QS209 - Disparities in Surgical Management and Outcomes of Non-Metastatic Appendiceal Adenocarcinoma

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Purpose/Background: Appendiceal adenocarcinoma is often identified incidentally after appendectomy and may require further oncologic resection with right hemicolectomy for staging or treatment after diagnosis. This study aimed to characterize how racial and socioeconomic factors influence surgical management and outcomes in patients with non-metastatic appendiceal adenocarcinoma.

Methods/Interventions: Patients from the National Cancer Database from 2006-2020 with a diagnosis of appendiceal adenocarcinoma were identified and stratified by race, insurance status, and community type. Patients with Stage IV disease were excluded. Multiple logistic regression was performed to assess the independent effects of these strata on time to first surgery and definitive surgery, the surgical procedure performed, adequacy of lymph node harvest for staging ( < 12 vs. ≥12 lymph nodes), surgical approach, and 30- and 90-day mortality while controlling for age and sex. Regression coefficients (R) were calculated for continuous variables and odds ratios (OR) were calculated for binary variables.

Results/Outcomes: 2,552 patients were identified with a diagnosis of Stage 0-III appendiceal adenocarcinoma (9.8% Stage 0, 26.4% Stage 1, 52.0% Stage 2, 11.8% Stage 3). Patients were 51.4% male with mean age 61.5 ± 14.2 years. Table 1 displays the proportions of patients in each demographic group with a subset of regression results. Average time to first surgery and definitive surgery were 7.7 and 22.5 days respectively. There was no significant difference in time to first surgery or definitive surgery by race, however uninsured patients had a shorter time to first surgery (reference group privately insured; R = -5.4, p< 0.05) and definitive surgery (R = -5.4, p< 0.05). Patients in rural communities had a longer time to definitive surgery (reference group metropolitan; R = 11, p< 0.05) as did males (R=4.8, p< 0.05). The majority of patients underwent hemicolectomy (56.8%) or partial colectomy (26.4%). Being uninsured was more strongly associated with undergoing total colectomy than was being privately insured (OR 5.02, p< 0.005). Living in rural communities was more strongly associated with undergoing total proctocolectomy than was living in metropolitan communities (OR 19.3, p< 0.001). Overall 30- and 90-day mortality rates were 1.9% and 3.0% with no significant difference in mortality, adequacy of lymph node harvest, or surgical approach by race, insurance status, or community type. Patient age was associated with increased mortality at 30 and 90 days (R=1.07, p< 0.001 for both) as was being male (OR 2.84, p< 0.005 at 30 days, OR 2.35, p< 0.005 at 90 days).

Conclusion/Discussion: While socioeconomic differences were not associated with increased 30- and 90-day mortality for patients with non-metastatic appendiceal adenocarcinoma, disparities exist in time to definitive surgery for patients in rural communities, and these patients and uninsured patients are more likely to undergo more extensive colonic resections which may affect their quality of life. Some of these results are encouraging, however further studies are needed to better understand these identified disparities and how they affect long term patient outcomes.