Abstract
Comparative studies of colorectal cancer (CRC) according to the age of onset have found differences between early-onset CRC (EOCRC) and late-onset CRC (LOCRC). Using this as a starting point, we wished to determine whether intermediate-onset CRC (IOCRC) might also be considered as an independent group within CRC. We performed a retrospective comparative study of the clinicopathological and familial features, as well as of the symptoms and their duration, of a total of 272 subjects diagnosed with CRC classified into three groups according to the age-of-onset (98 EOCRC, 83 IOCRC and 91 LOCRC). The results show that from a clinicopathological point of view, IOCRC shared certain features with EOCRC (gender, prognosis), and with LOCRC (multiple primary CRCs), whereas it also had characteristics that were specific for IOCRC (mean number of associated polyps). A gradual progression was observed from EOCRC to LOCRC from a greater family aggregation to sporadic cases, in parallel with a change of Lynch Syndrome cases to the sporadic microsatellite instability pathway, with the IOCRC being a boundary group that is more related to EOCRC. With respect to symptoms, duration and correlation with stages, IOCRC appeared more similar to EOCRC. Clinically, IOCRC behaves as a transitional group between EOCRC and LOCRC, with features in common with both groups, but also with IOCRC-specific features. Excluding cases with familial cancer history, the awareness for EOCRC diagnosis should be extended to IOCRC.
Highlights
Colorectal cancer (CRC) represents the third most common malignancy in developed countries [1,2]
It has been observed that microsatellite instability (MSI) does not explain the majority of early-onset CRC (EOCRC) cases, and some authors have suggested that EOCRC should not be considered to be intimately associated with hereditary forms of CRC [8,9,10,11]
Taking this as a starting point, the aim of the present study was to investigate whether intermediate-onset CRC (IOCRC) (51–69 years old at the time of diagnosis) might be considered as a different group within CRC according to the clinicopathological features of these tumors or if, on the contrary, it should be interpreted as a transitional group between EOCRC and late-onset CRC (LOCRC) in which the clinicopathological features progressively vary from those typical in EOCRC to those typical in LOCRC
Summary
Colorectal cancer (CRC) represents the third most common malignancy in developed countries [1,2]. Its pathogenesis is tightly related to the loss of genomic stability involving one of at least three major molecular pathways: chromosomal instability (CIN), microsatellite instability (MSI), and CpG island methylator phenotype (CIMP). Since the risk of developing CRC increases as individuals get older, early-onset CRC (EOCRC) represents a rare entity commonly related to hereditary forms of the disease (2–8% of all CRCs) [8]. From a clinical point of view, sporadic earlyonset tumors are more aggressive and confer poorer survival than the late-onset ones. They are more frequently associated with invasive phenotypes, early metastasis, and familial clustering [8,9,12]. It has been proposed that the molecular basis of CRC might be different for different ages of onset [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
