Higher LNM rate and poorer prognosis of early-onset compared to late-onset T1 stage colorectal cancer: a large-population based study

As for T1 stage CRC, there is little knowledge of differences in lymph node metastasis (LNM) and prognosis between early-onset and late-onset CRC. To know that, we included 13,084 patients from the SEER database and 476 patients in T1 stage from our hospital to analyze difference of LNM and prognosis. Univariate and multivariate logistic analyses revealed that early-onset CRC was more likely than late-onset CRC to be positive for LNM. In addition, we found that T1b stage, poor differentiation and lymphatic invasion were risk factors for LNM. Specifically, we found that black race was a risk factor. Before propensity-score matching (PSM), we also found that early-onset CRC patients had better survival, as demonstrated by SEER data. After adjusting for confounding factors by PSM, we found that early onset remained a risk factor for LNM. Moreover, we found that patients diagnosed with early-onset CRC had a poorer prognosis than those diagnosed with late-onset CRC, which was demonstrated by analysis of SEER data and our own data. In conclusion, our study was the first to find that early-onset T1 stage CRC more frequently developed LNM, suggesting that endoscopic submucosal resection should be performed more carefully in these patients. Moreover, early-onset patients in the T1 stage also had poorer survival, suggesting that clinical doctors should pay more attention to early-onset patients.