Competing Mortality Redefines the Net Benefit of Additional Surgery After Endoscopic Resection for T1 Colorectal Cancer in Older Adults

The oncologic benefit of additional surgery after endoscopic resection (ER) for the treatment of T1 colorectal cancer (CRC) remains uncertain in older adults, because competing causes of mortality may attenuate the gain in survival. The proportion of patients aged ≥ 80 years has increased steadily, reflecting population aging. For patients with high-risk T1 CRC, the aim of additional bowel resection is to remove occult lymph node metastasis and reduce the risk of recurrence, and long-term studies have shown improvements in T1 CRC-related outcomes. However, age modifies the magnitude of this benefit. Cohort studies of high-risk T1 CRC have shown only small differences in 5-year cancer-specific survival between patients who underwent additional surgery and those who did not. Moreover, most deaths in the nonsurgical group were attributable to causes other than cancer. Data from meta-analyses have further suggested that the survival advantage associated with surgery becomes evident only after 10 years, indicating a substantial delay in its benefits. In contrast, the incidences of perioperative morbidity and short-term mortality increase with age and have immediate effects on prognosis. These findings indicate that the net survival benefit of additional surgery in older patients depends on the balance between the delayed oncologic benefit and the immediate treatment-related risks. Thus, although surgery remains appropriate for selected fit individuals, clinicians should consider the pathologic risk, frailty, comorbidity burden, and competing mortality of individual older patients with pT1 CRC in their decision-making to optimize outcomes.