Clinicopathological differences between familial colorectal cancer type X and sporadic cancer in an isolated area of spain

Aim Very few studies have compared the epidemiological characteristics of patients with familial colorectal cancer Type X ( FCCTX ) with those of sporadic colorectal cancer (S‐ CRC ). The aim of this study was to compare clinicopathological characteristics and survival between FCCTX and S‐ CRC in patients from a historically isolated geographical region. Method A retrospective study was carried out of patients with S‐ CRC and FCCTX treated in the Canary Islands. Family and personal history of colorectal cancer ( CRC ) were recorded, together with genetic (microsatellite instability), immunohistochemical and clinical variables. Results Forty‐eight (10.6%) of 451 patients were classified as FCCTX and the remaining 403 (89.4%) as S‐ CRC . Age at the diagnosis of tumour was significantly lower in FCCTX than in S‐ CRC (64.06 ± 12.65 years vs 69.13 ± 10.80 years; P  =   0.01; Z  = −2.48). Patients with FCCTX had a larger number of synchronous tumours ( P  = 0.09). Recurrence was significantly higher in FCCTX than in S‐ CRC (18.7% vs 8.6%; P  = 0.01). Survival correlated significantly with the number of first‐degree and second‐degree relatives with CRC ( P  = 0.04; OR: 1.368, 95% CI : 1.01–1.84, and P  = 0.04; OR: 1.363, 95% CI : 1.08–1.65) and with the total number of cases of CRC in the immediate family ( P  < 0.01; OR : 1.377, 95% CI : 1.17–1.61). Recurrence‐free time was significantly lower in patients with FCCTX (log‐rank = 0.01). Conclusion Significant differences were found in several demographic and clinicopathological variables between patients with FCCTX and patients with S‐ CRC . These included increased tumour presentation under the age of 50 years and a higher recurrence rate in patients with FCCTX , suggesting an increased risk of CRC in this group.