MELBOURNE – Residents of the mountain region of the United States are significantly less likely to receive postoperative treatment for advanced endometrial cancer, compared with residents of the Northeast or Midwest, according to an oral presentation made at the biennial meeting of the International Gynecologic Cancer Society.
Retrospective analysis of data from 228,511 patients registered in the National Cancer Data Base – 15.5% of whom were stage III or IV – showed that women living in the mountain region and the Midwest were also significantly more likely to be diagnosed with advanced stage disease than those living in the South (hazard ratio 1.29 and 1.27 respectively, P < .0001)
Dr. Sean Dowdy
Researchers also found having Medicaid insurance significantly increased the likelihood of being diagnosed with stage III-IV endometrial cancer (HR 1.51, P < .0001) and decreased overall survival, compared with individuals with private insurance or in managed care (HR 0.85).
“The aim of this study was to estimate the contribution of race and ethnicity, socioeconomic factors such as education and income, as well as place of residence on eventual cancer outcome,” said Dr. Sean Dowdy, professor and chair of gynecologic surgery at the Mayo Clinic.
“Specifically we looked at three questions: one was the factors that are associated with advanced stage at diagnosis, stage III-IV; whether patients received postsurgical treatment when they had advanced disease; and also their overall survival,” Dr. Dowdy told the conference.
While the study initially found that African American women were significantly more likely to be diagnosed with advanced disease than white women, this difference was no longer statistically significant after adjusting for other factors, such as the fourfold higher incidence of serous cancer in African American women.
African American women also had a reduced overall survival, compared with white women, although the study did not find any significant impact of race on treatment rates or the likelihood of being treated at a high-volume facility.
“I expected African Americans to have worse access, and to be diagnosed with advanced-stage disease, and I thought that that would be the reason for their reduced survival, but we actually didn’t see that,” Dr. Dowdy said in an interview.
“The other possibility is, there is something unique about African Americans, about their tumors or about their host response, so maybe their immunological response or something like that may impact their survival.”
The study also observed reduced survival among patients treated at low-volume facilities – although this represented a relatively small number of patients – and noted a twofold increase in reduced survival among patients aged over 80 years.
“In the age category, it’s not surprising that patients were less likely to be treated, but it’s surprising the magnitude of this, so patients that were 90 years were ten times less likely to be treated than patients who were in their 50s,” Dr. Dowdy told the audience.
Commenting on the negative impact of Medicaid and Medicare insurance, Dr. Dowdy pointed out that the study predated the introduction of the Affordable Care Act, and it was too early to tell what impact that might have on the outcomes for those patients without private insurance.
However he also called for more research into the racial disparities in overall survival.
“If the problem is access, then we need to put money into education, and we need to maybe change the system so that it’s more accessible,” Dr. Dowdy said.
“If it’s a biology thing then we need to figure out what that is and figure out whether there are specific treatments that we should be using in these patients.”
The study was supported by the Mayo Clinic, and there were no conflicts of interest declared.