"This study provides further evidence that surgery to remove as much tumor as possible at the initial operation is the best option for most patients," says William Cliby, M.D., Mayo Clinic gynecologic oncologist and lead investigator of the study. "It helps to define a topic that is often debated within our specialty -- the benefit of radical surgery for advanced ovarian cancer patients." Dr. Cliby says that data demonstrate many surgeons choose the more cautious route of less surgical intervention, and this results in shorter overall survival.
Dr. Cliby and his team of researchers found that aggressive surgery greatly improves survival rates for patients with the most severe disease spread. They also found similar five-year survival rates in most cases for patients undergoing radical and non-radical surgery, indicating to the researchers that aggressive surgery is not a significant risk factor, but instead aids in survival. In those patients with the highest volume of disease (carcinomatosis), the researchers found that radical surgery greatly improved the five-year survival rates (44 percent versus 17 percent).
Having a general preference towards maximum surgical intervention, Dr. Cliby and his fellow Mayo Clinic surgeons see the results of a survey conducted by the Society of Gynecologic Oncologists in 2001 as troubling, with 45.5 percent of respondents citing lack of evidence for improved survival as a primary rationale against performing aggressive surgical resection in specific cases of advanced ovarian cancer. The American Cancer Society predicts over 16,000 women in the United States will die from ovarian cancer this year, and Dr. Cliby's team hope their study will promote a trend toward more aggressive surgeries when warranted. "Our study showed a significant survival advantage when a more aggressive surgical approach is used," says Dr. Cliby. "Hopefully we'll see increased education and a movement towards a more uniform surgical management of ovarian cancer."
Dr. Cliby's team notes that while surgery is just one part of the treatment for advanced ovarian cancer, it is the one variable gynecologic oncologists treating this disease can most control. To improve the outcomes of this disease, they hope to see more research in resistance to chemotherapy, prevention of recurrent disease, and earlier detection.
This study's purpose was to estimate the effect of aggressive surgery on overall survival rates for ovarian cancer patients. The main outcome measures were residual disease after tumor reduction surgery, frequency of radical surgical procedures and five-year, disease-specific survival. Radical surgery procedures included diaphragmatic surgery, bowel resection, splenectomy or extensive abdominal peritoneal stripping or resection.
Because several other factors are part of the decision to perform surgery, especially more radical surgeries, Dr. Cliby's team also looked at risks related to age, preoperative medical condition and operative time. They found that residual disease and radical surgery were the only factors that consistently predicted survival.
The study cohort of 194 women was assembled from patients who underwent primary surgery for stage IIIC ovarian cancer at Mayo Clinic between 1994 and 1998.
Other Mayo researchers assisting in the study include: Giovanni Aletti, M.D.; Sean Dowdy, M.D.; Bobbie Gostout, M.D.; Monica Jones, M.D.; Robert Stanhope, M.D.; Timothy Wilson, M.D.; and Karl Podratz, M.D., Ph.D.
For more information on treatment of ovarian cancer at Mayo Clinic, go to www.mayoclinic.org/ovarian-cancer.