In early stages of cervical cancer, the main component of therapy is usually a so-called hysterectomy – an operation that removes part of the cervix or entire uterus. This can be done as a so-called abdominal hysterectomy, ie via an abdominal incision. An alternative are minimally invasive procedures, in which the uterus is either minced and sucked off (laparoscopically assisted supracervical hysterectomy) by small incisions in the abdominal wall (laparoscopy), or removed through the vagina. In the latter method, there are two options: To separate the uterus and cervix for removal from their suspending apparatus and blood vessels, the instruments are inserted either through the vagina (vaginal hysterectomy) or by abdominal laparoscopy (laparoscopically assisted hysterectomy).
Experiment stopped because of worse chances of survival
In two studies, researchers have now compared the chances of cervical cancer recovery after abdominal surgery with those after an open abdominal operation. Scientists at the MD Andersen Cancer Center in Houston evaluated data from more than 600 women who had surgery in clinics around the world. In half of the women the uterus was minimally invasively removed, in the other half by abdominal section.
"Patients who underwent minimal invasive surgery were four times more likely to relapse than those who had an open surgery," says study author Dr. med. Pedro Ramirez. A safety panel responsible for the study stopped the experiment when it became apparent that the women in the minimally-invasive group obviously had a distinct disadvantage. Four and a half years after the procedure, 94 percent of the patients in this group were still alive, and 99 percent of the women who operated on the open stomach were alive.
In a separate study, scientists from Northwestern University in Evanston, Illinois, came to a similar conclusion: in a national pool of cervical cancer patients, nine percent of women undergoing minimal invasive surgery had died after four years. Of the patients undergoing abdominal surgery, only five percent had died.
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Many questions are open
Why the minimally invasive procedure worsens the chances of recovery, can clarify neither of the two studies. The Houston researchers suggest that the carbon dioxide gas that guides the abdominal wall to the abdomen plays a role in raising the abdominal wall. There is evidence that this gas may affect the growth and spread of cancer cells.
Other puzzles point to the fact that the phenomenon does not seem to apply to all types of cancer: Previous studies suggest that minimally invasive hysterectomy is safe, for example, in tumors to the uterus, the authors emphasize. As the prognosis for patients in a purely vaginal hysterectomy, ie without abdominal cut, fails, is also not answered in the studies.
Raminez, P.T. et al. (2018): Minimally Invasive versus Abdominal Radical Hysterectomy for Cervical Cancer, in: The New England Journal of Medicine.
Melamed A. et al. (2018): Survival after Minimally Invasive Radical Hysterectomy for Early Stage Cervical Cancer, in: The New England Journal of Medicine.