A patient with a T2N0 mid-rectal cancer (8 cm from anal verge) is considered for transanal excision versus radical resection. According to ACOSOG Z6041 trial findings, which feature MOST strongly predicts residual or recurrent disease after local excision with chemoradiation?

• A Tumor size greater than 3 cm
• B Poor differentiation on pre-treatment biopsy
• C Preoperative CEA greater than 5 ng/mL
• D Close or positive histological margins after local excision ✓

Explanation

The ACOSOG Z6041 trial evaluated neoadjuvant chemoradiation followed by transanal excision (local excision) for T2N0 rectal cancer. The strongest predictor of residual or recurrent disease was positive or close resection margins at transanal excision, emphasizing the critical importance of achieving R0 resection even in organ-sparing approaches. While tumor size, differentiation, and CEA are relevant risk factors, margin status directly determines local recurrence risk and need for salvage radical resection. The trial showed 3-year DFS of 88.2% when margins were clear.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.