Comparing the characteristics of colorectal cancer in young versus old patients

IntroductionThe overall lifetime risk of developing colorectal cancer (CRC) is approximately 4% in men and women. Over the past few decades, there has been an increase in incidence of CRC in the young population (defined as 50 years and under) despite an opposite trend in the older population (over 50 years old). Furthermore, more advanced disease has been observed at the point of diagnosis in young patients. Although recognised environmental and genetic factors play a role in this increase, the exact aetiology in this age group is unknown, but is likely multifactorial. Our study aimed to compare the differences in presentations, tumour characteristics and outcomes in patients with CRC according to age group.MethodsA prospectively maintained endoscopy database of all colorectal cancers at a London district general hospital between January 2019 and May 2021 was interrogated in conjunction with our colorectal multidisciplinary team meeting outcomes. Data were collected on age, presentation, indication for initial scope, tumour size and site, and biochemical parameters. We compared differences between the 55 year olds and under with the over 55 year olds. Categorical variables were analysed using the chi-squared test and the Fischer’s exact test. Continuous variable were analysed using two tailed T-test. Significant values were considered when p<0.05. All data was performed In R version 1.4.1106.ResultsThere were 160 patients included in this study. There were 86 females and 74 males. The median age was 72 years old (IQR: 31-94). There were 39 patients in the 55 years and under category and 121 in the over 55 category. There were significant differences in initial presentation with younger patients most commonly presenting with rectal bleeding (33.3%) and abdominal pain (10.2%) whereas older patients presented with iron deficiency anaemia (28.1%) and change in bowel habits (19%) (p = <0.01). Furthermore, there was significantly more lymphovascular invasion in younger patients when compared with older patients (53.8% vs 33% p<0.03). In the younger population the sigmoid colon was the most common site of malignancy (25.6%) compared to the rectum in the older population (24.0%). There was no difference in TNM stage at presentation between the two groups (p=0.93). Figure 1 shows the survival analysis between the two groups.ConclusionsYounger patients present differently than older patients with colorectal cancer. Older patients present much more commonly with iron deficiency anaemia compared with younger patients. Furthermore, younger patients present with greater lymphovascular invasion than older patients. Despite differences, survival appears to be similar between the two groups.