Recent clinical trials have proven that treatment for relapsed ovarian cancer is not a standard “one size fits all.” After a relapse, areas where tumors spread and grow in the body vary in every individual.
Seven out of ten patients with ovarian cancer may see their cancer return. It has been an accepted practice to have a second surgery prior to chemotherapy. However, according to an article in the National Cancer Institute, whether a patient should undergo secondary surgery for relapsed ovarian cancer is questionable when comparing the results of three recent clinical trials.
Two large-scale clinical trials GOG-0213 and DESKTOP III have recently been conducted to determine whether or not secondary surgery will prolong life. Unfortunately, their conclusions were dissimilar.
A third trial SOC-1 recently completed in China will be reporting final results shortly. Interim results of the SOC-1 trial found that patients who agreed to secondary surgery did live longer without cancer progression than the patients who did not receive secondary cytoreduction surgery (SCS).
The eligibility requirements in the three trials are not similar which makes comparison somewhat difficult. As one example, the patient population participating in the clinical trials was different. These factors can have a major impact on trial results. Also, the site of the relapse varies. Cancer can return as a “spot” on an organ, or it can be scattered across many different organs in which case it would require a complicated operation.
Comparison of Secondary Surgery In Three Clinical Trials:
- GOG-0213 final report: Overall survival of 50.6 months with surgery and 64.7 months without surgery
- DESKTOP III final report: Overall survival of 53.7 months with surgery and 46.2 months without surgery
- SOC-1 interim report: Overall survival was 58.1 months with surgery group and 53.9 months without-surgery
The disparities in the three trials raise questions about the efficacy of secondary surgery. Yet the DESKTOP III trial proved that patients meeting the trial’s strict criteria can have longer overall survival than patients who only receive chemotherapy. It should be noted that the enrollment criteria in DESKTOP were created towards enrolling patients who would most likely find a second operation beneficial after relapse.
Interim reports from the SOC-1 trial showed favorable results for patients undergoing secondary surgery. No deaths were reported within sixty days after treatment in either group. Investigators noted a thirty-seven percent crossover by patients in the no surgery group to the surgery group when they experienced a relapse.
About DESKTOP III
Four hundred seven individuals with relapsed ovarian cancer were enrolled in the DESKTOP III trial. The majority of these patients had received chemotherapy when they were diagnosed initially. The trial criteria required a remission period of no less than six months after chemotherapy. Three criteria, which included having had all visible evidence of disease removed, the minimum buildup of fluid in the abdomen, and being able to perform normal unrestricted daily activities, were designed to encourage chances of successful secondary surgery. Note that a build up of fluid in the abdomen is a sign that the cancer may have spread.
Patients were assigned randomly for treatment with surgery and chemotherapy or only chemotherapy.
Surgeons removed visible disease in seventy-five percent of participants. Survival in these patients was twice the number of patients who only had a portion of cancer removed. (62 months vs. 28 months).
Factors Contributing to The Difference in Trial Results
Trial researchers in the DESKTOP III and SOC-1 trials used the standard criteria to select participants. However, the criteria in the GOG-0213 trial differed in that enrollment was based on a surgeon’s determination on whether the cancer could be removed completely with surgery.
There are differences in the studies that make it difficult for a strong comparison, but results from DESKTOP and SOC-1 trials prove surgery is valuable.
Not All Hospitals Are Created Equal
Several doctors referenced the fact that very few patients with ovarian cancer are treated at medical centers or hospitals that conduct a good volume of surgery for relapsed ovarian cancer. Many are not treated by a gynecologic oncologist. Therefore, the doctors caution that they would not see the same results they found in the clinical trials.
Additionally, although survival for white patients has improved, the same does not apply to Black patients or those living in rural areas.