Abstract 509P
Background
CRC incidence rates and human development index are demographically associated. It has been observed an increase of EOCRC incidence rates in the past years, predominantly reported by developed countries. However, such phenomenon is not well described globally, with unknown rates in low- and middle-income countries (LMIC), such as Brazil. We aim to evaluate the incidence rates and the clinicopathological features of EOCRC in a cancer center in Brazil.
Methods
We retrospectively collected clinicopathological data from patients diagnosed with CRC in a Brazilian cancer center from January 2016 to December 2019. Two groups were categorized based on the age-of-onset of CRC: EOCRC (< 50 years) vs. Late-onset CRC (LOCRC) (≥ 50 years). The groups were compared for gender, TNM stage at presentation, body mass index (BMI), sidedness, RAS, BRAF, and microsatellite instability status (MSI) using Fisher's exact test and Mann-Whitney U test, and statistical significance assumed at p<0.05. The mean age-of-onset of CRC patients was compared among the years (2016 to 2019) by one-way ANOVA test.
Results
A total of 388 patients were included, of which 76 (20%) were younger than 50 years. There was no statistically significant difference in the mean age-of-onset among the years 2016 to 2019 (p=0.789) (Table). The most common TNM stages were III (43% in EOCRC vs. 50% in LOCRC, p>0.05) and IV (36% vs. 27%, p>0.05). Left-sided tumors were represented by 74% vs. 64% (p=0.147). Likewise, there was no statistically significant difference between the groups in relation to gender, BMI, RAS, BRAF and MSI status. Table: 509P
| Groups | 2016 N (%) | 2017 N (%) | 2018 N (%) | 2019 N (%) |
| EOCRC | 13 (17.3) | 20 (18.5) | 25 (24.3) | 18 (17.6) |
| LOCRC | 62 (82.7) | 88 (81.5) | 78 (75.7) | 84 (82.4) |
| Median age | 60.9 | 60.9 | 59.2 | 61.7 |
Conclusions
In contrast to the data from developed countries, LMIC may present a distinct epidemiological trend of EOCRC, which strengths the hypothesis of the role of environmental factors as underlying causes of the rising incidence of EOCRC. Larger epidemiological study in Brazil is ongoing.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Oncoclínicas.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.