| Objectives:The purpose of this study was to explore the differences in clinicopathological features,treatment delay,pathological stages and prognosis between young-onset colorectal cancer patients and colorectal cancer patients aged 50 years and older.It will be helpful to manage young-onset colorectal cancer patients better and provide basis for clinical decision-making.Methods:In a retrospective cohort study,all pathologically diagnosed young-onset colorectal cancer patients(<50 years)were selected and a part of colorectal cancer patients aged 50 years and older according to the proportion of 1:4 were randomly selected in Zhongda Hospital affiliated to Southeast University from March 1,2014 to September 31,2021.The clinical characteristics,pathological features,pathological stages and treatment delay between young-onset colorectal cancer patients(n=121)and colorectal cancer patients aged 50 years and older(n=443)were compared.The patients were followed up by telephone and outpatient service from March 1,2014 to February 1,2019,and the 3-year overall survival rates of patients between different age groups were compared.Results:1.The most common symptoms in colorectal cancer patients were hematochezia and abdominal pain.Compared with patients aged 50 years and older,young-onset colorectal cancer patients were more likely to have abdominal pain(49.6% vs 39.5%,P=0.046).The tumor locations,gross types and pathological stages were similar between the two groups,but young-onset colorectal cancer had higher proportions of d MMR(20.0% vs 10.9%,P=0.012),mucinous adenocarcinoma(11.6% vs5.6%,P=0.023)and high-grade adenocarcinoma(17.3% vs 9.4%,P=0.021).2.The median treatment delay of young-onset colorectal cancer patients was slightly longer than patients aged 50 years and older(80 days [IQR 32-167] vs 53 days [IQR 20-159],P=0.028),and patient’s delay was the contributing factor for the significantly longer treatment delay in both age groups(P=0.000,P=0.000,respectively).In both age groups,the treatment delay of stage I-II colorectal cancer was longer than that of stage III-IV colorectal cancer,especially among youngonset colorectal cancer patients.3.In the multivariate analyses,age was not the factor leading to treatment delay among colorectal cancer patients,but residence,tumor location,presence or absence of acute intestinal obstruction during the course of disease were significantly correlated with treatment delay.The treatment delay of residents who didn’t live in Nanjing was 1.43 times(95%CI 1.13-1.81,P=0.003)longer than that of residents who lived in Nanjing.The treatment delay of patients with acute intestinal obstruction during the course of disease was 0.31 times(95%CI 0.19-0.48,P=0.000)shorter than that of patients without acute intestinal obstruction.Patients with rectal cancer were more likely to have delayed treatment,with 1.48 times(95%CI 1.17-1.87,P=0.001)longer than colon cancer patients.4.As of January 31,2022,77 of 84 young-onset colorectal cancer patients had been followed up with a follow-up rate of 91.7%;293 of 322 patients aged 50 years and older had been followed up with a follow-up rate of 91.0%.The 3-year overall survival rates of colorectal cancer patients were calculated by the method of Kaplan-Meier and the survival curves were drawn.The results showed that the 3-year overall survival rates of young-onset colorectal cancer patients and colorectal cancer patients aged 50 years and older were 86.0% and 74.6% respectively,and the difference was statistically significant(P=0.038).Stratified analysis based on pathological stage indicated that for stage I-II colorectal cancer,the 3-year overall survival rate was 100.0% in young-onset colorectal cancer patients and 91.5% in patients aged 50 years and older(P=0.067);for stage III-IV colorectal cancer,the 3-year overall survival rate was 72.9% in young-onset colorectal cancer patients and 56.6%in patients aged 50 years and older(P=0.071).Conclusions:1.Young-onset colorectal cancer patients and colorectal cancer patients aged 50 years and older had similar clinical symptoms,tumor locations,gross types and pathological stages,but young-onset colorectal cancer had higher rates of d MMR,mucinous adenocarcinoma as well as high-grade adenocarcinoma,and young-onset colorectal cancer patients had a higher incidence of abdominal pain.2.The median treatment delay of young-onset colorectal cancer patients was slightly longer than that of colorectal cancer patients aged 50 years and older,and patient’s delay was the main factor resulting in treatment delay,while treatment delay did not have a negative impact on pathological stages.3.In multivariate analyses,age was not a factor resulting in delayed treatment among colorectal cancer patients,but residents who didn’t live in Nanjing,patients without acute intestinal obstruction during the course of disease and patients with rectal cancer were significantly correlated with treatment delay.4.The overall prognosis of young-onset colorectal cancer patients was better than that of colorectal cancer patients aged 50 years and older.In the future,studies with a larger sample size are needed to explore the difference in prognosis between young-onset colorectal cancer patients and colorectal cancer patients aged 50 years and older for different pathological stages. |
