Carcinoembryonic antigen has prognostic value for tumor downstaging and recurrence in rectal cancer after preoperative chemoradiotherapy and curative surgery: A multi-institutional and case-matched control study of KROG 14-12

• Published in: Radiotherapy and oncology 2015-08, Vol.116 (2), p.202-208
• Main Authors: Lee, Jong Hoon, Kim, Dae Yong, Kim, Sung Hwan, Cho, Hyeon Min, Shim, Byoung Yong, Kim, Tae Hyun, Kim, Sun Young, Baek, Ji Yeon, Oh, Jae Hwan, Nam, Taek Keun, Yoon, Mee Sun, Jeong, Jae Uk, Kim, Kyubo, Chie, Eui Kyu, Jang, Hong Seok, Kim, Jae-Sung, Kim, Jin Hee, Jeong, Bae Kwon
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - pathology; Adenocarcinoma - therapy; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Capecitabine - administration & dosage; Carcinoembryonic Antigen - metabolism; CEA; Chemoradiotherapy; Chemoradiotherapy - methods; Combined Modality Therapy; Epidemiologic Methods; Female; Fluorouracil - administration & dosage; Health Facilities; Hematology, Oncology and Palliative Medicine; Humans; Male; Middle Aged; Neoplasm Recurrence, Local - pathology; Neoplasm Staging; Preoperative Care; Prognosis; Rectal cancer; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Recurrence; Response; Treatment Outcome
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2015.07.049

Abstract Background and purpose The Korean Radiation Oncology Group evaluated the significance of carcinoembryonic antigen (CEA) levels both as a predictor of tumor response after CRT and as a prognosticator for recurrence-free survival. Methods and materials 1804 rectal cancer patients, staged cT3–4N0–2M0, participated in a multicenter study. The patients were administered preoperative radiation of 50.4 Gy in 28 fractions with 5-FU or capecitabine, followed by total mesorectal excision. Patients with elevated CEA levels (>5 ng/mL) were matched at a 1 ( n = 595):1 ( n = 595) ratio with patients with normal CEA (⩽5 ng/mL). The tumor response after CRT and the recurrence-free survival (RFS) rates were evaluated and compared between two arms. Results An elevated CEA level ( p < 0.001) was determined to be a significant negative predictor of downstaging after CRT. The downstaging rate was 42.9% for normal CEA and 23.4% for elevated CEA. A multivariate analysis also revealed that cT ( p = 0.021) and cN classification ( p = 0.001), tumor size ( p = 0.002), and tumor location from the anal verge ( p = 0.006) were significant predictors for tumor downstaging. The 5-year RFS rates were significantly higher for the normal CEA arm than for the elevated CEA arm (74.2 vs. 63.5%, p < 0.001). Conclusions Elevated CEA (>5 ng/mL) is a negative predictor of tumor downstaging after CRT and also has a negative impact on RFS in rectal cancer.