With the median age of patients now being diagnosed with lung cancer in the US a little over 70, the question of how best to manage elderly patients with lung cancer is a very relevant but also understudied question. One central debate we often have when considering treatment options for elderly patients who present with smaller early stage lung tumors is whether they should undergo a wedge resection (removes just the tumor itself with a rim of non-cancerous lung tissue around it), a segmentectomy (removal of just a segment of the lobe in which the cancer is contained), or a full lobectomy, the more extensive surgery that removes the entire lobe around the cancer, along with a careful dissection and removal of many lymph nodes (more discussion of these options in this podcast by thoracic surgeon Eric Vallières). A lobectomy is more rigorous and a better operation for the cancer, but if patients have competing medical problems, perhaps a less extensive surgical procedure, a “sub-lobectomy” will do the job well enough and reduce the risk of complications.
Historically, there hasn’t been a lot of evidence to speak directly to this question. In our thoracic oncology tumor boards, we often rely on the results of the report by Dr. Mery and colleagues that reviewed the results in a large database and showed that elderly patients who received a sub-lobectomy seemed to do just as well as elderly patients who received a lobectomy. That’s a retrospective review of a large database, so it would certainly be helpful to add to this discussion. Fortunately, some new information is emerging to help shed further light on the matter.
In a paper just published in the Annals of Thoracic Surgery, Okami and colleagues from Osaka, Japan reviewed outcomes for 764 patients who underwent either a lobectomy or sublobectomy for a stage IA NSCLC tumor between 1990 and 2007. They separated their results by age group, either elderly (defined as 75 or older) or younger. This yielded 133 elderly patients, of whom 79 underwent a lobectomy and 54 underwent sublobar resection, and 631 younger patients (539 lobectomies, 92 sub-lobectomies).
What they found was that there was a striking difference in outcomes in the younger patients; with a 5-year survival of 90.9% and 64.9% (p < 0.0001) for lobectomy and sub-lobectomy recipients, respectively. However, in elderly patients, there was no difference: 5-year survival was 74.3% and 67.6% (p = 0.92) for the lobectomy and sublobectomy groups, respectively. These differences are shown in the figures below, in which the top panel shows the survival differences for lobectomy vs. sub-lobectomy for all patients, the middle panel shows patients under 75, and the bottom panel separates out those patients 75 or older:
Both age groups experienced significantly higher rates of loco-regional recurrence after a sub-lobectomy, about 11-12% vs. ~1.5% for each group. Finally, the authors noted that there were no real differences in complications for elderly patients who underwent the more or less extensive surgery.
You could conclude that a sub-lobectomy is a very clearly inferior surgery for younger patients, with a trend toward the same conclusion in the elderly, but it’s very important to recognize that this was a retrospective study in which patients generally underwent a sub-lobectomy because their heart or lung function was too poor to tolerate a lobectomy. We should expect to find that in non-randomized studies of a more vs. less aggressive approach, those who were selected for the lesser treatment do far worse, but this in large part because of the other issues that required them to pursue the less intensive strategy. This should also lead us to suspect that the elderly patients who underwent sub-lobectomy were often less healthy than those who underwent a lobectomy, so the fact that they did relatively similarly speaks well for the sub-lobectomy strategy if it produces even comparable survival results.
At the same time, it’s worth noting that the cancers seen in Japan, especially the small stage IA NSCLC cancers, are not necessarily the same as those seen in other parts of the world. In fact, the overwhelming majority in this study were adenocarcinomas, and half of the patients were never-smokers. Though there isn’t mention of a subset of patients with bronchioloalveolar carcinoma (BAC), we might well presume that many of these adenocarcinomas were BAC lesions that are known to have an especially favorable long term survival when they’re small. This may also be a reason why the survival for younger patients with stage IA NSCLC tumors who underwent lobectomy, at over 90%, is so exceptionally high. This is likely a somewhat different population of patients and cancers than you’d see outside of Asia.
Still, even with the limitations we have here, these data suggest that older patients for whom you have reason to be concerned about their ability to tolerate a full lobectomy surgery can do comparably well with a wedge resection or segmentectomy.
We’ll continue with discussion of another publication and an associated commentary in the next post.