We’ve covered the potential value of systemic therapy for early stage NSCLC in a wide range of posts and podcasts, and to summarize what we’ve learned in a sentence, it’s basically that chemotherapy can significantly increase progression-free survival (PFS) and overall survival (OS) in patients who have undergone curative surgery for stage I-III NSCLC, but the benefit is far more convincing in patients with a high enough risk to justify the potential adverse effects of chemotherapy. In fact, in patients with node-negative cancers that are smaller than about 4 cm, the evidence isn’t very good that chemotherapy improves outcomes, and there is a strong suggestion from the limited available evidence that it may be net harmful. This makes sense to me: chemotherapy represents a fixed negative effect (both quality of life and risk of adverse effects) whether a patient has a high risk of recurrence or a low risk of recurrence and can reduce the chance of the cancer recurring by a certain proportion. If the risk of recurrence is high (such as in someone with stage II or III resected NSCLC), chemo can reduce that risk quite a bit, so the net effect is very positive: big anticipated benefit exceeds small risk. However, in patients with smaller node-negative cancers, the magnitude of benefit is going to be very low because the risk of recurrence is too low for the chemo to have much absolute effect: small risk exceeds even smaller anticipated benefit.
In recent years, we have generally focused on post-operative, or adjuvant chemotherapy, because the majority of positive trials for early stage patients have used an adjuvant strategy. However, going back in time ten years, both pre-operative (neoadjuvant) and post-operative chemotherapy were investigational approaches, and they each have their advantages and disadvantages. Post-operative chemotherapy has the benefit of being able to make treatment recommendations based on the most accurate staging information (from surgery) and provides the opportunity to do the most pivotal treatment immediately, but many patients are simply not able to consider chemotherapy within the first couple of months after surgery, and/or they need to abort treatment before the intended therapy has been delivered. Pre-operative chemotherapy provides the earliest opportunity to treat potential micrometastic disease, should improve the probability that treatment will be delivered as planned (because few people will decide to abandon surgery), and it gives the chance to get feedback on how effectively the systemic therapy shrunk the cancer. However, it also entails a small but real chance that the person’s cancer will grow and even potentially no longer be able to be resected, and possibly that chemo could increase the risk of surgical and post-surgical complications. Pre-operative therapy may also have an advantage of allowing a patient to receive a less extensive surgery after a good response to initial systemic treatment.
So it’s fair to say that there is a good rationale to test both of these strategies, and studies have been pursued with surgery followed by randomization to chemo or observation, immediate randomization to chemotherapy followed by surgery or immediate surgery alone, and even one trial that randomized patients to pre-operative chemotherapy followed by surgery, surgery followed by chemotherapy, or neither pre-operative nor post-operative therapy and just surgery alone. By 2003 and 2004, several trials of post-operative chemotherapy were reported as positive, and this led to early closure of several of the important pre-operative chemotherapy trials, since the emerging picture was that chemotherapy provided a benefit that made randomization of patients to a surgery alone arm unethical.
It is in this context that we can now review the significance of the newly published Chemotherapy in Early Stages Trial (ChEST), which was conducted at 45 centers in 15 countries in Europe and attempted to assess the benefit of three cycles of cisplatin/gemcitabine before surgery, compared with surgery alone. The trial was designed with an intent to enroll 712 patients with stage IB to stage IIIA NSCLC (stage IIIA only if they had no mediastinal nodal involvement, so T3N1) and was looking to detect a 20% improvement in PFS as the primary endpoint, but from 2000 to 2004 only 270 patients were enrolled (129 randomized to pre-op chemotherapy, and 141 randomized to surgery alone). It closed early in light of the mounting evidence supporting a role for chemotherapy. Continue reading
We all know now that lung cancer, and in particular NSCLC, sits atop the list of cancer killers in the United States and western world. We also have been having extensive discussions on this site about all these great new treatment modalities: better staging (i.e. PET), better surgeries (i.e. VATS), radiosurgery (i.e. gamma knife), better radiation (i.e. IMRT), and better chemotherapy or targeted agents. But have all of these advancements done anything other than raise the cost of healthcare so much that Medicare is in danger of going broke paying for $100,000 Avastin-containing regimens?
In this month’s Journal of Thoracic Oncology, a group of cancer epidemiologists published a study looking at the survival of almost 11,000 patients with lung cancer over the 20 year period from 1985 to 2004, looking at the contributions of surgery, radiation, and chemotherapy and how the survival changed over that period. All of the patients were treated in Manitoba, Canada, so they can be considered to have received standard treatment for the time period and I think these patients can be compared to lung cancer patients anywhere in the developed world.
The first thing that jumped out from this study was that the rate of patients receiving surgery fell over time. Most people don’t realize that CT scans were not widely available in the early to mid-1980s, so many patients with metastatic (incurable) disease were going to the operating room when their chest x-rays incorrectly suggested they had curable disease. It makes perfect sense that fewer patients are having inappropriate surgery these days, now that staging is better in the CT and more recently the PET era.
The next interesting thing from this study, and the main point of this post, was that the authors found that overall survival in all NSCLC patients began to improve starting in 1997, and has been increasing by about 2 weeks every year between 1997 and 2004. Added together, this is about 3.5 months in improved survival over this period.
Not only did survival improve overall, it improved for early-stage patients receiving primary surgery, for locally advanced (stage III) patients getting chemotherapy and radiation, and for incurable patients treated with chemotherapy alone. The improvement in surgery is almost certainly because the staging has improved dramatically, so that only true early stage patients are getting surgery these days. Put another way, when large numbers of more advanced patients receive surgery but are not cured (because surgery does not cure stage 3 and 4 NSCLC by itself), the overall group looks like it has poor survival. So by only doing the surgery in the right patients, the overall group ends up having better survival.
The improvement in locally advanced and metastatic NSCLC survival also makes sense. Again, I doubt most people realize this today, but until 1995 there was no real evidence that chemotherapy helped anyone live longer with NSCLC. In 1995, a large meta-analysis of prior trials showed that platinum-based chemotherapy regimens did have an impact in lung cancer survival, and modern chemo began to be used much more often.
So many of you may be thinking that 3.5 months doesn’t seem like a big deal, but I would argue that it is a big deal. Keeping in mind that the average survival for patients with advanced lung cancer in 1997 was about 9 months, this represents a 39% improvement in survival in only 7 years!
I think one of the most encouraging things about this study is that this improvement in survival took place before the treatments that I mentioned above: before extensive use of IMRT or radiosurgery, before the common usage of targeted agents like Avastin or Tarceva, even before the common use of adjuvant chemotherapy after surgery, which began in 2004 and clearly is improving survival in early stage patients. I think there is a good chance that our most recent advances may actually be advancing the survival of patients at an even faster rate than described in this study.
I know that everyone secretly hopes for a dramatic cure of lung cancer. When new studies come out that show a 5 week or 2 month improvement in survival, there can be a collective yawn from the world at large. But I would argue that this is how it really works in the world of oncology, in incremental little advancements that build up over time. Colon cancer used to have an average survival very similar to lung cancer, but over 10-12 years the survival has more than doubled with the addition of several incremental advancements, each only adding 2-4 months but together helping move average survival from 10 months in the 1990s to >24 months today. It is my hope that NSCLC is well on its way!
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Ask and ye shall receive! The leading requiest for a video podcast presentation was for a summary of the subject of locally advanced, unresectable stage III NSCLC. Here you go:
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Sorry it’s a little rushed, but it’s a struggle to do a topic justice with a 10 minute limit (the most YouTube accepts). In the future, we’ll try to divide bigger topics into two podcasts if it’s going to require cramming into a 10 minute interval. It may help for you to have the images and transcript available, so here they are:
Locally Advanced NSCLC vodcast images