Using nomograms to predict prognostic factors in young colorectal mucinous and signet-ring cell adenocarcinoma patients

Due to insufficient quantitative evaluation of the clinic-pathological features and prognosis of young colorectal cancer (CRC) with mucinous adenocarcinoma (MAC) and signet-ring cell carcinoma (SRC), the aim of our study was to develop a nomogram to identify the prognostic predictors for overall survival (OS) in this patient population. We retrospectively evaluated the patient records of MAC and SRC patients aged ≤ 40 years. Kaplan–Meier analysis and log-rank testing were performed to estimate OS. A nomogram predicting OS was created for risk quantitation and decision tree analysis was performed for patient grouping. With a median follow-up of 36.5 months, we included a total of 90 young CRC patients for analysis. The overall cumulate 5-year OS rate was 57.7% (95% confidence interval (CI): 45.1–68.5%). The estimated 5-year OS was 62.9% (95% CI: 48.5–74.3%) for MAC and 37.3% (95% CI: 14.4–61.2%) for SRC (P=0.021). The recurrence rate was significantly greater in the SRC group compared with the mucinous group (52.4 compared with 26.1%, P=0.047). In the multivariate Cox regression model, preoperative carcinoembryonic antigen (CEA) levels and cycles of adjuvant chemotherapy (CT) were found to be an independent prognostic factor for OS (hazard ratio (HR): 2.43; 95% CI: 1.13–5.62, P=0.024; HR: 0.21; 95% CI: 0.083–0.57, P=0.002, respectively). Nomograms predicting 3- and 5-year OS were established that performed well (concordance index (c-indexes) of 0.636, 95% CI: 0.549–723) for OS. For MAC and SRC disease, a greater proportion of young patients present with advanced disease, and the prognosis for young SRC patients is poorer than MAC. Furthermore, preoperative CEA levels and cycles of adjuvant CT seem to independently affect the OS in this patient population.