Are more aggressive treatments associated with better prognosis among patients with young-onset rectal cancer?

Purpose: The incidence of rectal cancer in young adults is gradually increasing. Patients with young-onset rectal cancer tend to receive more aggressive treatment than older patients. However, the results of studies on the prognosis of patients with young-onset rectal cancer are controversial. This study aimed to retrospectively investigate the prognosis and treatment of patients with young-onset rectal cancer, compared with the older group. Methods: : Patients diagnosed with rectal cancer who underwent curative surgical resection between 2015 and 2019 were enrolled. Propensity-matched sex and clinical stage were used to compare prognoses between young-onset and older groups. Results: : A total of 604 patients were enrolled. Among them, 73 were aged 50 years or less, and 531 were over 50 years of age. After matching, 73 young-onset patients and 146 older patients (>50 years) were identified. More aggressive treatments were administered in the young-onset group than those in the older group, including neoadjuvant therapy (32.9% vs. 17.8%; P =0.012) and adjuvant therapy (74.0% vs. 42.5%; P <0.001). However, there were no significant differences in overall survival and progression-free survival. In subgroup analysis, young-onset female patients showed surprisingly worse outcomes than those in older female patients ( P =0.008). Moreover, females in the young-onset group had worse outcomes than males ( P =0.033). Conclusions: : With more aggressive treatment, patients with young-onset rectal cancer do not seem to have a better oncologic outcome than older patients. More precise and individualized treatment may be needed for patients with young-onset rectal cancer.