Use of presurgical (neoadjuvant) chemotherapy on the rise for advanced ovarian cancer, but may not be beneficial for some patients

Dana-Farber Cancer Institute

• September 06, 2016

The use of presurgical chemotherapy for patients with metastatic ovarian cancer has risen dramatically following research that showed potential benefits to the approach, investigators at Dana-Farber and other institutions report in a new study. In one set of patients, however, the approach generally resulted in shorter survival times than the traditional surgery-first method.
The researchers found that patients with stage IIIC ovarian cancer – in which the tumor is larger than 2 cm and the cancer has spread to the upper abdomen – tended to live significantly longer if they underwent surgery before chemotherapy treatment rather than receiving chemotherapy first. By contrast, patients with stage IV ovarian cancer – in which cancer growth has spread throughout the body – fared similarly whether they received surgery or chemotherapy first.
The findings suggest that in carefully selected patients with stage IIIC ovarian cancer, initial treatment with tumor-removal surgery may offer a survival advantage over presurgical, or “neoadjuvant,” chemotherapy. For patients with stage IV disease, however, neoadjuvant chemotherapy is at least as effective as initial surgery and decreases the chances of admission to an intensive care unit or re-hospitalization.
“We were surprised to find that women with stage IIIC disease who received neoadjuvant chemotherapy seemed to fare worse than those who had surgery first,” said study senior author Alexi Wright, MD, MPH, of Dana-Farber's Susan F. Smith Center for Women’s Cancers. “We expected the survival times for the two groups would be roughly equal since that is what prior studies had shown.” The first and corresponding author of the paper is Larissa A. Meyer, MD, MPH, of University of Texas MD Anderson Cancer Center.
By analyzing data on 1,538 women with advanced ovarian cancer, the investigators found that those with stage IV disease survived for a similar period whether they received neoadjuvant chemotherapy or primary cancer surgery. For patients with stage IIIC disease, however, the median survival was 33 months in the neoadjuvant chemotherapy group compared to 43 months in the primary surgery group.
Patients with stage IIIC disease who received neoadjuvant chemotherapy were more likely to have less than 1 cm of tumor left after surgery, but that extensive reduction in tumor volume didn’t confer a survival benefit, the investigators found. By contrast, patients who had similarly minute amounts of cancer after primary surgery survived longer than patients who received neoadjuvant chemotherapy. This suggests that the cancer cells remaining after neoadjuvant chemotherapy may be resistant to further chemotherapy.
The study sought to gauge the impact of a 2010 European clinical trial that found patients with advanced ovarian cancer who received neoadjuvant chemotherapy survived at least as long, and had fewer treatment-related complications, as those who initially underwent surgery to remove the tumor. (Neoadjuvant chemotherapy helps reduce the size of tumors, potentially making surgery easier. Whether or not neoadjuvant chemotherapy is used, surgery is typically followed by a course of chemotherapy to eliminate any remaining cancer cells.)
In their analysis of patient data, the investigators found that the use of neoadjuvant therapy for women with advanced ovarian cancer rose significantly between 2003 and 2012: from 16 percent to 34 percent for women with stage IIIC disease, and from 41 percent to 62 percent for women with stage IV disease.
“For years we thought that all women with ovarian cancer should have surgery before chemotherapy until two large European clinical trials found that giving chemotherapy first might be safer,” Wright said. “Many American physicians doubted the study results – and even spoke out against them publicly – but our study shows that physicians are using neoadjuvant chemotherapy a lot more frequently than we expected.”
The authors suggest that future studies should examine the effectiveness of neoadjuvant therapy in patients with different amounts of cancer remaining after surgery.