Pediatric adenocarcinoma in Korea: A multicenter study

Purpose Adenocarcinoma is an extremely rare malignancy in the pediatric population. Research regarding pediatric adenocarcinoma is very rare in Korea. This study aimed to investigate the clinical features of pediatric adenocarcinomas of various primary organ sites in Korea. Materials and Methods Pediatric patients under 18 years, diagnosed with adenocarcinoma of various sites between January 1995 and December 2016, were included. We retrospectively reviewed patient and tumor characteristics and calculated survival estimates, reported as 5-year survival rate and 95% confidence interval. Results Of 80 patients (median age, 15 years; range, 10 to 17 years), 37 (46.3%) were men, and 24 (30%) had a family history of cancer or underlying disease relevant to malignancy. The cancer locations were the colon and rectum (n=32), ovaries (n=18), stomach (n=15), lung (n=4), small bowel (n=1), and other sites (n=10). Totally, 54.8% patients (42/77) had stage 3 or 4 disease. The median follow-up period was 2.0 years (range, 0 to 20.4). The 5-year overall survival estimate for all patients, and for those with stomach, colorectal, ovarian, and other cancer sites were 57.9%±11.5%, 58.2%±25.7%, 41.5%±18.2%, 87.5%±16.2%, and 64.0%±34.4%, respectively. The 5-year survival rate differed significantly between categories of adenocarcinomas into gastrointestinal (GI) (44.7%) and non-GI adenocarcinomas (78.8%) (p=0.007). The 5-year survival rate also differed significantly according to carcinoembryonic antigen level (69.3% in < 3 ng/mL, 23.8% in > 3 ng/mL; p < 0.001). Conclusion In pediatric patients, adenocarcinomas arise from various organs and are often diagnosed at advanced stages. Large, prospective studies for their accurate clinical characteristics and prognostic factors are needed.