While the prevailing standard of care for resectable lung cancer is a lobectomy or pneumonectomy, we want the surgery to be as appropriate as possible for patients.  That means not short-changing patients by doing a lesser surgery than they need to do as well as possible with the cancer, but also not overtreating patients with a more aggressive surgery than they need.  There are two main variables that potentially alter the equation and may make a sublobar resection a more appropriate consideration.  The first is in cases in which the patient has competing risks of survival and/or medical problems that make a more aggressive surgery less necessary or more morbid (side effect-ridden, longer time for recovery, etc.) than average, or both.  The second situation is when the cancer has more favorable features than most, so even in healthier patients it may not be necessary to do a more extensive surgery.  I’ll explore the first scenario now.

   As I mentioned in a previous post introducing the different types of lung surgery, an influential trial by the now defunct Lung Cancer Study Group indicated that survival is superior in patients who receive a pneumonectomy or lobectomy compared to those who receive a segmentectomy or wedge resection (abstract here).  However, there was actually no difference in survival in the first three years, with improvement only emerging with longer follow-up.  This suggests that patients with competing health risks may not be as well served by a more aggressive surgery.  Thoracic surgeons have therefore asked whether elderly patients may do as well or better with a sub-lobar resection that involves less blood loss and recovery time without a significant compromise of cancer-related survival.  One important study suggest that’s the case.

   The study by Mery and colleagues from Brigham & Women’s Hospital in Boston (abstract here) was a retrospective review of the survival of over 14,000 patients in the Surveillance, Epidemiology, and End Results (SEER) database, a collection of information from cancer registries from all over the country, and covering about 14% of the US population.   These patients had all undergone surgery for stage I or stage II NSCLC.  The investigators divided patients in the database into three age groups: under 65, 65-74, and 75 and older.  Not surprisingly, survival was significantly better in younger patients than older patients, and the 17% of patients with stage II NSCLC had a significantly worse survival than patients with stage I NSCLC.  Overall, patients who underwent a pneumonectomy had a significantly worse survival than other patients, but it’s unclear whether this is due to the peri-operative mortality (deaths within 30 days of surgery, which are much higher after a pneumonectomy than a lobectomy), the loss of pulmonary capacity after surgery, or characteristics of the tumors that required a pneumonectomy (larger, more central).   Patients who underwent a wedge resection also had a lower survival overall than other patients.

   When evaluating the differences between different types of surgery as a function of age, however, it wasn’t the case that patients of all ages did better with lobectomies than “limited resections” (sub-lobar surgeries).  In fact, patients under 75 had a significant survival advantage after a lobectomy, but the patients 75 and older did every bit as well after a wedge resection or segmentectomy as they did after a lobectomy:

(Click to enlarge image)

They evaluated the age difference using a different cut-off of 71 years and found that patients 71 and younger had a significant benefit from lobectomy, while those older than 71 did not.  There was a modest separation of the curves after about two years even in older patients, but the difference in survival was not significant even with longer follow-up.

Despite sub-lobar resections not being considered the standard of care, older patients were more than twice as likely to have undergone this surgery than younger ones (17% vs. 8% of curative surgeries).

   This article leaves us with a few important conclusions.  First, it provides further corroborating evidence that younger patients have a superior survival with a lobectomy than a limited resection (at least the overall population).  Second, it suggests that the overal population of patients over 71 have an equivalent survival following a sub-lobar resection compared to a lobectomy.  This conclusion only applies, however, to older patients who have a complete resection with negative surgical margins. 

   This is not the final word on the issue, but these data come from a very large database and make sense to consider carefully in weighing the risks and benefits of a more aggressive vs. less aggressive surgery.  The age cutoff is not necessarily the gospel, but rather speaks to the idea that patients with competing health problems should have the risks of the cancer weighed against the risks of their other issues.  For some remarkably healthy patients with no competing health problems and an anticipated survival of many, many years, it may be very appropriate to pursue the most aggressive approaches against lung cancer. 

   Next, I’ll discuss the other issue of cancers that may be favorable enough that they don’t require as aggressive a surgery as most others, even in younger and healthier patients.