It is not unusual nowadays to find patients at the center of conception and development of research or clinical management of their diseases, not only as informed protagonists, but also as consultants/advisors who can best describe or define first-hand the needs and shortcomings that may arise throughout their experience. They can be trusted to raise awareness about key points that need to be developed. Because of this, the work to understand early-onset colorectal cancer (EOCRC) should not only include clinicians and researchers, but also patients (and consequently patient advocacy organizations) as integral partners for the development of knowledge about a disease. EOCRC is a clear example of the importance of this inclusion given this community's specific psychosocial needs and the stigmas associated with this diagnosis. This publication is a joint effort of the aforementioned partners, to reach an integrative needs assessment, and is hopefully only a first step towards making this collaboration a standard practice rather than an exception to the rule.

Colorectal Cancer (CRC) in patients with ages younger than 50 years, also known as EOCRC or Early age of Onset, is a global health issue, with a disease burden undeniably on the rise. The establishment of CRC screening strategies could reflect a comparative decrease in late-onset disease incidence. Conversely, cases of CRC appearing at a younger age have increased significantly -and not only due to the lack of screening in these ages-to raise attention in multiple fields (epidemiology, research, clinical practice) in recent years [1]. Data regarding this increase in incidence is widely documented within the US population [2]. The incidence of CRC increased by 1.27% (95% CI, 0.95%–1.60%) annually from 2001 to 2012 and by 3.00% (95% CI, 2.06%–3.95%) annually from 2012 to 2017 [3]. This is even more remarkable when divided into colon and rectal cancer subsets, showing that an adult born in the 90s has twice the risk of colon cancer and four times the risk of rectal cancer than an adult born in the 50s [2]. This shows that the alarming trends in increase are more striking for rectal cancer. Beyond and based on this data, research on the increase in the incidence of EOCRC has been extended to other parts of the world. This trend is confirmeding, although with certain nuances [[3], [4], [5]]. The reasons for the lack of data are found, in the absence of national registries or in the fact that the studies carried out are minor (single institutions). These factors are more pronounced in developing countries. Despite this, it has been possible to demonstrate an increase in incidence equivalent to that of the US in some countries such as Australia, Canada, India, Germany, the UK or Denmark. However, there are some without such marked increase (e.g., Germany, Denmark, Poland). As example of variability, during 2008–2012, age-standardized CRC incidence rates in adults <50 ranged from 3.5 per 100 000 (95% CI 3.2 to 3.9) in India (Chennai) to 12.9 (95% CI 12.6 to 13.3) in Korea [5]. Even so, it is non-existent in a few countries, and there is even some with decrease (Italy, Austria and Lithuania) [[3], [4], [5]]. The steepest increases in young adults were in Korea (average annual per cent change (AAPC), 4.2 (95% CI 3.4 to 5.0)) and New Zealand (AAPC, 4.0 (95% CI 2.1 to 6.0)) [5].

Together with the geographical disparities regarding increasing incidence trends, there are also some remarkable findings emerging that seem more evident in the EOCRC subset compared to late-onset CRC, such as disparities concerning inherent factors (sex or race/ethnicity). Some examples are: a worse prognosis in relation to the male sex [5,6], or the American black race [[6], [7], [8]], or also important variations of these regarding geographic areas [8,9,9,10,10,11].

Finally, an important aspect that serves to focus and define the object of this work is that EOCRC was initially associated with the hereditary component of CRC in general, and that is why many of the studies focused specifically on the identification of Lynch syndrome in this age range [11,12]. Nowadays, it is known that a well-defined and stable proportion would correspond to different conditions of susceptibility to cancer, particularly CRC, and therefore 5 out of every 6 EOCRC cases are sporadic/Microsatellite stable [12,13,13,14]. Thus, this subset may essentially contribute to the global increase in incidence.

In summary, the undeniable and global importance that EOCRC is acquiring, makes a joint and worldwide effort necessary to try to unravel its causes and underlying pathogenic features. We are currently considering a critical evaluation of the main aspects already identified, including prevailing gaps, along with possible paths to follow. There will be special attention on the sporadic nature and variability that it seems to present as capital characteristics.