CEA - a predictor for pathologic complete response after neoadjuvant therapy for rectal cancer.

Area of Science:

• Oncology
• Gastroenterology
• Surgical Oncology

Background:

• Preoperative chemoradiation therapy (CRT) for rectal cancer yields pathologic complete response (pCR) in 10-30% of patients.
• Identifying predictive factors for pCR can guide treatment selection, potentially avoiding radical surgery for select patients.

Purpose of the Study:

• To evaluate the impact of tumor characteristics, patient factors, and pretreatment CEA levels on pCR after neoadjuvant CRT.
• To identify predictors of pCR in locally advanced rectal cancer.

Main Methods:

• Retrospective review of 469 rectal adenocarcinoma patients treated with preoperative CRT and radical surgery (1998-2011).
• Analysis included tumor size, stage, location, CEA levels, and treatment interruptions.
• Pathologic complete response (pCR) was the primary outcome measure.

Main Results:

• 20% of patients achieved pCR.
• Lower pretreatment CEA levels (p=0.008) and smaller tumor size (p=0.02) were associated with pCR.
• Multivariate analysis identified low CEA and CRT interruption as significant predictors of pCR.
• Low CEA predicted pCR in nonsmokers but not in smokers.

Conclusions:

• Low pretreatment CEA levels and CRT interruption are associated with pCR in rectal cancer.
• The predictive value of CEA for pCR may be limited in smokers.
• Further research is needed to clarify the role of smoking in CEA's predictive capacity for rectal cancer pCR.