Neither neoadjuvant nor adjuvant chemotherapy are routinely administered to patients with muscle-invasive bladder cancer despite the potential for both treatments to improve survival, according to findings of a population-based study.
“Patients having surgery for bladder cancer should have chemotherapy, either before or after surgery,” lead researcher Christopher Booth, MD, FRCPC, of Queen’s University Cancer Research Institute in Canada, said in a press release. “Efforts are needed to improve uptake of this treatment, which appears to be vastly underutilized.”
Booth and colleagues used the population-based Ontario Cancer Registry to identify 2,944 patients who underwent cystectomy for bladder cancer between 1994 and 2008. They compared the utilization of adjuvant and neoadjuvant chemotherapy among these patients during three time periods: 1994-1998, 1999-2003 and 2004-2008.
The rate of patients who received neoadjuvant chemotherapy remained stable (mean, 4%) during the entire study period. Utilization of adjuvant chemotherapy increased from 16% in 1994-1998 to 18% in 1999-2003, then to 22% in 2004-2008 (P=.001).
Adjuvant chemotherapy was utilized more frequently among patients with T3 or T4 advanced-stage tumors (OR=1.83; 95% CI, 1.38-2.46), those with node-positive disease (OR=8.10; 95% CI, 6.2-10.7) and patients with lymphovascular invasion (OR=1.53; 95% CI, 1.11-2.15). Researchers determined younger patients were more likely to receive either neoadjuvant or adjuvant chemotherapy, as were patients who underwent surgery at a hospital associated with a regional cancer center (neoadjuvant chemotherapy, OR=1.73; 95% CI, 1.18-2.55; adjuvant chemotherapy, OR=1.43; 95% CI, 1.12-1.83).
Among all patients, the rate of 5-year OS was 29% (95% CI, 28%-31%) and the rate of 5-year cancer-specific survival was 33% (95% CI, 31%-35%).
Among patients who received adjuvant chemotherapy, 5-year OS was 29% (95% CI, 25-33) and cancer-specific survival was 28% (95% CI, 24-33). After adjustments for disease and patient characteristics, researchers determined patients who underwent adjuvant chemotherapy demonstrated improved OS (HR=0.71; 95% CI, 0.62-0.81) and cancer-specific survival (HR=0.73; 95% CI, 0.64-0.84) compared with those who did not.
“Results from our study demonstrate that chemotherapy given after surgery improves patient survival — probably on the same order of magnitude as chemotherapy before surgery,” Booth said.
Among patients who underwent neoadjuvant chemotherapy, 5-year OS was 25% (95% CI, 17-34) and cancer-specific survival was 28% (95% CI, 18-39). The 5-year OS rate was considerably lower than the 49% to 57% rate reported in prior trials, but selection and referral biases, the association between greater cystectomy case volumes and better outcomes, and differences in surgical techniques may have contributed to the difference, according to the researchers.
“Given the potential for perioperative chemotherapy to improve patient outcomes, further efforts are needed to understand reasons for underutilization,” Booth and colleagues wrote. “The comparatively poor outcomes of patients in routine practice compared with survival reported in clinical trials suggest a substantial efficacy-effectiveness gap that requires further attention to improve the outcomes of patients with muscle-invasive bladder cancer in the general population.”
Disclosure: The researchers report no relevant financial disclosures.