Only 72 percent of patients with presumed early-stage disease had lymph nodes from the pelvis and abdomen tested for signs of cancer spread, despite published, professional guidelines for proper staging of the disease, an analysis of the medical records and cancer registry data for more than 700 patients in California and New York found.
The study also found that the five-year survival for women with early-stage disease who had the node biopsies was 84 percent, compared with 69 percent 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.
The study results were published online last week in the journal Gynecology Oncology and will be published in the journal’s April print edition.
“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.”
For the study, Cress identified patients diagnosed with apparent early-stage epithelial ovarian cancer between 1998 and 2000 from cancer registries in New York and California, then collected detailed information from patient medical records on the types of surgical staging procedures performed on 721 of the 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.
“Depending on the knowledge and expertise of the surgeon doing the operation, they may not know they need to do all the biopsies,” he said. “The literature is pretty consistent in showing that the people who have specialized knowledge in this – gynecological oncologists – are much more likely to follow the guidelines.”
Another reason some surgeons may not perform the lymph node biopsies, he said, is that they don’t believe the patient would benefit, either because of advanced age or because they have other serious illnesses, or both.
“If we have a patient who is medically unsuitable because of their age or medical conditions and is not a candidate for chemotherapy, you wouldn’t do all the staging biopsies,” he said. “But for a woman, say in her 40s who is otherwise healthy, it turns out to be critical, because chemotherapy could be lifesaving.”
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.
The study was paid for with a grant from the U.S. Centers for Disease Control and Prevention.
UC Davis Cancer Center is the only National Cancer Institute- designated center serving the Central Valley and inland Northern California, a region of more than 6 million people. Its top specialists provide compassionate, comprehensive care for more than 9,000 adults and children every year, and offer patients access to more than 150 clinical trials at any given time. Its innovative research program includes more than 280 scientists at UC Davis and Lawrence Livermore National Laboratory. The unique partnership, the first between a major cancer center and national laboratory, has resulted in the discovery of new tools to diagnose and treat cancer. Through the Cancer Care Network, UC Davis is collaborating with a number of hospitals and clinical centers throughout the Central Valley and Northern California regions to offer the latest cancer-care services. For more information, visit cancer.ucdavis.edu.