Removing metastatic disease from the diaphragm significantly increases survival rates in ovarian cancer patients

In a retrospective study looking back at a decade of surgeries, Mayo Clinic Cancer Center researchers have determined that surgery to remove metastatic disease from the diaphragm, in conjunction with other procedures to remove the primary diseased tissue in ovarian cancer patients, significantly increases survival rates. Study results were published in Gynecologic Oncology online.

"Surgeons have long believed that removing as much diseased tissue as possible is important for survival of cancer patients," said William Cliby, M.D., associate professor of obstetrics and gynecology at Mayo Clinic. "The choice of many surgeons to not resect diaphragm disease in ovarian cancer patients seemed counterintuitive, but it was based on the feeling that it might not improve survival. We sought to address this issue."

Dr. Cliby's team cited lack of evidence of survival benefit, concerns over safety (related to complexity and length of the surgery) and lack of surgeon experience as justifications often given for not proceeding with diaphragmatic surgery in advanced ovarian cancer patients. This study provided strong evidence of survival benefit. The five-year survival rates for patients with diaphragm disease who had optimal residual disease (less than 1 cm) was 55 percent for those undergoing diaphragm surgery versus 28 percent for those who did not.

The study group included 244 consecutive patients with primary ovarian cancer who were operated on at Mayo Clinic from 1994 through 1998 and from Aug. 1, 2002, through Aug. 31, 2004. Dr. Cliby and his colleagues found that at Mayo Clinic, the rate of diaphragm procedures for affected patients increased from 22.5 percent in the first period compared to 40 percent in the more recent period. They attribute this to increased surgeon experience, increased recognition of the importance of maximal effort for tumor resection and the cooperative working relationships with other surgical specialties at Mayo Clinic that provide the opportunity to train interdepartmentally and improve surgical techniques. "We hope to continue improving upon our ability to remove cancer disease from all affected areas," said Dr. Cliby. "With each operation, our surgeons become better equipped to handle the most difficult of surgeries, providing hope for more patients."

The researchers conclude that while health issues in some patients will complicate the success of surgery in general, and prevent the option of radical surgery, surgeons should work to increase the rate of tumor reduction, including diaphragm surgery, in appropriate cases.

In addition to Dr. Cliby, the research team included Giovanni Aletti, M.D.; Sean Dowdy, M.D.; and Karl Podratz, M.D., Ph.D.