P0066 Pretreatment serum carcinoembryonic antigen levels are associated with chemoradiation-induced downstaging and downsizing of rectal cancer. (July 2015)

• Record Type: Journal Article
• Authors: Kim, M.-J.; Kim, E.S.; Min, C.K.; Yeo, S.-G.
• Is Part Of: European journal of cancer. Volume 51(2015)Supplement 2
• Page Start: e14
• Page End: e15
• Publication Date: 2015-07
• Subjects: Cancer -- Periodicals; Neoplasms -- Periodicals; Cancer -- Périodiques; Cancer; Tumors; Electronic journals; Periodicals; Electronic journals; 616.994
• DOI: 10.1016/j.ejca.2015.06.045
• Languages: English
• ISSNs: 0959-8049

Abstract

Abstract : Background: Multimodality management of patients with locally advanced rectal cancer (LARC) can be individualised according to their predicted responses to chemoradiotherapy. This study aimed to identify pretreatment clinical parameters that are associated with preoperative chemoradiotherapy-induced downstaging and downsizing of LARC. Methods: 51 patients with LARC (T3-4, or N+) receiving preoperative chemoradiotherapy between 2010 and 2013 were retrospectively analysed. All patients had histologically confirmed adenocarcinoma. The median age was 64 years, ranging from 41 to 81 years. Chemoradiotherapy consisted of 50.4 Gy pelvic radiotherapy plus concurrent chemotherapy (using fluorouracil and leucovorin). After a median 7 weeks since completing their chemoradiotherapy regimen, patients underwent total mesorectal excision. Downstaging was defined as a transition from cStage 2–3 to ypStage 0–1. The longest tumour diameter was measured on computed tomography or magnetic resonance imaging (before treatment) and by surgical specimen (after chemoradiotherapy). Pretreatment parameters analysed for an association with downstaging or downsizing included age, sex, tumour location, cT/cN stage, tumour size, serum carcinoembryonic antigen (CEA) levels, haemoglobin levels, intervals between chemoradiotherapy and surgery, and maximum standardised uptake value (mSUV) on positron emission tomography. Findings: Downstaging occurred in 16 (31.4%) patients, including five (9.8%) patients with a pathological complete response. Median downsizing of patient tumours was 60% (range 0–100) and downsizing of more than 60% was reported in 25 (49%) patients. Serum CEA levels ranged from 0.8 to 153.9 (median 4.4) ng/ml. The mSUV ranged from 4.7 to 33.9 (median 10.8). Use of a univariate analysis showed cT stage, tumour size, and CEA were associated with downstaging. Use of a multivariate analysis showed that only CEA levels (⩽5 ng/ml) were a significant factor to predict downstaging (odds ratio 16.0, 95% CI 1.8–146.7; p = 0.014). CEA levels were found to be the only factor significantly associated with downsizing in univariate analysis. Interpretation: This study showed that pretreatment levels of serum CEA were significantly associated with both downstaging and downsizing of LARC after preoperative chemoradiotherapy. Pretreatment levels of serum CEA are valuable parameters to implement personalised treatments for patients with LARC.