A large study found that women with bladder cancer generally have lower overall survival rates than their male counterparts.
Though men are three to four times more likely to be diagnosed with bladder cancer, a recent study has found that women with late-stage disease are dying at a higher rate.
Tracy Lynn Rose from the University of North Carolina led a study that identified 23,981 patients with stage 4 bladder cancer from the National Cancer Data Base and compared survival rates between men and women.
“Bladder cancer is actually relatively unique in that it is much more common in men, but once a person has the cancer, women are actually more likely to die from it,” Rose said in an interview with CURE. “And if you look [at] many other cancers, women typically have better survival rates.”
Women had a lower median overall survival (OS) rate compared with men (8.0 months versus 9.8 months), even after adjusting for factors such as the percentage of those getting systemic chemotherapy, which women who had advanced disease were less likely to receive (45 percent versus 52 percent).
However, even after adjusting for care received, women still faced a poorer prognosis than their male counterparts — especially those with late-stage disease.
“Although this difference may partially account for the survival disadvantage noted among women compared with men, OS remains lower in women independent of chemotherapy use,” the study says, implying that there may be other factors at play.
The study also adjusted for age; year of diagnosis; race; insurance status; distance to and location of facility; income; education; facility type; comorbidities; presence of lymph node and distant metastases; and receipt of chemotherapy.
Tumor types, Rose said, may play a role in survival disparities. “Women have higher rates of basal tumor subtypes, which are more aggressive,” she said.
The study also found that factors typically correlated with longer OS included younger age (women, on average, were diagnosed older than men) and white race (a higher percentage of women diagnosed with pancreatic cancer were black).
When comorbidities were examined, findings showed that women did not have a higher rating on the Charlson-Deyo comorbidity index.
But not all groups of women with bladder cancer had increased death rates. Researchers found that “[w]omen with metastatic [bladder cancer] treated on clinical trials do not have a survival disadvantage,” the study’s authors wrote. Rose said that this is because unlike in the real world treatment setting, clinical trials are much more fair and regulated.
“I think that it’s a very controlled patient population, so we know that all the women and the men on clinical trials receive the exact same treatment in the exact same way,” she said. “Maybe something about the way they’re treated in the real world may be affecting their survival.”
One of these barriers, Rose described, is the notion that women are more frail than men, especially since the average age of diagnosis is 73, according to the American Cancer Society. A frail patient may be less likely to be offered treatment like chemotherapy, which can cause debilitating side effects.
“It’s important [for women] to work with their providers to see whether or not they’re candidates for chemotherapy and if that would work for them,” Rose said.
As immunotherapy makes its way into the treatment of bladder cancer, Rose is hoping more women will live longer.
“Because immunotherapy is [typically] more tolerable [… women] may be more likely to receive these treatments and result in higher OS rates, but that is yet to be seen,” Rose said.