QS135 - Health Economics and Outcomes in Advanced Colon Cancer: The Cost of Chemotherapy First

Purpose/Background: Background: Colon cancer treatment pathways have variable costs and outcomes. The total cost of treatment course and clinically important outcomes, such as ostomy formation, are important considerations when determining the best treatment course for patients with advanced colon cancer.

Objective: The aims of this study are to 1) determine the total cost of advanced colon cancer treatment pathways that include surgical intervention and 2) evaluate secondary outcomes of stoma formation rate and emergency room utilization.

Methods/Interventions:

Design: This is a cross-sectional observational study using the limited data set version of the Medicare Standard Analytic Files (SAFs), which contain claims for inpatient hospital (100% sample), outpatient hospital (100% sample) and doctor office visits (5% sample). To capture the full spectrum of cancer treatment pathways, this study utilized the 5% sample population from June 2016 to December 2020. The episode of care for this study is defined as the time from index treatment (chemotherapy, surgery, immunotherapy or radiation) and 365-day post-index follow-up. Subgroup analysis of patients who underwent chemotherapy first vs. surgery first was performed.
Setting: Hospital systems accepting Medicare in the United States.
Patients: Medicare beneficiaries eligible for Medicare Part A and enrolled in Medicare Part B with diagnosis of advanced colon cancer who underwent treatment between 2017 and 2019 were included in the sample. Patients were excluded if they had appendiceal, rectal or anal cancer, cancer treatment (e.g., chemotherapy) within 6 months prior to the treatment in index years, or did not have complete 1 year follow-up data.
Main outcome measures: The primary outcome measure was estimated total cost of colon cancer treatment pathway.

Results/Outcomes:

Results: In this cohort of 3,647 patients, 2,677 underwent chemotherapy only while 970 underwent chemotherapy plus surgery. A generalized linear regression was used to determine adjusted total estimated cost, adjusting for age, gender, race, region, and Elixhauser comorbidity. Patients who underwent chemotherapy only had an adjusted cost of $10,003.6 (95%CI: 9,151.7-10.933.6) compared to $31,917.2 (95% CI: 28,672.7-35,528.8) (p < 0.001) when both chemortherapy and surgery were performed. One-hundred fifty-three patients (5.7%) in the chemotherapy only group had an ostomy during their treatment compared to 152 patients (15.7%) in the chemotherapy plus surgery group (p < 0.001).
On subgroup analysis 121 patients underwent chemotherapy first followed by surgery and 849 underwent surgery first followed by chemotherapy. The adjusted cost for the chemotherapy first group was $39,799.1 (95%CI: 35,077.0-45,157.0) versus $33,688.1 (95%CI: 31,073.2-36,523.1) (p < 0.01). The rate of ostomy formation was 24.0% in the chemotherapy first group compared to 14.5% in the surgery first group (p < 0.001) and the rate of ER visits within 30 days of surgery was 9.9% in the chemotherapy first group versus 9.7% (p=N.S.).

Conclusion/Discussion:

Conclusions: The data reveal higher costs with combined chemotherapy and surgery as compared to chemotherapy alone in the treatment of advanced colon cancer. However, in those patients treated with both chemotherapy and surgery, a chemotherapy first approach was associated with the highest proportion of stoma and higher costs. In the treatment of advanced colon cancer, a surgery first approach may lead to substantial cost savings and fewer overall stomas without additional emergency room visits.