ESD outcomes favor low-risk CRC care

Patients with low-risk T1 colorectal cancer had no recurrences or cancer-related deaths after endoscopic treatment alone, while additional surgery in higher-risk cases reduced local recurrence but did not improve distant outcomes or disease-specific survival, according to a large prospective study conducted in Japan.

In the multicenter cohort study published in Clinical Gastroenterology and Hepatology, investigators led by first author Takuro Hamada, MD, of the Department of Gastroenterology at Hiroshima University Hospital, Japan, evaluated long-term outcomes after endoscopic submucosal dissection (ESD).

Among 383 patients with T1 colorectal cancer followed for more than 5 years, none of the 102 patients classified as low-risk experienced recurrence or died from colorectal cancer. In contrast, all 10 recurrences (4%) and five cancer-related deaths (2%) occurred in the 281 patients with high-risk features.

Implications for practice

For physicians, the findings support ESD alone as definitive treatment in appropriately selected patients with low-risk disease. The absence of recurrence suggests that routine intensive surveillance strategies may be unnecessary in this group, potentially allowing for less frequent colonoscopy and imaging.

In patients with high-risk features, the data reinforce a more nuanced, individualized approach. While additional surgery reduced local recurrence, it did not meaningfully change distant recurrence or disease-specific survival, suggesting that surgery may not uniformly improve long-term cancer outcomes.

“These findings suggest that intensive follow-up is unnecessary for low-risk T1 colorectal cancer after curative ESD,” the authors wrote, adding that the benefit of additional surgery in high-risk disease “remains unclear.”

Key outcomes

For patients with high-risk disease, outcomes differed depending on post-ESD management. The 5-year recurrence rate was 8% in patients managed with follow-up alone versus 2% in those who underwent surgery. Local recurrence occurred in 7% of the follow-up group and 0% of the surgery group.

However, distant recurrence rates were similar between groups, at about 3% with follow-up versus 2% with surgery. Disease-specific survival was also similar, at about 98% in both groups.

Overall survival was lower in the follow-up group (80% vs 95%), although investigators noted that these patients were older and had more comorbidities.

How this could change care

The results may help physicians refine shared decision-making after ESD:

• Low-risk disease: ESD alone appears sufficient, supporting de-escalation of both surgery and surveillance.

• High-risk disease: Surgery clearly reduces local recurrence but may not affect metastatic risk or cancer-specific mortality, making patient selection key.

• Older or comorbid patients: Observation after ESD may be reasonable when surgical risk outweighs potential benefit.

The study enrolled consecutive patients treated with ESD across 11 hospitals in Japan between 2014 and 2018, reflecting real-world clinical practice. The researchers used established pathological criteria associated with lymph node metastasis risk to categorize patients.

Most recurrences occurred within 3 years, particularly in rectal lesions, underscoring the importance of early surveillance in higher-risk patients.

The authors concluded that while additional surgery prevents local recurrence, its broader oncologic benefit remains uncertain, raising the possibility of overtreatment in some patients.

The study received no external funding. The authors reported no disclosures.