New ASCO Guidelines for Advanced Ovarian Cancer

The American Society of Clinical Oncology (ASCO) has released updated guidelines for neoadjuvant chemotherapy in newly diagnosed advanced ovarian cancer, introducing changes in patient selection and treatment strategies. The changes reflect emerging evidence on racial disparities, treatment outcomes, and quality of life considerations.

The publication of the new guidance follows dramatic shifts in treatment patterns over the past decade.

“There had been a big shift in how we were treating patients in the United States,” explained Stephanie Gaillard, MD, PhD, one of the authors of the updated guidelines. “We saw a substantial drop in the number of patients undergoing primary cytoreductive surgery for ovarian cancer from about 70% of patients in 2010 to only about 37% in 2021.”

The new guidelines maintain the recommendation for platinum/taxane-based neoadjuvant chemotherapy but introduce modifications regarding timing and duration.

“It’s still a recommendation that gynecologic oncologists are involved in determining whether someone is eligible for primary cytoreductive surgery or should undergo neoadjuvant chemotherapy first,” Gaillard noted. “We emphasize that patients who are eligible for primary cytoreductive surgery should undergo surgery as opposed to receiving neoadjuvant chemotherapy.”

Alexander Melamed, MD, MPH, a gynecologic oncologist at Massachusetts General Hospital, Boston, who was not involved in authoring the updated guidelines, noted that additional evidence-based guidance is needed to individualize treatment plans. He pointed to four completed trials comparing neoadjuvant chemotherapy with cytoreductive surgery, noting, “When these trials have been pooled together in meta-analyses, there was a higher risk of mortality associated with primary cytoreductive surgery and a higher risk of severe complications.”

The updated guidelines take this higher risk for mortality with primary cytoreductive surgery into consideration, and patients who are not eligible for primary surgery would receive neoadjuvant chemotherapy, Gaillard noted.

Changes in Patient Selection

The 2025 guidelines describe a more nuanced approach for selecting patients for neoadjuvant chemotherapy vs primary cytoreductive surgery. While the 2016 ASCO guidelines primarily focused on disease burden and surgical resectability when selecting patients for neoadjuvant chemotherapy, the new recommendations incorporate additional factors.

The guidelines discuss recent findings showing that Black patients experience a 38% lower likelihood of undergoing cytoreductive surgery than non-Black patients. In addition, compared with non-Hispanic White women, Asian and Black women more frequently receive neoadjuvant chemotherapy with interval debulking surgery rather than primary cytoreductive surgery. According to the authors, these differences persist even after accounting for clinical factors, suggesting that structural barriers to healthcare access may play a role.

The guidelines discuss how affordability, availability, and accessibility mediate racial disparities in ovarian cancer care. According to the authors, structural inequities in healthcare access influence treatment quality for minority patients. Non-White patients face greater challenges in accessing gynecologic oncology consultations and standard-of-care combination therapy, leading to poorer survival outcomes, the guidelines say.

According to Melamed, the guidelines serve as an important tool for promoting healthcare equity. “Having recommendations and standards is incredibly important for achieving equity because once there is consensus on a best practice, it doesn’t matter if you’re rich, poor, or a patient of a particular racial or ethnic group — if you have the disease, you ought to have access to that standard,” he said.

The 2016 ASCO guidelines focused primarily on disease burden and surgical resectability, whereas the 2024 National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines for ovarian cancer focus more on oncologic outcomes and surgical considerations. Based on the NCCN guidelines, treatment selection for ovarian cancer is primarily determined by the histologic subtype, stage of disease, and whether the patient is a candidate for primary surgery. The 2025 ASCO guidelines, on the other hand, emphasize the importance of quality-of-life outcomes during treatment selection. The authors of the updated ASCO guidelines acknowledged that treatment decisions should consider both the duration and quality of life, particularly for elderly patients or those with multiple comorbidities.

Treatment Timing and Duration

The guidelines maintain the recommendations for platinum/taxane-based neoadjuvant chemotherapy described in the previous ASCO guidelines but introduce modifications regarding treatment timing and duration. The optimal window for interval cytoreductive surgery now falls after three to four chemotherapy cycles, allowing more individualized approaches based on patient response and tolerance.

In addition, postsurgical chemotherapy protocols have become more flexible. Rather than mandating a fixed number of cycles, the guidelines encourage tailoring treatment duration to individual patient factors including response assessment, performance status, and quality-of-life considerations.

The updated guidelines also emphasize the importance of genetic and molecular testing at diagnosis, which Melamed identifies as “absolutely central to treatment and deciding who receives maintenance therapy.” This is also recommended by the NCCN guidelines.

However, he highlighted the following practical challenge in molecular testing after neoadjuvant chemotherapy. “Probably 20% of patients have an exceptional response to neoadjuvant therapy, such that there is insufficient tissue at the time of their cytoreduction to do somatic testing,” he said.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

A notable difference between the 2016 and 2025 guidelines is the inclusion of HIPEC in the updated guidelines.

Commenting to Medscape Medical News, Gaillard explained the nuanced approach to HIPEC: “The committee discussed HIPEC extensively. We recognize that it may not be available at many centers and requires specially trained staff and dedicated resources. The reason for including HIPEC in the guidelines is to highlight that there have been studies that show a potential overall survival benefit.”

Melamed considers the recommendation of HIPEC to be one of the strongest aspects of the updated guidelines. “There have been two large trials and one smaller one that have shown that for patients treated with neoadjuvant chemotherapy, the addition of HIPEC appears to improve overall survival,” he explained.

Implementation Strategies

The authors acknowledged that barriers to healthcare delivery present significant challenges to the implementation of the guidelines. Limited access to gynecologic oncologists in rural areas, insurance coverage gaps, and varying surgical expertise across institutions complicate the delivery of optimal care. The guidelines also emphasize the need for solutions to ensure equitable access to recommended treatments.

Melamed noted that the decentralized structure of the healthcare system in the United States complicates the uniform adoption of guidelines, particularly in resource-limited settings, adding that “geographic region and local resources and expertise influence both access to treatment and outcomes.”

Although both the updated ASCO guidelines and NCCN guidelines emphasize the importance of evaluation by a gynecologic oncologist for determining the most appropriate treatment strategy, the scarcity of gynecologic oncologists is one of the most significant barriers to accessing optimal care, according to Gaillard. She proposes telemedicine consultations and enhanced communication between medical oncologists and gynecologic oncologists to ensure equitable access.

Gaillard also commented on the challenges in implementing a multidisciplinary treatment approach, the importance of which is emphasized in the updated guidelines.

“There can be a limited availability of the multidisciplinary team to be involved in this decision-making,” she said. “Ideally, patient assessment by a gynecologic oncologist would happen in person, but recognizing that availability is limited, it doesn’t necessarily have to. Sometimes, it can just be a conversation between a medical oncologist and a gynecologic oncologist detailing a treatment plan together.”

Looking Ahead

Gaillard noted that ovarian cancer is a very active field of research and that the guidelines may need to be updated again in the near future to incorporate novel treatment approaches.

“Newer and more effective targeted therapies based on tumor profiling are being developed,” she said. “These will hopefully move earlier in the treatment course for patients. Maybe we will not use chemotherapy in the future because we will have more directed and targeted therapies.”

She also emphasized the importance of early diagnosis in shaping future treatment guidelines for ovarian cancer.

“Neoadjuvant chemotherapy is predominantly used in situations where patients have very advanced disease and may not benefit from primary cytoreductive surgery,” she noted. “If we develop better diagnostic tools that will allow us to diagnose patients earlier, then we may not need to use neoadjuvant chemotherapy.”

All funding for the administration of the guideline development project was provided by ASCO. Gaillard reported receiving consulting or advisory fees from Verastem, Merck, AstraZeneca, and Compugen; research funding from AstraZeneca, Tesaro, Compugen, Genentech/Roche, Clovis Oncology, Tempest Therapeutics, Blueprint Pharmaceutic, Immunogen, Volastra Therapeutics, and Beigene; and patents, royalties, or other intellectual property from United States Patent Nos 10,258,604 and 10,905,659, licensed by Duke University to Sermonix. Melamed reported receiving research funding from the National Cancer Institute and the National Institutes of Health.

Christos Evangelou, PhD, is a freelance medical writer and science communications consultant.