2020
Tânia Gago, Paulo Caldeira, Joana Roseira, Catarina Cunha, Pedro Campelo, Horácio Guerreiro
Gastroentérologie – 2020-07-04 – CO –
________________________________
Introduction: The carcinoembryonic antigen (CEA) is a preoperative biomarker commonly used in patients with colorectal cancer (CRC). However, controversy still exists regarding its prognostic value in CRC. Recent studies have found that local CEA may play a more important role in the prognosis of CRC than overall serum CEA.
Aims: We aimed to investigate whether the preoperative serum CEA/maximum tumor diameter (CEA/TS) serves as a prognostic factor in patients with rectal adenocarcinoma who received neoadjuvant chemoradiation therapy (NA-CRT) followed by curative tumor resection. The outcomes were downstaging (clinical stage higher than pathologic stage), complete pathologic response (no viable tumor cells in either the rectal wall or lymph nodes on pathology of the surgical resection specimen (ypT0N0M0)), overall survival (OS) (time in months from surgery to death) and disease-free survival (DFS) (time from surgery to disease recurrence).
Methods: We retrospectively reviewed patients with rectal cancer who underwent NA-CR followed by curative tumor resection from march 2012 to october 2017. Both preoperative serum CEA level and the rectal tumor size were assessed to calculate CEA/ExT, which represents the CEA level adjusted by tumor size. All analyses were performed using Statistical Package for the Social Sciences (version 24.0).
Results: In all, 89 patients who satisfied both the inclusion and exclusion criteria were included: 60,7% males, overall median age of 63,8±10,42 years, and 79,8% patients with Eastern Cooperative Oncology Group Performance Status of 0. In the majority of them the tumor was located in distal rectum (43,8%) and measured less than 5 cm (57,3%). In 58,4% patients, surgery was performed between 6 and 10 weeks after NA-CRT. There was downstaging in 83,1% patients and complete pathologic response in 41,6% patients. The mean CEA/ExT was 2,01ng/ml per cm. The univariate analysis indicated that higher CEA/ExT levels were associated with high CA 19-9 level (p=0,04) and low hemoglobin (p=0,03), complete pathologic response (p=0,04) and downstaging (p=0,02). According to the multivariate analysis, CEA/ExT was independently associated with downstaging (OR: 5,60; 95%CI: 1.14-26.9, p=0.03). Likewise, patients with low CEA/ExT had better OS and DFS.
Conclusion: Preoperative CEA/ExT can be used to predict the outcomes of patients with rectal cancer who underwent NA-CRT which may influence the decision-making process for a specific treatment regimen and patient counselling.