SAN DIEGO—Even when non-small-cell lung cancer (NSCLC) invades the pulmonary artery—often considered a contraindication for surgery—resection of the cancer plus reconstruction of the artery appears to be successful in most cases, researchers reported here at the Society of Thoracic Surgeons Annual Meeting.
“In reviewing our data, we can say that pulmonary artery reconstruction is a safe procedure,” said Domenico Galetta, MD, Senior Deputy Director of the Division of Thoracic Surgery at the European Institute of Oncology in Milan, in his oral presentation.
More than half of the patients with NSCLC who underwent the procedure were alive at five years, and for most of them their cancer had not recurred, he reported at the meeting, which had about 4,000 surgeons, clinicians, and other health care professionals in attendance.
“This operation is technically feasible, and it is oncologically effective,” Galetta said. “We had a low recurrence rate, and good long-term outcomes. Our results support this technique as an effective option for patients with non-small-cell lung cancer.”
He reported that 30-day mortality in the series of 150 patients was 3.3 percent—two patients died due to broncho-vascular fistula; two from acute respiratory distress syndrome, and one patient of a stroke.
A total of 59 patients had recurrences, including 14 with locoregional recurrences.
About 30 percent of patients had postoperative complications. Of these 46 patients, pulmonary complaints occurred in 33—most commonly prolonged air leak, and 28 had cardiac complications, almost all involving arrhythmias.
In terms of the histologies, 32.7 percent of the patients were diagnosed with squamous cell carcinoma; 46 percent with adenocarcinoma; and the remaining 21.3 percent had various mixed forms of NSCLC.
The overall survival rates were 50.4 percent at five years and a projected 39.6 percent at 10 years; 49.1 percent of patients remained disease-free at five years.
Galetta said that patients with adenocarcinoma fared better, with a five-year survival rate of 64.3 percent compared with 33.3 percent for patients with squamous cell cancer and 35.4 percent for patients with other NSCLC histologies.
Half the patients had undergone neoadjuvant therapy prior to surgery. However, a complete response was observed in just seven of these 75 patients—7.6 percent of patients, Galetta said. “There was no difference in long-term outcome between patients who received induction chemotherapy and those who did not.”
At five years, the overall survival rate of patients who received induction chemotherapy was 56.2 percent, compared with 44 percent for the patients who were not treated with anti-cancer therapies before surgery.
As expected, he said, the stage of disease at diagnosis made a difference—about 66 percent of patients diagnosed with T1 or T2 disease were alive at five years compared with 32 percent of patients diagnosed with Stage III disease.
About eight percent of patients were diagnosed with Stage 1A NSCLC; 13 percent with Stage 1B; five percent with Stage IIA; 24 percent with Stage IIB; 34 percent with Stage IIIA; and 11 percent with Stage IIIB cancer.
Similarly, he reported, nodal status also made a difference: About 61 percent of patients with N0-N1 disease survived at least five years compared with 28 percent of patients diagnosed with N2 disease.
First Reported in 1954
Galetta explained that pulmonary artery reconstruction was first reported in the medical literature in 1954. Several additional studies of the problem in conjunction with lung cancer resection have appeared since then, but the largest number of patients in any of the previous studies was 105. This new study of 150 patients, therefore, appears to be the largest one reported.
In the previous studies, morbidity ranged from about six to 29 percent; mortality from one to 17 percent; and five-year survival was 24 to 60 percent. He and his colleagues reviewed the outcomes in performing the surgery among patients treated from 1998 to 2013. All patients had NSCLC that had either infiltrated the pulmonary artery or had satellite lymph nodes that had infiltrated the artery.
The co-moderator of the session at which the study was presented, Leah Backhus, MD, MPH, Assistant Professor of Surgery in the Division of Cardiothoracic Surgery at the University of Washington Medicine and Chief of Thoracic Surgery at the VA Puget Sound, said: “Even today there are people who won't operate on these patients because they are either unfamiliar with or not confident in the techniques required to do these procedures.
“I would attempt to patch the pulmonary artery in patients up to Stage IIIA,” she told OT. “I think Stage IIIB is too advanced to attempt this procedure. Most people would not operate for Stage IIIB non-small-cell lung cancer.
“The 30-day mortality of 3.3 percent is a bit higher than we normally see—it is usually around one percent—but this group is doing radical stuff. These procedures are being performed regularly, but they are not being done by everyone. The point Dr. Galetta and his colleagues are making is that you can and should resect these patients. Still, it would be a bad take-home message that the Stage IIIB patients should be resected in these situations.”
Types of Procedures
Galetta said that in performing the reconstruction, surgeons employed a running suture method, patch reconstruction, or conduit interposition depending upon the extent of the infiltration into the artery. The invasion of the pulmonary artery occurred on the left side of 72 percent of the patients in the study, he noted.
Almost all the patients required a partial reconstruction of the pulmonary artery—146 of the 150 patients. The remaining four had circumferential repair of the artery. In 113 of the repairs, surgeons employed a running suture technique; in 22 percent, a pericardial patch was used—in 21 of these 33 cases the patch was autologous, and in the remaining 12 cases surgeons used heterologous patches. In four cases a conduit was created to allow for arterial flow. In these cases, reconstruction was made using a polytetrafluoroethylene graft in two patients, and a custom-made bovine pericardial conduit was created for use in the other two.
Autologous vs. Bovine
In response to questions from the audience, Galetta said that in his group's experience there did not seem to be any differences in outcomes or in procedures if the patch was autologous or bovine material.
The extent of the operation—whether the surgery involved just the pulmonary artery or the pulmonary artery and the bronchus—did not appear to affect the outcomes, Galetta added. The five-year survival rate among patients who had just pulmonary artery surgery was 49 percent, versus 42.5 percent for patients requiring surgery that included the bronchus.
He reported that bronchial sleeve resection was accomplished in 56 cases, and in six cases, superior vena cava reconstruction was also required.