In cervical cancer surgery, minimally invasive is worse than open, study says
Posted October 31, 2018 5:00 p.m. EDT
(CNN) — The type of surgery a woman has will affect her ability to survive cervical cancer, new research suggests. Among patients with early-stage cervical cancer, women who undergo minimally invasive operations have a greater risk of dying than those who undergo open surgeries, two studies published Wednesday in the New England Journal of Medicine found.
The studies compared the same operation, radical hysterectomy, performed both as open surgery and as a minimally invasive procedure.
Radical hysterectomy, or removal of the uterus, cervix and other parts of the female reproductive system, is a recommended treatment for many patients with early-stage cervical cancer. Introduced in 1992, minimally invasive radical hysterectomy -- in which smaller incisions are made with either a laparoscopic or a robot-assisted procedure -- increased in popularity over time. Today, about 40% of cervical cancer hysterectomies are minimally invasive, according to Brigham and Women's Hospital.
Small studies of minimally invasive radical hysterectomy had "shown that it was safe," though most "just focused on what happened in the short term," explained Dr. Jose Alejandro Rauh-Hain, senior author of one of the new studies and an assistant professor of gynecologic oncology and reproductive medicine at the University of Texas MD Anderson Cancer Center in Houston.
His new analysis of information from the National Cancer Database included "a large sample of patients" and "looked at what happened many years after their diagnosis."
Survival rate differences by type of surgery
Of 2,461 patients who had a radical hysterectomy for early-stage cervical cancer, about half underwent minimally invasive procedures, and the remaining women had open surgery, Rauh-Hain and his colleagues found. Of the minimally invasive group, 94 women died in the four years after surgery; 70 women in the open surgery group did not survive four years, the study showed.
This translates to a 9.1% risk of death for women in the minimally invasive group and a 5.3% risk of death in the open surgery group, the researchers wrote.
Rauh-Hain and his colleagues also analyzed information from a separate national cancer database and found a stable four-year survival rate for early-stage cervical cancer prior to 2006. However, after that -- the time when minimally invasive radical hysterectomies grew more commonplace -- survival rates steadily dropped by about 0.8% per year. This trend suggests a cause and effect relationship between minimally invasive procedures and lower survival rates, according to the authors.
Cancer recurrence differences by type of surgery
A second new study also compared minimally invasive and open surgery procedures and found similar results. Here, patients with early-stage cervical cancer were randomly assigned to receive either a minimally invasive radical hysterectomy or an open radical hysterectomy.
"What we found in this study was that patients with early cervical cancer who underwent either laparoscopic or robotic radical hysterectomy had a higher risk of cancer recurrence, or cancer coming back," said Dr. Pedro Ramirez, lead author of the study and a professor and director of minimally invasive surgical research and education in the Department of Gynecologic Oncology at the University of Texas MD Anderson Cancer Center in Houston.
Overall, women who underwent a minimally invasive radical hysterectomy were four times more likely to experience recurrent cervical cancer than women undergoing open surgery, he said. And minimally invasive surgery was associated with a lower overall survival rate at three years: Nearly 94% survived, versus 99% of the open surgery patients.
So what's a cervical cancer patient to do if she has undergone a minimally invasive radical hysterectomy?
According to Ramirez, she should have a discussion with her physician about the research results and focus on when she is "at highest risk for recurrence." He noted that most of the patients in his study who had a cancer recurrence saw their cancer return within two years.
Patients who had minimally invasive surgeries more than two years ago should feel "reassured" because "most likely, they are going to be OK," he said.
Other patients, those whose minimally invasive operations occurred within the past two years, should discuss the studies with their physicians and be aware of "signs of recurrent disease -- signs such as vaginal bleeding, abdominal bloating, unexpected pain and persistent pain," Ramirez said. These patients should also talk about a plan for closer surveillance with their doctors, he said.
A 'strong message' about surgery
Rauh-Hain agrees that patients should discuss the studies and a comprehensive monitoring plan with their physicians.
Because results from both studies are "very, very similar," they deliver "a strong message that, in fact, minimally invasive surgery is not a safe approach among patients with early-stage cervical cancer," he said. "We really don't know at this point why patients with minimally invasive surgery had worse survival."
Though neither study was designed to answer that question, Ramirez said that having balanced the risk factors between the two groups of patients in his study, the only difference was the actual surgical approach. So what is unique about minimally invasive surgery that could increase the risk of cancer recurrence?
One factor is that surgeons "insufflate" or blow carbon dioxide gas into the abdominal cavity -- inflate it, essentially -- in order to see and work better. Animal studies have suggested that carbon dioxide may increase the ability of cancer cells to implant within the abdominal or pelvic lining, Ramirez said. He added that the manipulator, a tool used during these procedures, could also play a role in "spreading those cancer cells throughout the pelvis and the abdomen as well."
Ultimately, the study results were "a surprise," Ramirez said, adding he had not expected to send a "shock wave" through the field of gynecologic oncology.
Shock delivered, surgeons and physicians responded.
What patients can do
"When we learned about this study at our annual gynecologic oncology convention in March, we immediately evaluated our data to make sure we were not harming patients," said Dr. Walter Henri Gotlieb, a professor in the Department of Obstetrics and Gynecology at McGill University in Montreal.
Yet the evaluation at his particular cancer center showed no differences in survival between patients who had undergone open surgery and those who had undergone minimally invasive procedures, said Gotlieb, who was not involved in either study.
"Our findings have been written up, accepted for publication and will be published shortly in the Canadian Journal of Ob-Gyn," said Gotlieb, who noted that each cancer center could do the same evaluation of their own data.
Of the new studies, he said, "This is important work that was well-done, and we all need to take the information seriously, but it is obtained from cancer registries that contain many confounders." (Confounders are factors that might distort the results.)
He also wonders why other studies, including his own, show equivalence between open surgery and minimally invasive procedures.
"Many questions and controversies remain," he said. If there are differences in study outcomes, causality has not been established, and "further investigations are essential to understand what is going on," he said, noting that the authors of the two studies draw a similar conclusion.
Dr. Otis Brawley, chief medical and scientific officer of the American Cancer Society, said the design of both studies is "fine." Still, each contains an unintended bias or systematic error, said Brawley, who was not involved in either study. That error is "that you've got doctors who are not comfortable doing the operation" making up a large proportion of the surgeons in the studies.
Surgeons are individuals with unique track records
"I'd love to do a study where you look at individual doctors and you look at individual doctor's outcomes," Brawley said. In such studies, he believes, you'd find that some doctors using "the scope and robotic techniques" have really great outcomes while others do not.
Some tactile sensations are lost when operating using a robot, and many surgeons have not adjusted to that, which can be a difficulty, he said.
Robotic and laparoscopic surgery is growing so fast that educators are worried there are not enough surgeons who know how to operate traditionally, Brawley said. "Traditional surgery is needed in some patients who have a history of bowel obstruction or other complications," he said.
The takeaway for patients is to "find a surgeon you trust" and go with the method he or she recommends, he said. He would tell patients to look their doctors in the eye and ask whether they feel comfortable using the scope or using the robot.
"If you trust that doctor and that doctor feels comfortable using the scope or the robot, my gut feeling is, it's OK to get that surgery done with the scope or the robot with that particular doctor," Brawley said.
About 13,240 women will be diagnosed with cervical cancer in the United States this year, according to the American Cancer Society.
Gotlieb emphasized that "survival expectations are above 90%" for both groups of cervical cancer patients in the two studies, those who had minimally invasive operations and those who had open surgery.
"It is clear that dealing with a cancer diagnosis is a serious challenge in life," Gotlieb said. "Each person finds their own resources and strengths on how to manage life after the diagnosis."