Assessing Risk Factors for Progression Among Patients With Advanced Ovarian Cancer After Response to First-line Platinum-Based Chemotherapy

To identify patients with high-risk, advanced ovarian cancer (OC) who may benefit from new treatments, researchers reviewed patient chart data to assess risk factors for cancer progression in these patients after administration of first-line, platinum-based chemotherapy (Future Oncol. 2021;4263-274. doi:10.2217/fon-2021-0018).

Ovarian cancer has the highest rate of mortality of all gynecologic cancers in the United States. Although most patients respond to first-line treatment, the disease progresses in roughly 70% of these patients within 3 years. 

The current standard of care for first-line treatment of patients with OC is 1) primary debulking surgery followed by platinum-based chemotherapy with a taxane with or without bevacizumab or 2) the same chemotherapy regimen given before interval debulking surgery and further therapy. Poly(ADP-ribose) polymerase inhibitors are approved by the Food and Drug Administration for maintenance therapy in OC; niraparib for all patients, olaparib for those with harmful BRCA mutations, and olaparib plus bevacizumab for those with tumors that are homologous recombination deficient. 

“Although there is guidance regarding prognostic factors for survival in patients with OC, there is no guidance regarding prognostic factors for progression,” wrote Shannon Westin, MD, MPH, Department of Gynecologic Oncology and Reproductive Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, and colleagues, adding, “Real-world databases allow for data capture from a much larger and more diverse patient population than clinical studies.”

To assess risk factors for cancer progression in these patients, the Dr Westin and team used the Flatiron Health database to identify US patients with stage III or IV OC who had first-line, platinum-based chemotherapy after primary or interval debulking surgery. The researchers collected data charted from January 2011 through October 2018, then used Cox proportional hazards modeling to assess associations between baseline factors and overall survival (OS) or time to next treatment (TTNT). “Here, it was necessary to use TTNT as a proxy for PFS [progression-free survival] because of inherent limitations in data capture within the Flatiron Health database,” noted Dr Westin and team.

Using these methods, they found that patients who had interval debulking surgery had shorter TTNTs and OSs than patients who had primary debulking surgery. Similarly, patients with stage IV disease had shorter TTNTs and OS than patients with stage III disease.

In addition, OS and TTNT were worse in patients with the wild-type BRCA gene, in those who received neoadjuvant chemotherapy, in patients with residual disease after debulking surgery, and in those with a higher International Federation of Gynecology and Obstetrics stage.

However, according to the researchers, these findings were limited by “the percentage of patients included in the study who had unknown tumor BRCA status (42% of all patients)….Despite the limitations, real-world data from [electronic health records] provide a useful supplement to clinical trial data by allowing for large retrospective analyses that are not possible within a clinical trial setting,” the authors wrote. 

“Real-world data confirmed prognostic factors for survival in OC that had been previously identified in clinical trials,” they concluded.