In Japan, a different chemotherapy approach than cisplatin doublet chemo has been used in the post-operative setting. In contrast to the North American and European approach of 3-4 cycles of platinum-based chemo, in Japan they have studied an oral chemotherapy called UFT, a combination of uracil and tegafur. This combination is in the same family as an old chemo drug called 5-FU that is still used in various settings today, although not commonly in lung cancer. Nevertheless, this oral chemotherapy, which isn’t and probably won’t become available in the US and several other parts of the world, has been studied in a Japanese population and actually shown to improve survival in patients with stage I NSCLC. And this year we saw an analysis of the benefit of chemotherapy on the basis of patient age in this trial (abstract here).
The original trial enrolled just under 1000 patients with stage I adenocarcinomas (a remarkably common presentation in Japan, where they really do see a fundamentally different lung cancer biology than we see in North America and Europe, at least). This focus on patients with adeno NSCLC is based on earlier work that indicated this drug worked preferentially in adenocarcinoma tumors, and randomized patients with stage I tumors to observation or up to two years of daily oral chemotherapy after surgery (abstract here). As shown in the curves below, there was a modest but significant survival benefit, and nearly all of that benefit was seen in patients with larger, higher risk T2 cancers, rather than the smaller T1 cancers with the lowest risk for recurrence and death:
Interestingly, this is really the most conclusive survival benefit we’ve ever seen for stage I NSCLC, and in the curve for the overall trial population (left curve), the separation of the curves that signifies a survival benefit from treatment doesn’t occur until four years out. Unfortunately, this is with a drug not available in the US and was a benefit seen only in patients with stage IB adeno NSCLC: we haven’t been able to do another study with UFT to confirm this, but it’s currently a standard treatment in Japan.
One of the core ideas in the management of stage III, or locally advanced, NSCLC is that unresectable disease that is being treated with curative intent is most effectively treated with a combination of concurrent systemic (“whole body”) therapy and chest radiation to all of the visible cancer. The systemic therapy, which has been conventional chemotherapy, is given to both make the radiation work better and to treat potential micrometastatic disease, cancer cells in the bloodstream that can’t be reached by radiation but could potentially be killed off by a treatment that goes throughout the bloodstream.
The challenge, though, is that concurrent chemo and radiation is hard on people, with a rate of treatment-related deaths of about 5-7% of people even on clinical trials (which often select for a fitter population than are seen in the “real world” of many ineligible patients). So we reach a point where the aggressiveness of the treatment can be associated with problems that are as threatening or worse than the underlying disease. And this is a particular problem for older and/or frailer patients, which happens to cover a significant proportion of people with lung cancer.
Part of the promise of targeted therapies all along has been that they could potentially substitute for standard chemotherapy as a systemic therapy that is perhaps as effective as chemo but with fewer side effects. Most of our work with these agents has been to just add them to our current standards, but it still makes sense to consider using them as a substitute in patients for whom conventional chemo is really at the upper limits of what is tolerable. And it’s clear that doing chemo concurrent with radiation is overall more effective than doing them sequentially, but perhaps we could get the tolerability of a sequential approach with the efficacy of concurrent therapy by doing a program of targeted therapy (and no chemo) concurrent with chest radiation.
Despite the fact that a very significant proportion of the “real world” patients have considerable medical problems such as markedly decreased lung function (pretty common with many years of smoking), weight loss (5 or 10% of body weight is usually considered a problem), or otherwise are not able to be very active. The vast majority of clinical trials for potentially curative, combined modality (chemo and radiation) approaches of chemotherapy and radiation have often been restricted to patients with a good performance status (PS), which means that patients are either unrestricted in their activities or are symptomatic but able to perform light work activities. Chemoradiation approaches, and especially those that include concurrent chemotherapy and thoracic radiation therapy (RT), are generally accompanied by considerable acute side effects and a treatment related death rate in the 5-6% range even in quite fit patients. With such challenges even for the healthier patients, this precluded those with marginal PS at baseline from participating in more rigorous multimodality strategies. So how should we manage patients with a PS of 2, corresponding to an ability to care for themselves but unable to work? The short answer is, we don’t have enough information to say, but there are a few studies that have addressed this very under-studied population.
One early study that demonstrated the feasibility of an attenuated concurrent chemoradiation approach in marginal patients not able to safely receive standard platinum-based chemotherapy and radiation was SWOG 9429 (abstract here). This multicenter, single arm study (everyone received the same treatment) accrued 60 “poor risk” patients, defined as having a PS of 2 with low blood protein levels or >10% weight loss, insufficient lung function reserves for more aggressive combined therapy (measured by the amount of air someone can blow out of their lungs in one second, called the FEV-1, for forced expiratory volume), or medical problems that made it infeasible to give standard cisplatin (including hearing loss, kidney problems, congestive heart failure, or peripheral neuropathy). The treatment approach included a relatively low dose of carboplatin IV on days 1 and 3, along with etoposide the first four days of a 28-day cycle. Chemo was given for a total of two cycles concurrent with daily chest radiation to 61 Gray (Gy) — a full dose. This trial demonstrated feasibility of this approach, with moderate acute toxicity and no treatment-related deaths, as well as encouraging efficacy: the median overall survival of 13 months, and the two-year survival was 21%; these numbers are in the ballpark of results from trials with more vigorous patients. Probably significantly, the majority of enrolled patients had a good PS and compromised pulmonary function, with only 18% of enrolled patients having a PS of 2. Continue reading