FOR MORE THAN A QUARTER CENTURY, the standard-of-care treatment for patients with certain stage I non-small cell lung cancers (NSCLCs) has been lobectomy, a surgery that removes an entire lobe of the lung along with the tumor. However, a study published Feb. 9, 2023, in the New England Journal of Medicine (NEJM) suggests a procedure known as sublobar resection, which just removes the tumor and the surrounding tissue, may provide equal benefit to patients.
The phase III trial, conducted at hospitals in the U.S., Canada and Australia, recruited patients with early-stage NSCLCs whose tumors were 2 centimeters or less in diameter and were peripheral—located within the outermost third of the lung closest to the chest wall. Researchers randomized 697 participants to receive either a lobectomy or a sublobar resection. Similar portions of both groups—80.3% of patients after sublobar resection and 78.9% of patients after lobectomy—were alive five years after surgery. The two groups also had comparable rates of cancer recurrence.
“This is a pretty landmark trial,” says Seth Krantz, a thoracic surgeon at NorthShore University Health System in Evanston, Illinois, who was not involved in the study. “It can significantly change the way we treat early-stage lung cancer.”
If the lung is like a tree, a lobectomy is like removing a major limb, while a sublobar resection is like snipping off a small branch, Krantz says. The right lung has three lobes, while the left lung has two, so a lobectomy takes out one-third or half of a lung.
Lobectomy has been the standard-of-care treatment for lung cancers that are small in size and have not spread to the lymph nodes since 1995. At that time, a clinical trial comparing lobectomies and sublobar resections for these cancers showed patients who received sublobar resections were three times as likely to have a local cancer recurrence than those who had lobectomies, Krantz says. However, many participants in that trial, who were thought to have stage I cancer, likely had cancer that had already spread beyond the lung, according to Krantz. Today’s lung cancer staging is more accurate, which could explain why the results of the present study are so different.
“For a long time, we had thought that taking less [lung] was a really compromised operation, that we were doing a disservice to the patient in terms of their ability to cure the cancer,” Krantz says. Doctors would reserve sublobar resections for patients who already had compromised lung function.
The recently published trial results change that. “Now for really small cancers on the edge of the lung, we don’t have to take out nearly as much lung,” Krantz says.
The study confirms the findings of a phase III trial conducted in Japan where patients with stage I NSCLC received either lobectomy or segmentectomy, a type of sublobar resection. After a median follow-up of 7.3 years, there was no difference in overall or relapse-free survival between the two groups, according to results published April 23, 2022, in the Lancet.
“These two landmark trials are practice-changing because they establish sublobar resection as the standard of care for a select group of patients with NSCLC,” Valerie Rusch, a thoracic surgeon at Memorial Sloan Kettering Cancer Center in New York City, wrote in an editorial published alongside the NEJM study.
For some patients, having a sublobar resection instead of a lobectomy likely means an easier recovery and preservation of more lung function following surgery, Krantz says. However, since the NEJM study did not measure patient-reported outcomes, it’s not possible to draw any conclusions about the participants’ recoveries, he adds.
Six months following surgery, the group that had sublobar resections performed slightly better than the lobectomy group on a measurement of how much air they could expel quickly from their lungs after taking a deep breath. However, the difference was not clinically meaningful, says Nasser Altorki, a thoracic surgeon at Weill Cornell Medicine in New York City and lead author of the study. “You would think if you took less lung, you would have more lung function preserved, but that wasn’t the case, which is kind of curious, and we need to investigate that further,” he says.
Another reason to preserve lung tissue is that patients who have lung cancer once are likely to have another cancer in the lung, Altorki says. “If they’ve lost a lot of their lungs, their options for treatment of a future cancer, if it should occur, are limited,” he says. Patients may not be able to have two lobectomies and retain sufficient lung function. In contrast, a patient who’s had a sublobar resection could potentially have another sublobar resection or a lobectomy to treat a second cancer, Altorki adds.
Currently, about 32% of patients with NSCLC are diagnosed when tumors are isolated to the lungs, according to a report published March 2023 in Clinical Lung Cancer. Of these patients, a substantial proportion have the small, peripheral tumors that now make them candidates for sublobar resection, and as lung cancer screening tools improve, that proportion will only grow, Altorki says.
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