April 10, 2024
In a pilot study, Amanika Kumar, M.D., a gynecologic oncologist at Mayo Clinic in Minnesota, and colleagues found that CT plus tumor molecular subtyping of patients with advanced-stage high-grade serous ovarian cancer (HGSOC) provides crucial presurgical information. These two tests furnish results indicating which patients have low likelihood of successful disease resection and require significantly complex surgery. Gynecologic Oncology published the pilot study's findings in 2022.
Dr. Kumar and colleagues intend the CT plus molecular subtyping for use in tandem with other clinical factors to improve resectability prediction. Knowing with greater certainty whether disease resection is likely to be successful increases informed decision-making for the surgeon and the patient.
Significance of study results
Inspiring this study is what Dr. Kumar calls "an obsession with residual disease" of her gynecologic oncology team treating patients with HGSOC. This obsession developed because any postsurgical residual disease beyond 1 cm signifies that the resection will not improve the patient's situation, says Dr. Kumar. Resection to no gross residual disease is really the goal.
"This is why high-quality surgery is imperative for advanced ovarian cancer," she says.
Having the same outlook before and after surgery would be a significant setback for a patient who has HGSOC and the surgeon, as this operation is complex and involves:
- Surgery lasting 6 to 8 hours.
- Substantial blood loss.
- Work in all four abdominal quadrants.
- Significant risk.
Dr. Kumar notes that although the risk of death is low in HGSOC resection, risk of major complications is 10% to 15%.
"These are huge surgeries with a lot of costs," says Dr. Kumar. "We proceed with them, however, because this surgery, if resulting in no gross residual disease, is life-prolonging for a serious cancer problem. There's a big survival difference depending on amount of postsurgical residual disease."
At Mayo Clinic, this desire to achieve no gross residual disease has led to expansion of surgical education and services offered.
If a patient undergoes chemotherapy alone without surgery for HGSOC, however, Dr. Kumar indicates outcomes are "pretty bad — years of survival different than with high-quality disease resection."
Yet Dr. Kumar says she has seen patients opt out of surgery if longevity is not a goal, and she respects this position.
A CT scan can accurately predict resectability in about 60% of people who undergo surgery, which is good but not great, she says. With the addition of molecular subtyping as performed in this pilot study, however, the gynecologic oncologist also can learn the following critical information about a patient's disease, which conveys potential resection success:
- Tumor type.
- Tumor gene expression.
- Categorization by The Cancer Genome Atlas.
"Using more and novel information really personalizes patient care, particularly surgery," says Dr. Kumar.
Dr. Kumar and research colleagues call for a confirmatory study of this combination of resectability decision-making factors. They also believe that AI tools hold resectability prediction potential to help more patients. Currently, she and her colleagues are not using the molecular profiling and CT combination clinically to determine resectability due to the need for a prospective study to further validate this approach. Until then, they will continue determining resectability through physical exam, medical history and symptom assessment, and review of imaging results.
HGSOC treatment
For anyone diagnosed with ovarian cancer, high-quality surgery is critical for optimal outcome, says Dr. Kumar. Typically, patients diagnosed with HGSOC require chemotherapy and surgery. Conventional wisdom in the field indicates that the order of these treatments does not matter. However, Dr. Kumar and colleagues propose that upfront surgery produces the best outcomes if meaningful surgery leaves the patient without gross residual tumor.
A significant HGSOC surgical challenge this study attempted to rectify is the potential for the surgeon to discover, once opening the patient in the OR, that meaningful disease resection is impossible. This potential makes novel resectability prediction methods desirable.
The nature of HGSOC
Many know ovarian cancer as a silent killer with virtually no detectable symptoms. Eventually, 70% of patients diagnosed with ovarian cancer develop advanced disease spreading throughout the abdomen and sometimes the thorax, indicating poor prognosis, says Dr. Kumar.
Despite this prognosis, however, she indicates that highly effective treatment that can achieve remission is now available to help these patients.
"We are known for our advanced ovarian cancer treatment at Mayo Clinic and are constantly trying to push the edge. We want patients to see us in critical situations where we can make an impact, and we believe we can offer improved oncologic and surgical outcomes."
Referral of patients with HGSOC
For surgeons uncertain about performing HGSOC surgery resulting in less than 1 cm of gross residual disease, Dr. Kumar invites Mayo Clinic referrals. She notes that Mayo Clinic gynecologic oncologists prioritize innovative, multidisciplinary and team-based care.
Dr. Kumar also mentions that there is now good evidence — such as a 2016 publication by Cowan and colleagues in Annals of Surgical Oncology — that patients who have surgery with a gynecologic oncologist at a high-volume center have better outcomes compared with those who do not receive this type of care.
Other factors she says are critical for successful HGSOC care include anesthesia support and involvement of capable radiologists. These factors characterize Mayo Clinic's care for people with this complex disease.
"We are known for our advanced ovarian cancer treatment at Mayo Clinic and are constantly trying to push the edge," she says. "We want patients to see us in critical situations where we can make an impact, and we believe we can offer improved oncologic and surgical outcomes. Most patients we operate on with HGSOC go back to work after surgical recovery, if not retired, and activities that give them joy — living a life that they value."
For more information
Kumar A, et al. Into the future: A pilot study combining imaging with molecular profiling to predict resectability in ovarian cancer. Gynecologic Oncology. 166;2022:508.
The Cancer Genome Atlas (TGCA). National Cancer Institute Center for Cancer Genomics.
Cowan RA, et al. Is it time to centralize ovarian cancer are in the United States? Annals of Surgical Oncology. 2016;23:989.
Refer a patient to Mayo Clinic.