Risk of Relapse and Efficacy of Adjuvant Chemotherapy in Localized Appendiceal Adenocarcinoma.
Relapse after resection of localized appendiceal adenocarcinoma is uncommon, and adjuvant chemotherapy was not associated with improved recurrence-free survival.
Risk of Relapse and Efficacy of Adjuvant Chemotherapy in Localized Appendiceal Adenocarcinoma.
IMPORTANCE: Relapse risk and benefit of adjuvant chemotherapy after resection of appendiceal adenocarcinoma (adenocarcinoma) are uncertain.
To identify clinicopathologic and genomic factors associated with relapse and assess efficacy of adjuvant chemotherapy in localized adenocarcinoma.
Included a complete localized cohort of 439 patients with stage I to III adenocarcinoma from UT MD Anderson, of whom 202 underwent surgery at UT MD Anderson and also included a validation cohort of 128 patients with stage II adenocarcinoma from Memorial Sloan Kettering Cancer Center.
after adjustment, adjuvant chemotherapy showed no recurrence-free survival benefit; the hazard ratio sits near no effect
There were 439 patients with localized adenocarcinoma (median age, 56.5 [IQR, 22.2-83.7] years; 50% female and 50% male) managed at MD Anderson between January 2000 and February 2024.
Of 202 MDA surgical patients, 19 (9.4%) had a relapse including 9 (6%) patients with stage II and 8 (19.5%) of patients stage III disease.
Five-year OS was 95.7% without vs 77.2% with relapse (hazard ratio [HR], 5.50; 95% CI, 3.07-9.83; P < .001).
TP53 mutation in goblet cell tumors (HR, 6.93; 95% CI, 1.50-31.00; P = .01) and GNAS mutation in nongoblet tumors (HR, 17.0; 95% CI, 3.09-93.3; P = .001) were associated with greater risk of relapse.
These results demonstrate that relapse after resection of localized adenocarcinoma is uncommon. Molecular profiling and histopathologic subtype refine risk. Adjuvant chemotherapy were not associated with benefit.