WASHINGTON – Minimally invasive surgery – whether robotic or laparoscopic – is just as effective as open surgery in pancreatectomy.
Both minimally invasive approaches had perioperative and oncologic outcomes that were similar to open approaches, as well as to each other,, reported at the annual clinical congress of the American College of Surgeons. And while minimally invasive surgery (MIS) techniques were associated with a slightly faster move to neoadjuvant chemotherapy, survival outcomes in all three surgical approaches were similar.
Dr. Mirkin, a surgery resident at Penn State Milton S. Hershey Medical Center, Hershey, Pa., plumbed thefor patients with stage I-III pancreatic cancer who were treated by surgical resection from 2010 to 2012. Her cohort comprised 9,047 patients; of these, 7,924 were treated with open surgery, 992 with laparoscopic surgery, and 131 with robotic surgery. She examined a number of factors including lymph node harvest and surgical margins, length of stay and time to adjuvant chemotherapy, and survival.
Patients who had MIS were older (67 vs. 66 years) and more often treated at an academic center, but otherwise there were no significant baseline differences.
Dr. Mirkin first compared the open surgeries with MIS. There were no significant associations with surgical approach and cancer stage. However, distal resections were significantly more likely to be dealt with by MIS, and Whipple procedures by open approaches. There were also more open than MIS total resections.
MIS was more likely to conclude with negative surgical margins (79% vs. 75%), and open surgery more likely to end with positive margins (22% vs. 19%).
Perioperative outcomes favored MIS approaches for all types of surgery, with a mean overall stay of 9.5 days vs. 11.3 days for open surgery. The mean length of stay for a distal resection was 7 days for MIS vs. 8 for open. For a Whipple procedure, the mean stay was 10.7 vs. 11.9 days. For a total resection, it was 10 vs. 11.8 days.
MIS was also associated with a significantly shorter time to the initiation of adjuvant chemotherapy overall (56 vs. 59 days). For a Whipple, time to chemotherapy was 58 vs. 60 days, respectively. For a distal resection, it was 52 vs. 56 days, and for a total resection, 52 vs. 58 days.
Neither approach offered a survival benefit over the other, Dr. Mirkin noted. For stage I cancers, less than 50% of MIS patients and less than 25% of open patients were alive by 50 months. For those with stage II tumors, less than 25% of each group was alive by 40 months. For stage III tumors, the 40-month survival rates were about 10% for MIS patients and 15% for open patients.
Dr. Mirkin then examined perioperative, oncologic, and survival outcomes among those who underwent laparoscopic and robotic surgeries. There were no demographic differences between these groups.
Oncologic outcomes were almost identical with regard to the number of positive regional nodes harvested (six), and surgical margins. Nodes were negative in 82% of robotic cases vs. 78% of laparoscopic cases and positive in 17.6% of robotic cases and 19.4% of laparoscopic cases.
Length of stay was significantly shorter for a laparoscopic approach overall (10 vs. 9.4 days) and particularly in distal resection (7 vs. 10 days). However, there were no differences in length of stay in any other surgery type. Nor was there any difference in the time to neoadjuvant chemotherapy.
Survival outcomes were similar as well. For stage I cancers, 40-month survival was about 40% in the laparoscopic group and 25% in the robotic group. For stage II cancers, 40-month survival was about 15% and 25%, respectively. For stage III tumors, 20-month survival in the robotic group was near 0 and 25% in the laparoscopic group. By 40 months almost all patients were deceased.
A multivariate survival analysis controlled for age, sex, race, comorbidities, facility type and location, surgery type, surgical margins, pathologic stage, and systemic therapy. It found only one significant association: Patients with 12 or more lymph nodes harvested were 19% more likely to die than those with fewer than 12 nodes harvested.
Time to chemotherapy (longer or shorter than 57 days) did not significantly impact survival, Dr. Mirkin said.