Adjuvant chemo has become increasingly established as having a survival advantage, at least for the general population of stage II and IIIA patients, and potentially for some with earlier stage disease (see adjuvant chemo post). However, post-operative radiation therapy, or PORT, does not have an established role. While historically there has not a clear advantage from PORT for patients with N1 nodal disease, for those with N2 nodes there has been a consistent improvement at least in local control and now emerging evidence of an survival benefit from PORT (see PORT post).
So for patients who undergo resection and had N2 nodes, there may be a benefit from both chemotherapy and radiation. One way to treat patients with N2 disease, if we know from a mediastinoscopy or another method that someone has N2 nodes involved prior to surgery, induction chemotherapy, or chemotherapy and radiation, are commonly used. In those cases, sometimes additional chemo is recommended after surgery, but not typically more radiation if it was given before surgery.
But there are also plenty of patients who either had unsuspected N2 disease until after surgery, or who undergo upfront surgery despite pre-operative staging showing N2 disease. Such patients were included on many of the trials testing the value of adjuvant chemo.
The problem of administering chemo and radiation after surgery is that it’s hard enough to take chemo after surgery, and adding another modality can escalate the challenge significantly. In the many clinical trials with cisplatin-based chemo after surgery, only approximately 70% of patients are able to get though the majority of planned chemo (carboplatin-based chemo is more feasible, with 85% of patients on the CALGB 9633 trial (initial positive 2004 abstract here, updated and now negative 2006 abstract here).
So when adding radiation to chemo, we need to balance the effectiveness with the safety and feasibility of what is now a tri-modality approach (surgery + chemo + radiation). In the ANITA trial that allowed radiation while testing the value of adjuvant chemo (abstract here), the patients who received both chemo and radiation did not receive them concurrently, but rather received chemo followed by radiation. Our experience with patients receiving chemo and radiation together for unresectable NSCLC has consistently demonstrated that concurrent chemoradiation is associated with a much higher likelihood of serious esophagitis, inflammation of the esophagus, that can limit the ability to eat and drink and make it very hard to continue treatment to completion.
One trial that is instructive about the challenges of administering chemo and concurrent radiation is the ECOG 3590 trial by Keller and colleagues (abstract here). In this trial designed to test the value of adjuvant chemotherapy for resected stage II and IIIA NSCLC, the investigators compromised by offering both arms PORT, and just one arm concurrent chemo with PORT, fearing that the arm not getting chemo would unwilling to be randomized to no treatment after surgery, so both arms received PORT, despite the fact that there was no established role for PORT. The schema is as shown:
In that trial, similar to the results on ANITA with N1 nodal disease, the combination of both modalities together did not provide any added benefit compared with one post-operative approach alone. Specifically, the results were essentially superimposable, and slightly better for radiation alone (median survival 39 months for PORT arm, 38 months for PORT/Chemo arm):
Only 65% of patients were able to even start all four of their intended chemo cycles — many patients found this aggressive approach too much to tolerate, even if they didn’t technically have enough side effects to be forced to stop (many patients refused to continue). There were considerably greater side effects with the combination, and a 1.6% risk of dying on treatment (1.2% with PORT alone).
So we have some evidence that chemo after surgery for N2 nodal disease is beneficial, and radiation after surgery for N2 nodal disease is also beneficial. The ANITA-1 trial suggests that both chemo and radiation given in a sequential way can provided greater benefits than just chemo. While the results of non-surgical stage III NSCLC show that concurrent chemo and radiation is generally more effective than sequential chemo and radiation, despite higher toxicity, but the older Keller trial suggests that giving chemo and radiation together after a very major lung surgery can be just too much for people to tolerate.
We don’t have a clear answer to the best way to combine all of these treatments for patients with resected N2 disease. SWOG is developing a trial now that will directly compare a concurrent approach (cisplatin/etoposide/RT to 50 Gy) followed by more chemo (taxotere) to a sequential post-op approach of chemo (4 cycles of cisplatin/taxotere) followed by PORT to 50 Gy.
This trial will plan to enroll approximately 120 patients over 1-2 years, and from there we can see if there is a clear winner. It will look at safety/feasibility as the primary endpoint, but it will obviously also be looking at survival as well.
Outside of a protocol, I and many of my colleagues tend to recommend sequential treatment in this setting after surgery, with N2 nodes involved. Specifically, with a more consistent survival benefit seen with adjuvant chemo, I generally recommend starting with chemo x 3-4 cycles, and then would recommend PORT if a patient is still up for more treatment that may add benefit — this is just what was done on the ANITA trial. But doing both together may be like juggling too many balls in the air at once, leading you to drop everything and not be able to complete planned chemo or radiation, and therefore potentially get less treatment benefit than just concentrating on one approach at a time. We need to balance the aggressiveness of these approaches against the feasibility of just getting through it all.
posted by Dr. West @ 5:19 pm link to this post





March 13th, 2007 at 11:16 am
Dr. West:
Concerning the trial ECOG 3590, there is no information in the abstract or in the slides that you provided about the distribution of the N1 and N2 patients in each arm, as well as specific survival for N2 patients.
Is it conceivable that the overall survival rate was not improved in the chemotherapy + PORT arm, but it was improved for the N2 patients in that arm? Since it looks like the N2 patients are the ones that seem to get the most advantage of PORT, I believe this is a natural question to ask.
On a related topic, I found an abstract of the final results of the Cancer and Leukemia Group B 9734 study of surgical resection and paclitaxel/carboplatin chemotherapy with or without adjuvant radiation therapy for IIIA patients.
The adjuvant radiotherapy in this case was administered after the chemo. Despite a difference in the median failure free survival (16.8 months on the observation arm and 33.7 in the RT arm) the authors of the study concluded that “consolidation RT after complete resection and adjuvant chemotherapy in stage IIIA NSCLC did not significantly improve outcome for this high-risk population”. This results surprised me, as it seems to contradict previous positive results of PORT after chemo for N2 patients.
Carlos
March 13th, 2007 at 8:03 pm
Carlos,
Thanks for that good addition to the subject by bringing up the CALGB trial. I had seen this article a couple of months ago but didn’t commit it to long-term memory because it was so small. I’ll write a brief addendum to my post tomorrow and include your catch, and I’ll add back the link to the abstract (sorry I took it out of your post, but it was so long that it completely wrecked the formatting for the page — not your fault; I can include the link without the long text in my addendum). Situations like this, where someone adds more information and points out my oversight, is a real benefit of the site for me. I try to cover a topic, but there are holes, and I’m glad to refine the thought process with input from other people. As the Japanese proverb goes, “none of us is as smart as all of us”.
I’ll review the article as soon as I can, but in the meantime, I’d say that it’s not really possible to take the conclusions very far because there were so few patients. That tells us that it will likely be hard to do larger trials and get firm answers. We’re probably catching more “occult” N2 nodal disease tan we used to, now that most patients get PET scans in their pre-operative staging routinely.
The problem with smaller studies is that you can find large differences between groups that are not statistically significant, which means that they can’t be ruled out as just happening by chance. You could flip a coin 4 out of 5 times just by chance, but you couldn’t do it 40 times out of 50. Larger trials make you more certain that the differences in probabilities are real. So seemingly large differences are still called “equivalent”. That’s not absolutely true: absence of proof isn’t proof of absence. The differences could proove to be meaningful if seen in larger samples. However, for the CALGB trial you mention, despite the difference in progression-free survival, the overall survival at one year was essentially the same. Median survivals (progression-free or overall) are not very meaningful in small samples, so overall I would say that this trial is too small to say anything definitive about how patients with N2 nodes should be managed. It isn’t big enough to counter the larger studies.
As for the breakdown by N1 vs N2 nodal status in the Keller trial, I didn’t mention it because there’s not much discussion of it, even in the full, final manuscript. The paper says that there were no significant differences in outcomes based on that variable, so it seems that the results were essentially the same for both groups as a function of N1/N2 status, but there’s no real data presented on that topic. I’ll mention that in my addendum as well, just to clarify the limits of the information available there.
-Dr. West
March 15th, 2007 at 9:32 pm
Dear Dr. West,
From the patient’s perspective it is very difficult not to opt for aggressive treatment especially if physically up to it.
Even if the nodes tested were OK there could be micro metastatic disease in untested nodes.
My radiation with chemo after surgery was an act of sheer desperation, but I’m still here 6.5 years later.
Barb
March 16th, 2007 at 11:26 am
Barb,
I would say that locally advanced NSCLC is the area of lung cancer where treatment needs to be individualized the most. Not only do we have a clearer sense of what “best” treatment is in the other lung cancer settings (NSCLC and SCLC) more than stage III NSCLC, but for stage III NSCLC we need to be as aggressive as we can be against a very threatening cancer, but we also need to balance that against the very real risk of serious or even fatal treatment-related toxicity (as high as 5-6% even in very well-run trials. So it makes sense to be aggressive if you can take it, but not if you save yourself from cancer but die from overly aggressive treatment.
I definitely think it’s appropriate to tailor the plans for the characteristics of the patient (health, mindset, etc.) and those of their tumor (how bulky, which nodes involved, how resistant to ongoing treatment). None of my conclusions should be seen as dogma. I don’t use them that way myself, but rather as principles to follow for the patient I’m working with.
-Dr. West