Not All Ovarian Cancer Patients Getting Staging Biopsies
A team of UC Davis Cancer Center and California Cancer Registry researchers have found that more than a quarter of women thought to have early-stage ovarian cancer do not receive the recommended lymph node biopsies needed for proper staging of the disease. This failure of lymph node biopsy staging nearly doubles the risk of death from ovarian cancer.
Rosemary Cress, an epidemiologist and research program director at the California Cancer Registry and colleagues identified patients diagnosed with apparent early-stage epithelial ovarian cancer (EOC) between 1998 and 2000 from cancer registries in New York and California. Detailed surgical staging information was collected from medical records for each of the 721 patients.
The study results were published online a few weeks ago in the journal Gynecology Oncology and will be published in the journal’s April print edition.
The researchers found nearly 90% of patients had removal of the omentum and evaluation of bowel serosa and mesentery but only 72% had assessment of retroperitoneal lymph nodes and the majority of patients did not receive biopsies of other peritoneal locations.
Proper staging of the ovarian cancer should include the following: peritoneal cytology, multiple peritoneal biopsies, omentectomy, and pelvic and para-aortic lymph node sampling.
The study found that the five-year survival for women with early-stage disease who had the node biopsies was 84%, compared with 69% of those who did not have the tests.
Gynecologic oncologists were nearly six-and-a-half times more likely to perform lymph node biopsies than other surgical specialists, and nearly four times more likely to perform all recommended staging biopsies.
“Early-stage patients had nearly twice the risk of death if they didn’t have the lymph nodes tested,” said Rosemary Cress, an epidemiologist and research program director at the California Cancer Registry, associate adjunct professor in the Department of Public Health Sciences at UC Davis and the study’s lead author. “Hopefully, this should raise the awareness among physicians that it’s really important to do lymph node biopsies in these patients.”
Why some surgeons don’t remove lymph nodes during ovary surgery for early-stage cancer patients is a matter of speculation, said Gary Leiserowitz, chief of Gynecologic Oncology at the UC Davis Cancer Center, who was the senior author of the study. But the tests are important, he said, because patients with positive lymph nodes are given a more advanced stage diagnosis and prescribed follow-up chemotherapy treatment.
Cress and Leiserowitz also found that follow-up chemotherapy did not improve survival for women whose ovarian cancers were properly staged with appropriate lymph node biopsies, and can avoid unnecessary additional treatment. Thus, only when patients did not have the lymph nodes tested did chemotherapy improve survival, a finding the researchers attribute to the role chemotherapy likely plays in killing cancer cells that have spread beyond the ovaries.
Leiserowitz said he hopes the results of the study will help educate the medical community and patients about the value of appropriate cancer treatment.
“If you are going to treat someone with a cancer, you really have an obligation to understand what the published practice guidelines are, and adhere to them as well as you can, or refer the patient to someone else who will,” he said.
UC Davis press release, Feb 2, 2011
Surgical staging of early stage epithelial ovarian cancer: Results from the CDC-NPCR ovarian patterns of care study; Cress RD, Bauer K, O’Malley CD, Kahn AR Schymura MJ, Wike JM, Stewart SL, Leiserowitz GS; Gynocologic Oncology, available online January 21, 2011; doi:10.1016/j.ygyno.2010.12.359