Dissertation
Receipt of guideline-recommended post-treatment surveillance among stage II/III rectal cancer patients: utilization, factors associated with surveillance and the impact of surveillance on survival outcomes
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Autumn 2021
DOI: 10.17077/etd.006265
Abstract
Despite advances in rectal cancer management, patients with stage II/III disease have high recurrence rates and poor survival outcomes. Post-treatment surveillance, which typically incorporates a colonoscopy, carcinogenic embryonic (CEA) test, imaging tests and physician visits, has been proposed as a mechanism to detect asymptomatic recurrences early and improve survival outcomes. This dissertation aimed to add knowledge on post-treatment surveillance utilization for patients with stage II/III rectal cancer, and the factors associated with receipt of post-treatment surveillance for rectal cancer including the role of the surgeon in receipt of guideline-recommended post-treatment surveillance. Another aim of this study was to determine the association between receipt of stage II/III rectal cancer post-treatment surveillance and survival outcomes. This project sought to improve the measurement of post-treatment surveillance by taking into account that most rectal cancer patients received adjuvant therapy in the post-treatment surveillance timeline and controlling for potential confounders such as comorbidity and function-related indicators. Given the high recurrence rates and sub-optimal survival outcomes, the objective of this study was to describe post-treatment surveillance utilization, ascertain factors associated with post-treatment surveillance patterns of care and determine if post-treatment surveillance adherence is associated with better survival outcomes among stage II/III rectal cancer patients. We conducted a retrospective analysis of Surveillance, Epidemiology, and End Results-Medicare patients diagnosed between 2007 and 2013. Individual and composite measures of colonoscopy, CEA test, clinical history and physical exam, and imaging were used to measure receipt of post-treatment surveillance. Bivariate analyses were used to compare baseline demographic characteristics by receipt of post-treatment surveillance. Logistic regression was performed to determine factors associated with post-treatment surveillance adherence. Cox regression models were used to determine the association between receipt of guideline-recommended post-treatment surveillance and survival outcomes.
Receipt of guideline-recommended surveillance colonoscopy (55%), physician visits (54%), CEA tests (47%) and CTs (20%) was low at 14 months post-treatment. Approximately 33% either received all components of guideline-recommended post-treatment surveillance or had a recurrence detected (this was considered adherent since the goal of surveillance is to capture recurrence). Factors associated with receipt of post-treatment surveillance included younger age at diagnosis, being married, female gender and receipt of chemoradiotherapy. Patients who received surgery from high-volume surgeons were more likely to receive all four guideline-recommended post-treatment surveillance measures compared to those who received surgery from lower volume surgeons (OR=1.94; 95% CI: 1.08-3.50). In multivariate Cox regression models, receipt of post-treatment surveillance was not significantly associated with reduced risk of all-cause death (HR=0.73; 95% CI: 0.45-1.17) and cancer-specific mortality (HR=0.96; 95% CI: 0.49-1.88).
Overall, the results of the study add to the body of knowledge showing that most stage II/III rectal cancer patients do not receive guideline-recommended post-treatment surveillance. While previous research has shown that surgeon volume is significantly associated with receipt of peri-operative guideline-recommended care, the results of this study extend our knowledge on the role of surgeon volume in the receipt of guideline-recommended post-treatment surveillance. In addition, the results of this study support the findings from recent studies on this topic, which reported that receipt of guideline-recommended post-treatment surveillance was not associated with reduced risk of mortality among those who were alive and had no indication of recurrence at 15 months posttreatment; but this does not rule out likely survival benefits for those who had recurrences detected within one year of treatment completion. Our findings related to patterns of post-treatment surveillance in patients over 65 can be used to develop interventions that can help improve receipt of post-treatment surveillance and help meet the needs of stage II/III rectal cancer survivors. For example, interventions to improve the uptake of post-treatment surveillance should focus on the influence of patient and system level factors on adherence. Future randomized clinical trials could help more definitively determine optimal post-treatment intensity and surveillance strategies that maximize benefit and reduce the burden of unnecessary surveillance procedures.
Details
- Title: Subtitle
- Receipt of guideline-recommended post-treatment surveillance among stage II/III rectal cancer patients: utilization, factors associated with surveillance and the impact of surveillance on survival outcomes
- Creators
- Catherine Chioreso
- Contributors
- Mary Charlton (Advisor)Mary Schroeder (Committee Member)Irena Gribovskaja-Rupp (Committee Member)Knute Carter (Committee Member)Elizabeth Chrischilles (Committee Member)Charles Lynch (Committee Member)Eric Ammann (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Epidemiology
- Date degree season
- Autumn 2021
- Publisher
- University of Iowa
- DOI
- 10.17077/etd.006265
- Number of pages
- xvi, 76 pages
- Copyright
- Copyright 2021 Catherine Chioreso
- Language
- English
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 69-76)
- Public Abstract (ETD)
Stage II/III rectal cancers are prone to recurrence. Post-treatment surveillance can potentially catch recurrent cancer early enough to allow for receipt of curative treatment, thus improving survival outcomes. We carried out a study to describe stage II/III rectal cancer post-treatment surveillance utilization, determine factors associated with post-treatment surveillance adherence and ascertain whether receipt of post-treatment surveillance is associated with better survival outcomes. The study population for the retrospective cohort study includes SEER-Medicare stage II/III rectal cancer beneficiaries diagnosed between 2007 and 2013 who received curative surgery within 6 months of diagnosis. The results of this study suggest that, while receipt of post-treatment surveillance is low, it is more common among patients who received surgery from high-volume surgeons. Patient and clinical characteristics, such as age and comorbidity, are associated with receipt of post-treatment surveillance. Receipt of post-treatment surveillance was not significantly associated with lower risk of death. Future studies need to further determine the type of patients that can benefit from post-treatment surveillance.
- Academic Unit
- Epidemiology
- Record Identifier
- 9984210640402771
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