Long-term Outcomes of Endoscopic and Surgical Resection for High-risk pT1 Colorectal Cancer in Elderly Patients

Surgical resection (SR) is recommended for pT1 colorectal cancer (CRC) with high-risk histological features for lymph node metastasis. However, endoscopic resection (ER) alone without additional SR is sometimes chosen for elderly patients due to surgical tolerance. Comparative studies on outcomes and prognosis between ER and SR remain limited.

This retrospective study evaluated the outcomes of ER alone or SR in elderly patients (≥80 years) with high-risk pT1 CRC between 2008 and 2021.

A total of 59 patients were included, with 23 in the ER group and 36 in the SR group (additional SR after ER: 21, initial SR: 15). In the ER/SR groups, median age was 83 years, and the male ratio was 52%/64%, respectively. Median of Prognostic Nutritional Index (PNI) was 46.9/51.0. Median lesion size was 20 mm in both groups. Pathological findings showed pT1b in 96%/92%, lymphovascular invasion in 35%/33%, and budding grade ≥2 in 22%/28%. Treatment-related complications occurred in 7%/8% in each procedure, with one surgery-related death. Over a median follow-up of 57/63 months, no recurrences or disease-specific deaths were observed. The 5-year survival rates were 90%/81%, with no significant difference in overall survival (P = 0.12). PNI <43.4 was identified as a prognostic risk factor, and in the ER group, patients with low PNI showed significantly worse survival.

There was no significant difference between the outcomes of ER alone and SR among elderly patients with high-risk pT1 CRC. PNI can be a valuable predictor of prognosis in the ER group.