(Reuters Health) - Women with early cervical cancer who opt for minimally-invasive surgery die sooner and are more likely to have their tumors reappear than those who have a conventional hysterectomy, according to two studies that could dramatically change treatment for the deadly malignancy.

Minimally-invasive laparoscopic surgery involves using just three or four small incisions in the abdomen to remove the uterus. Recovery time is much faster than with traditional “open” surgery, which involves a single large incision.

“You have a four-times greater likelihood of recurrence” with the less-invasive technique, whether or not a robot is used in the operation, said Dr. Pedro Ramirez of the University of Texas MD Anderson Cancer Center in Houston, who led a randomized comparison of the procedures published in the New England Journal of Medicine.

A second study in the same issue reviewed data on nearly 2,500 women and found the risk of death from any cause over up to four years was 65 percent higher with the less-invasive operation.

The reason less-invasive surgery is less safe remains a mystery.

The Ramirez study “was never designed to determine what the cause of this inferiority is because we didn’t think there would be an inferiority,” Ramirez told Reuters Health in a phone interview.

Similar less-invasive surgery is used to treat endometrial, ovarian and uterine cancers, but for those malignancies, studies have shown that minimally-invasive surgery does not pose a higher risk of complications, death or tumor recurrence, noted Dr. Jason Wright, chief of gynecologic oncology at Columbia University Irving Medical Center and New York-Presbyterian Hospital in New York City and a coauthor of the second study.

So with cervical cancer, Wright said in a phone interview, “this is definitely not what we expected to find.”

Cervical cancer strikes about 13,200 women in the U.S. each year and nearly 4,200 die from it annually, according to the American Cancer Society.

The new findings could mean that very few women will opt for minimally-invasive surgery for this type of cancer, even though it has become increasingly popular since 2006, the doctors said.

MD Anderson has stopped using it for early-stage disease since the new study uncovered the higher recurrence rate, Ramirez noted. So have other medical centers that learned of the results, beginning at a medical meeting in March.

Before minimally-invasive treatment became widely adopted, survival times for women with cervical cancer were improving. Embracing minimally-invasive surgery reversed that trend “and coincided with the beginning of a decline in the 4-year survival rate of 0.8 percent per year between 2006 and 2010,” Wright’s team reports in their paper.

In an interesting twist, Wright’s team found that women who were not white, not privately insured and lived in areas with lower average incomes and lower education levels were more likely to have undergone “open” surgery, with its longer recovery time, greater risk of blood loss and other drawbacks. Yet those women were more likely to survive. Socioeconomic factors are often tied to treatment success.

If anything, “we should have expected the patients who had open surgery to do worse, and that clearly wasn’t the case,” Wright said. “The bias should have been the other way in this study, which was another surprising factor.”

However, Dr. Otis Brawley, chief medical officer of the American Cancer Society, expressed skepticism in a telephone interview, saying he suspects that middle- and upper-class women might be more likely to push for the less-invasive surgery with doctors who are less comfortable with it.

“If you find the doctor who is comfortable doing the laparoscopic procedure, I think the outcomes would be just as good as with open surgery,” he said.

The women in the two studies had stages IA2 and IB1 cervical cancer, meaning their tumors were small - and possibly microscopic.

Ramirez and his colleagues found that the rate of disease-free survival at 4.5 years was 96.5 percent with open surgery and 86 percent with minimally-invasive surgery. Even after adjusting for issues such as age, weight, the stage of the tumor and whether it had spread to the lymph nodes, minimally-invasive surgery was not as good for survival.

In the retrospective database study, four-year death rates were 5.3 percent with conventional “open” surgery and 9.1 percent with minimally-invasive surgery.

SOURCES: bit.ly/2zgwOfV and bit.ly/2zgVXap The New England Journal of Medicine, online October 31, 2018.