Introduction:

Tumor recurrence and progression are common among non-muscle invasive bladder cancer (NMIBC) patients. Timely surveillance is a critical component of high-quality care that allows for prompt identification and treatment of tumor recurrence and progression. However, studies report low and varied compliance with surveillance recommendations. Thus, we sought to determine the frequency of timely NMIBC surveillance in a large community-based cohort and to identify risk factors for low surveillance levels.

Methods:

Adult NMIBC patients diagnosed from 1/1/2001-6/30/2015 within Kaiser Permanente Southern California (KPSC) were identified using data from the KPSC cancer registry, and patients who were health plan members at the time of diagnosis were eligible for the study. Patients were excluded if they had a diagnosis of cancer within the prior 5 years, other than non-melanoma skin cancer; radical cystectomy/urinary diversion (RC/UD) surgery, infusion chemotherapy, or hospice care within 3 months of diagnosis; or health plan membership loss or death within 12 months of diagnosis. Surveillance procedures were identified via codes for cystoscopy or tumor resections 61-365 days post-diagnosis. Tumor resection codes were included to minimize missing a surveillance episode (e.g., in case fulguration, rather than cystoscopy, was coded). Unique surveillance episodes/procedures had to be separated by >75 days to be counted. Outcome variables were >2 surveillance procedures (all patients) and >3 procedures for patients with high-risk tumors (T1, high grade, or carcinoma in situ tumors), which represent the minimum expected surveillance based on guidelines and clinician input. Patient and provider characteristics were extracted from the electronic health record and administrative databases. Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using generalized linear mixed models with a binary outcome and urologist as a random effect to account for clustering of patients within providers.

Results:

Among 5,037 NMIBC patients, 13% had <2 surveillance procedures. Compared to patients 60-69, younger (<50, OR=0.58, 95% CI: 0.39-0.85) and older (>=80, OR=0.66, 95% CI: 0.51-0.85) patients were significantly less likely to receive at least 2 surveillance procedures in the first year after diagnosis. Hispanic patients were less likely than non-Hispanic white patients to receive at least 2 surveillance procedures (OR=0.76, 95% CI: 0.59-0.97). Patients with higher comorbidity levels (Charlson Comorbidity Index [CCI] score >=2) were less likely to have at least 2 surveillance procedures in the year after diagnosis than patients with a CCI score of 0 (OR=0.64, 95% CI: 0.52-0.79; the CCI calculation ignored bladder cancer). The proportion of patients with >=2 surveillance procedures increased over time (per-year OR=1.07, 95% CI: 1.05-1.10). 

Patients with high-risk tumors were more likely to receive at least 2 surveillance procedures (OR=1.38, 95% CI: 1.16-1.65). However, 40% of the 2,635 patients with high-risk tumors received <3 surveillance procedures. Among these high-risk patients, patients with greater comorbidity levels (CCI >=2 vs. 0) were less likely to receive at least 3 surveillance procedures (OR=0.72, 95%: 0.59-0.89). Null associations with >=3 surveillance procedures were observed for age, sex, race/ethnicity, neighborhood household income, oncology specialist, urologist years at KPSC, and urologist’s bladder cancer experience based on number of RC/UD surgeries in the prior year. Surveillance of >=3 procedures in the year following diagnosis improved over the study years (per-year OR=1.04, 95% CI: 1.02-1.07) and was greater for patients with urothelial tumors (OR=1.97, 95% CI: 1.21-3.20).

Conclusion:

Surveillance levels among higher-risk patients were lower than expected, with few identifiable predictors of low surveillance levels. Further exploration is needed, and next steps will include targeted chart reviews to determine potential causes. Additionally, while most patients received at least 2 surveillance procedures in the year following diagnosis, there are still some patients who did not receive this minimum expected surveillance. Thus, even for this level of surveillance, care could be improved further within a large, integrated delivery system. Additional research is needed to assess compliance with surveillance recommendations in other types of healthcare systems.

Funding: National Cancer Institute of the National Institutes of Health