cancer is actually rather high. If non-smoking lung cancer were treated as its own disease, separate from smoking-driven lung cancer, it would rank eighth among the most common fatal cancers in America! He reviewed environmental factors known to cause lung cancer: secondhand smoke, radon, asbestos, certain metals, some organic chemicals, radiation, air pollution, tubercoulosis, and other chronic inflammatory conditions. Others exposures likely also play a role, but have yet to be proven: human papilloma virus and chronic inhalation of cooking fumes and incense. Indoor air pollution from cooking, coal burning, and smoking men may explain the extraordinarily high rate of nonsmoking lung cancer among women in some areas of Northern China.
Dr. Pierre Massion of Vanderbilt took the stage second to talk about the molecular pathogenesis of never smokers. He reminded us of the different histologic tendencies of never smokers—less SqCC, more adenocarcinoma including the multiple subtypes once called BAC. He reviewed genes associated with susceptibility including cyp1a1, gstm1, xrcc1, gpc5, and fam38b. He pointed out the role of genetic differences in key molecules in inflammatory pathways: IL-1b, IL6, and IL1RN. Finally, insults from the environment may be expressed differently based on variations in genetic susceptibility.
Dr. Massion then used the figure, reproduced below, from Pao et al, Lancet Oncology 2011 to remind us how far we have come in understanding the molecular drivers in nonsmoking cancer:
Studies have shown particular genomic signatures in never smokers. But not only is the DNA changed, but DNA modifiers (epigenetics) are also changed and we have defined specific genes whose expression is modified.
Details on the Debate over Who to Test and for What Molecular Markers
The following is laden with personal opinion as much as actual evidence. Feel free to take it or leave it.
In my last post, I introduced the key questions we’re facing in my own institution, and many other oncologists and their own hospitals are doing the same thing: which patients do we now routinely test for molecular markers in their lung cancer tumors, and what markers do we request? Here’s an outline of the questions where there’s still back and forth, and why:
“Reflex Testing” in Lung Cancer: Who to Test and When?
It’s probably the biggest debate in lung cancer right now, and the answers are evolving every few months:
1) Which patients should be tested for molecular markers like EGFR, KRAS, ALK, etc.?
2) What tests should be sent?
3) When should these studies be sent? Right at the time of diagnosis (“reflex testing”), or after an oncologist has assessed how important these tests are really going to be, and decide which studies to send accordingly?
This morning, I and my colleagues debated some of these issues in our multidisciplinary thoracic oncology tumor board session, which brings together medical oncologists, our thoracic surgeons, radiation oncologists, pathologists, radiologists (including our interventional radiology colleagues who get many of the biopsies), and pulmonologists. We wanted to develop a set of guidelines for our institution about whether we should be sending off these markers from the pathology lab even before these patients find their way to an oncologist or not, since most patients may go at least a few days and sometimes a week or two between the diagnosis of lung cancer being established and them seeing an oncologist to shape the plan.
There are a few background points to clarify. First, having more tissue is always better, and this is a shift from the way things have always been in lung cancer, when just getting a few cells from a fine needle aspirate was enough to make a diagnosis of NSCLC vs. SCLC, and that was all you needed. These days, NSCLC subtype in terms of histology — adenocarcinoma, squamous, large cell neuroendocrine, etc. — are now routinely used in shaping our recommendations about one treatment or another. And now the potential to dramatically alter the course of someone’s treatment by identifying a mutation associated with a high probability of a prolonged response to a targeted therapy raises the stakes.
Challenging Cases in Lung Cancer Podcast Series: Adjuvant Chemo for a Small NSCLC Tumor with a Satellite Lesion
This is the first of a series of podcasts we’ve done, developed in partnership with LUNGevity Foundation, in which I present the same challenging cases in lung cancer management to a series of experts to learn the range of views offered by them, then the multiple thoughtful comments by all of them discussing the same single featured case for each podcast. The first discussants in each podcast will be Drs. Bob Doebele from University of Colorado and Jyoti Patel from Northwestern University, who are then followed by other terrific colleagues of mine:
- Dr. Suresh Ramalingam, from Winship Cancer Center, Emory University in Atlanta, GA,
- Dr. Jonathan Goldman, from Premier Oncology in Santa Monica, CA.
- Dr. Julie Brahmer, from Sydney Kimmel Cancer Center at Johns Hopkins University, in Baltimore, MD
- Dr. Heather Wakelee, from Stanford University Cancer Center in Palo Alto, CA
- Dr. Karen Reckamp, from City of Hope Cancer Center in Duarte, CA
Our first case is a discussion of how they would approach a patient who has a small primary tumor that also has a separate microscopic satellite lesion nearby. Here’s the links to the audio and video versions of the podcast (there isn’t a lot of video to see, by the way), along with the transcript:
case series: small nsclc tumor w/satellite lesion video podcast
case series: small nsclc tumor w/satellite lesion audio podcast
case-series-small-nsclc-tumor-wsatellite-lesion-transcript
Podcast: Play in new window | Download (26.9MB) | Embed
New Hope for EGFR Mutant NSCLC with Acquired Resistance to Tarceva (including T790M!)
I am sorry to say that there were few surprises or earth-shatteringly positive results at this year’s ASCO meeting in Chicago (unless you count my button-shattering belly expansion from too many pizza lunches and dinners). However, in my mind there was one presentation that stood out above the others in terms of real hope for a particularly frustrating subset of lung cancer patients, namely those with EGFR activating mutations that develop resistance to Iressa (gefitinib) or Tarceva (erlotinib). The presentation was the initial results of a phase II trial combining afatinib (Tomtovok; BIBW 2992) with the anti-EGFR antibody cetuximab in TKI-resistant NSCLC patients.
This is a very frustrating group to treat. They tend to be younger, and most have never smoked or for only a short while, and they tend to respond wonderfully to TKIs like Tarceva. However, most patients will eventually go on to progress despite the TKI, and the reasons behind this progression have been a very active area of research. We know that about 50% of them, for example, will develop a second EGFR mutation in exon 20 called the T790M mutation.
There have been a number of strategies tested to overcome this resistance. The two major strategies have been to use a better TKI, such as the irreversible inhibitors BIBW 2992 and HKI 272, or to add a second drug to the TKI that inhibits a parallel pathway. One example of this strategy is the trial testing the addition of a MET inhibitor (ARQ 197) to Tarceva, which is now open all over the globe.
However, to date none of these strategies have proven to be particularly effective. One disappointing example was the LUX LUNG 1 study, which randomized patients who had failed chemotherapy and then progressed after benefit from a first-generation TKI (enriching the group for EGFR mutant cancers) to either afatinib or placebo. The goal of this study was to test if the irreversible TKI (afatinib) could overcome resistance by itself. Unfortunately, this trial failed to show a survival benefit from afatinib over placebo as a single agent. There were also only 7.4% of TKI-resistant patients who responded to afatinib.
Amrubicin for SCLC: Recap from ASCO
Though there are many presentations to discuss in the wake of ASCO, we’ll need to pace ourselves on these. I and some of the other faculty members will offer thoughts on some of these in the coming weeks, and we also have our upcoming post-ASCO review on June 23rd (click here to learn more and sign up for this free online program).
Today we saw the results of a couple of long-awaited trials of treatment approaches that represented a couple of the more promising concepts for moving forward in our treatment of extensive SCLC, and I’ll cover the first of these today (though only with the benefit of my notes, rather than as many details as I’d like, so these comments are subject to revision and added details later). Amrubicin has been the subject of some prior discussion here, but that discussion focused on smaller, phase II trials; we’ve needed the results of a randomized phase III trial that directly compares the chemo agent amrubicin as a single agent to our current standard for Hycamtin (topotecan). The ACT-1 trial in enrolled 637 patients with extensive disease SCLC who had all received first line therapy and then relapsed — the trial included patients who had a “sensitive” relapse, 3 or more months after prior chemo had ended, as well as “resistant” relapse, which is marked by progression within 3 months of prior chemo ending (pretty evenly split at nearly 50/50 on the trial). Patients were randomized 2:1 to either amrubicin at 40 mg/m2 IV on days 1-3 of a 21 day cycle, or topotecan at 1.5 mg/m2 IV days 1-5 of a 21 day cycle.
Quick Update from ASCO
I apologize if it seems that the updates about ASCO have been slow in coming. This is mostly because the lung cancer program this year has most of the higher profile presentations occurring in the second half of the meeting, which we’re just getting into. And, truth be told, this isn’t going to be a blockbuster year for developments in lung cancer. But let’s review what we’ve found out about thus far.
Balancing Risks of Undertreatment vs. Overtreatment of Locally Advanced NSCLC
Our multidisciplinary thoracic oncology tumor board is dynamic and a highlight of the week, facilitated in equal parts by the fact that our group genuinely enjoys each other’s company and that it is the source of some engaging debate about the potential best way to manage several complex scenarios in lung cancer. There are a few that have become recurring debates, among them the question of whether to pursue surgery for a patient with a locally advanced NSCLC, perhaps felt to be unresectable or on the outer limits of resectability, who has undergone chemotherapy and concurrent radiation to a potentially curative dose, has encouraging but ambiguous imaging findings, and is now being considered for surgery. Essentially, this is a troubling struggle of trying to balance our concern for over-treating vs. potentially under-treating this patient.
Interview with Dr. Tony Mok, Part 2
Continued from part 1
Dr. West: You have a huge portion of your patients who have an EGFR mutation and we know that over time patients develop acquired resistance. So how do you approach the patients who have a great response initially, have a known EGFR mutation, and then you see that slipping away at slow progression? Do you continue the EGFR inhibitor? Do you add something to it? Do you change the dose? How do you approach that?
Dr. Mok: I think this is one area where we still have a lot to learn. First of all, let’s define resistance, or progression. If you use the Jackman criteria (Jackman, J Clin Oncol 2010), that still incorporates the RECIST criteria, which mean if the lesion that has increased by about 30%, then it’s progression. But then one factor we didn’t look into was in the rate of progression within this definition. The second concern is about the occurrence of a new lesion that’s also progression. Now, whether this is directly applicable to a targeted like Tarceva or another EGFR TKI or not, I have some doubts, because simply from your experience and my experience, some of these patients get a new nodule, but they can take a long time to grow and the patient lives a normal life. And we also know the fact that if we take them off the TKI, the disease can progress rapidly. So some of these are slow progressors, then we just keep them on a TKI. Continue reading
Interview with IPASS Trial & Leading Lung Cancer Researcher Tony Mok
A few weeks ago I had the chance to speak with Dr. Tony Mok, who is a professor in the Department of Clinical Oncology at the Prince of Wales Hospital in Hong Kong and the Chairman of the Hong Kong Cancer Therapy Society.
He is also the principal investigator and lead author for the pivotal Iressa Pan ASian Study (IPASS), which was published in the New England Journal of Medicine in the fall of 2009. I started by telling him that I consider that study to be arguably the most influential over the last 5-10 years in the field of lung cancer, because it highlighted that molecular predictive factors trump clinical markers in determining who is likely to do best with a targeted therapy, specifically an EGFR tyrosine kinase inhibitor like Iressa (gefitinib) or Tarceva (erlotinib). Here’s the first part of our conversation about what we’ve learned about how best to use these EGFR inhibitors and the potential differences in practice between Asia and the US.
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