Characteristics Associated With Nonreceipt of Surveillance Testing and the Relationship With Survival in Stage II and III Colon Cancer.

We investigated characteristics of patients with colon cancer that predicted nonreceipt of posttreatment surveillance testing and the subsequent associations between surveillance status and survival outcomes. This was a retrospective cohort study of the Surveillance, Epidemiology, and End Results database combined with Medicare claims. Patients diagnosed between 2002 and 2009 with disease stages II and III and who were between 66 and 84 years of age were eligible. A minimum of 3 years' follow-up was required, and patients were categorized as having received any surveillance testing (any testing) versus none (no testing). Poisson regression was used to obtain risk ratios with 95% confidence intervals for the relative likelihood of No Testing. Cox models were used to obtain subdistribution hazard ratios with 95% confidence intervals for 5- and 10-year cancer-specific and noncancer deaths. There were 16,009 colon cancer cases analyzed. Patient characteristics that predicted No Testing included older age, Black race, stage III disease, and chemotherapy. Patients in the No Testing group had an increased rate of 10-year cancer death that was greater for patients with stage III disease (subdistribution hazard ratio = 1.79, 95% confidence interval: 1.48, 2.17) than those with stage II disease (subdistribution hazard ratio = 1.41, 95% confidence interval: 1.19, 1.66). Greater efforts are needed to ensure all patients receive the highest quality medical care after diagnosis of colon cancer.

Surveillance Colonoscopy in Older Stage I Colon Cancer Patients and the Association With Colon Cancer-Specific Mortality.

OBJECTIVES: Guideline-issuing groups differ regarding the recommendation that patients with stage I colon cancer receive surveillance colonoscopy after cancer-directed surgery. This observational comparative effectiveness study was conducted to evaluate the association between surveillance colonoscopy and colon cancer-specific mortality in early stage patients. METHODS: This was a retrospective cohort study of the Surveillance, Epidemiology, and End Results database combined with Medicare claims. Surveillance colonoscopy was assessed as a time-varying exposure up to 5 years after cancer-directed surgery with the following groups: no colonoscopy, one colonoscopy, and ≥ 2 colonoscopies. Inverse probability of treatment weighting was used to balance covariates. The time-dependent Cox regression model was used to obtain inverse probability of treatment weighting-adjusted hazard ratios (HRs), with 95% confidence intervals (CIs) for 5- and 10-year colon cancer, other cancer, and noncancer causes of death. RESULTS: There were 8,783 colon cancer cases available for analysis. Overall, compared with patients who received one colonoscopy, the no colonoscopy group experienced an increased rate of 10-year colon cancer-specific mortality (HR = 1.63; 95% CI 1.31-2.04) and noncancer death (HR = 1.36; 95% CI 1.25-1.49). Receipt of ≥ 2 colonoscopies was associated with a decreased rate of 10-year colon cancer-specific death (HR = 0.60; 95% CI 0.45-0.79), other cancer death (HR = 0.68; 95% CI 0.53-0.88), and noncancer death (HR = 0.69; 95% CI 0.62-0.76). Five-year cause-specific HRs were similar to 10-year estimates. DISCUSSION: These results support efforts to ensure that stage I patients undergo surveillance colonoscopy after cancer-directed surgery to facilitate early detection of new and recurrent neoplastic lesions.

The association between post-treatment surveillance testing and survival in stage II and III colon cancer patients: An observational comparative effectiveness study.

BACKGROUND: The best strategy for surveillance testing in stage II and III colon cancer patients following curative treatment is unknown. Previous randomized controlled trials have suffered from design limitations and yielded conflicting evidence. This observational comparative effectiveness research study was conducted to provide new evidence on the relationship between post-treatment surveillance testing and survival by overcoming the limitations of previous clinical trials. METHODS: This was a retrospective cohort study of the Surveillance, Epidemiology, and End Results database combined with Medicare claims (SEER-Medicare). Stage II and III colon cancer patients diagnosed from 2002 to 2009 and between 66 to 84 years of age were eligible. Adherence to surveillance testing guidelines-including carcinoembryonic antigen, computed tomography, and colonoscopy-was assessed for each year of follow-up and overall for up to three years post-treatment. Patients were categorized as More Adherent and Less Adherent according to testing guidelines. Patients who received no surveillance testing were excluded. The primary outcome was 5-year cancer-specific survival; 5-year overall survival was the secondary outcome. Inverse probability of treatment weighting (IPTW) using generalized boosted models was employed to balance covariates between the two surveillance groups. IPTW-adjusted survival curves comparing the two groups were performed by the Kaplan-Meier method. Weighted Cox regression was used to obtain hazard ratios (HRs) with 95% confidence intervals (CIs) for the relative risk of death for the Less Adherent group versus the More Adherent group. RESULTS: There were 17,860 stage II and III colon cancer cases available for analysis. Compared to More Adherent patients, Less Adherent patients experienced slightly better 5-year cancer-specific survival (HR = 0.83, 95% CI 0.76-0.90) and worse 5-year noncancer-specific survival (HR = 1.61, 95% CI 1.43-1.82) for years 2 to 5 of follow-up. There was no difference between the groups in overall survival (HR = 1.04, 95% CI 0.98-1.10). CONCLUSIONS: More surveillance testing did not improve 5-year cancer-specific survival compared to less testing and there was no difference between the groups in overall survival. The results of this study support a risk-stratified, shared decision-making surveillance strategy to optimize clinical and patient-centered outcomes for colon cancer patients in the survivorship phase of care.

Post-treatment surveillance testing of patients with colorectal cancer and the association with survival: protocol for a retrospective cohort study of the Surveillance, Epidemiology, and End Results (SEER)-Medicare database.

INTRODUCTION: Although the colorectal cancer (CRC) mortality rate has significantly improved over the past several decades, many patients will have a recurrence following curative treatment. Despite this high risk of recurrence, adherence to CRC surveillance testing guidelines is poor which increases cancer-related morbidity and potentially, mortality. Several randomised controlled trials (RCTs) with varying surveillance strategies have yielded conflicting evidence regarding the survival benefit associated with surveillance testing. However, due to differences in study protocols and limitations of sample size and length of follow-up, the RCT may not be the best study design to evaluate this relationship. An observational comparative effectiveness research study can overcome the sample size/follow-up limitations of RCT designs while assessing real-world variability in receipt of surveillance testing to provide much needed evidence on this important clinical issue. The gap in knowledge that this study will address concerns whether adherence to National Comprehensive Cancer Network CRC surveillance guidelines improves survival. METHODS AND ANALYSIS: Patients with colon and rectal cancer aged 66-84 years, who have been diagnosed between 2002 and 2008 and have been included in the Surveillance, Epidemiology, and End Results-Medicare database, are eligible for this retrospective cohort study. To minimise bias, patients had to survive at least 12 months following the completion of treatment. Adherence to surveillance testing up to 5 years post-treatment will be assessed in each year of follow-up and overall. Binomial regression will be used to assess the association between patients' characteristics and adherence. Survival analysis will be conducted to assess the association between adherence and 5-year survival. ETHICS AND DISSEMINATION: This study was approved by the National Cancer Institute and the Institutional Review Board of the University of Central Florida. The results of this study will be disseminated by publishing in the peer-reviewed scientific literature, presentation at national/international scientific conferences and posting through social media.