Elevated Carcinoembryonic Antigen Research Articles

S3332 An Unusual Case of Aggressive Prostate Cancer With Liver Metastasis in a Patient With Ulcerative Colitis and Total Colectomy

Introduction: Prostate cancer is a relatively slow-growing with 96.8% 5-year survival rate. Less than 7% of patients are found to have aggressive cancer with metastasis to distant sites, such as: bone, lymph nodes, liver and thorax. The incidence of prostate cancer in the 45-54 year age group is merely 7.2% and median age at diagnosis is 67 years. We present a rare case of a 51-year old patient found to have liver metastasis of prostate origin, which was initially thought to be of gastrointestinal origin given elevated Carcinoembryonic Antigen (CEA) and CA 19-9. Case Description/Methods: A 51-year-old male patient with history of ulcerative colitis status post total colectomy thirty years prior, presented with progressive abdominal distension and unintentional twenty pound weight loss over a two month period. Physical exam revealed a mild jaundice, non-tender distended abdomen with palpable hepato-splenomegaly. Routine laboratory revealed normal complete blood count, with liver function elevation: total bilirubin 3.8, direct bilirubin 3, ALP 722, ALT 112, and AST 395. Computed tomography (CT) scan of the abdomen and pelvis without contrast showed findings concerning for metastatic disease with innumerable hepatic mass lesions, and lymphadenopathy. Cancer markers obtained showed normal AFP, however elevated Chromogranin A, CEA and CA 19-9, at 111 ng/mL, 741 ng/mL and 892 ng/mL, respectively. While initially a gastrointestinal origin of cancer was suspected, a liver biopsy was performed which revealed a poorly differentiated adenocarcinoma of prostate origin with positive staining for NKX3.1 and elevated PSA. (Figure) Discussion: Prostate cancer is the second most frequent malignancy in men worldwide and second leading cause of male-cancer related death in the United States, yet has favorable survival rates. The most common tumor marker for prostate carcinoma is serum PSA, however there is no current guideline recommending periodic PSA measurements. Elevated levels of CEA and CA 19-9 in the setting of metastatic prostate cancer have rarely been reported in literature, with merely eight known other cases. Given patient’s underlying history of ulcerative colitis, suspicion for cholangiocarcinoma would have been high on differential and in this case liver biopsy would be contraindicated. Our case highlights a rare presentation of liver metastasis and highlights importance of keeping broad differential. Importantly, liver metastatic burden is of concern and limiting factor when choosing immunotherapy or chemotherapy.Figure 1.: Computed tomography (CT) image of the abdomen, showing innumerable hypodense hepatic mass lesions (white arrows), with the largest in the right hepatic lobe measuring up to 5.4 x 5.0 cm indicated by red arrow.

Elevated CEA and CA 19-9 Levels within the Normal Ranges Increase the Likelihood of CRC Recurrence in the Chinese Han Population.

Objective This study aimed to determine if variations in the expression profiles of CA 19-9 and carcinoembryonic antigen (CEA) within the reference range could serve as possible biomarkers for postoperative CRC recurrence. Method This retrospective cohort investigation enrolled 2,596 cases of CRC that received curative surgery. Serum CEA/CA 19-9 were measured through chemiluminescence immunoassay (CLIA). Results During follow-up (median follow-up = 5.2 years), in total, 837 patients experienced recurrence. The fully adjusted hazard ratios (HRs) were significantly higher, ≥1 standard deviation (±SD), in patients with upregulated CEA/CA 19-9 levels (HRCEA = 7.06; HRCA 19 − 9 = 3.98) than in those with downregulated CEA/CA 19-9 levels. The likelihood of recurrence remained consistently greater in cases of elevated CEA/CA 19-9 levels during sensitivity analyses. Conclusions The findings of this analysis showed that variations in CEA/CA 19-9 expression profiles within the reference range impact CRC recurrence.

Real-world survival of colon cancer after radical surgery: A single-institutional retrospective analysis.

The survival rate for colon cancer after radical surgery has been the focus of extensive debate. To assess the postoperative survival and prognostic factors for overall survival (OS), we collected clinicopathological information for 2,655 patients. The survival time and potential risk factors for OS were analyzed by using Kaplan–Meier curves, Cox proportional hazards models, best subset regression (BSR), and least absolute shrinkage and selection operator (LASSO). The 5-year survival rates of stage I–IV colon cancer were 96.6%, 88.7%, 69.9%, and 34.3%, respectively. Adjuvant chemotherapy improved the survival rate (90.4% vs. 82.4%, with versus without adjuvant chemotherapy, respectively) in stage II patients with high-risk factors. Elevated preoperative carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were significantly associated with worse OS compared with patients without these elevations. Less than 12 versus more than 12 harvested lymph nodes (LNs) affected prognosis (84.6% vs. 89.7%, respectively). Regarding the lymph node ratio (LNR), the 5-year OS rate was 89.2%, 71.5%, 55.8%, and 34.5% in patients with LNR values of 0, 0.3, 0.3–0.7, and >0.7, respectively. We constructed a nomogram comprising the independent factors associated with survival to better predict prognosis. On the basis of these findings, we propose that stage II colon cancer patients without high-risk factors and with both elevated preoperative CEA and CA199 should receive adjuvant therapy. Furthermore, the LNR could complement TNM staging in patients with <12 harvested LNs. Our nomogram might be useful as a new prognosis prediction system for colon cancer patients.

Association of serum Interleukin-8 level with lymph node metastasis and tumor recurrence in gastric cancer.

The level of pretherapeutic serum interleukin-8 (sIL-8) has been demonstrated to correlate with chemoresistance in gastric cancer. However, its clinicopathological significance of sIL-8 in gastric cancer remains unknown. Herein, a total of 335 patients diagnosed with gastric adenocarcinoma were enrolled. The clinicopathological features were collected, and the sIL-8 levels were measured using enzyme-linked immunosorbent assay. The sIL-8 levels ranged from 1.48 pg/ml to 1025.22 pg/ml with > 15.41 pg/ml defined as high according to the receiver operating characteristic analysis. sIL-8 levels were strongly associated with Lauren classification and tumor recurrence. High sIL-8 correlated with lymph node metastasis (LNM) in the intestinal- and diffuse-type tumors and acted as an independent risk factor for LNM in both types. Patients with high sIL-8 levels had worse relapse-free survival than those with low sIL-8 levels. High sIL-8 level was associated with tumor relapse in the intestinal- and diffuse-type tumors, and was also an independent risk factor in the intestinal- and mixed-type tumors. Further analysis revealed that sIL-8 levels were positively associated with LNM and tumor relapse in patients with negative carcinoembryonic antigen (CEA), but not in those with elevated serum CEA levels. In conclusion, this retrospective study demonstrated that the pretherapeutic sIL-8 level has predictive value for LNM and tumor recurrence, and may serve as a potential tumor marker in gastric cancer.

Preoperative serum CA19-9 should be routinely measured in the colorectal patients with preoperative normal serum CEA: a multicenter retrospective cohort study

ObjectiveWhether preoperative serum carbohydrate antigen 19–9 (CA19-9) is an independent prognostic factor and there are interactions of serum CA19-9 with carcinoembryonic antigen (CEA) on the risk of recurrence in colorectal cancer (CRC) patients are still not clarified.MethodsConsecutive patients with CRC who underwent curative resection for stage II-III colorectal adenocarcinoma at five hospitals were collected. Based on Cox models, associations of preoperative CA19-9 with recurrence-free survival (RFS) and overall survival (OS) were evaluated in patients with or without elevated CEA, and interactions between CEA and CA19-9 were also calculated. Restricted cubic spline (RCS) curves were used to evaluate the associations between preoperative CA19-9 and CRC outcomes on a continuous scale.ResultsA total of 5048 patients (3029 [60.0%] men; median [interquartile range, IQR] age, 61.0 [51.0, 68.0] years; median [IQR] follow-up duration 46.8 [36.5–62.4] months) were included. The risk of recurrence increased with the elevated level of preoperative CA19-9, with the slope steeper in patients with normal CEA than those with elevated CEA. Worse RFS was observed for elevated preoperative CA19-9 (> 37 U/mL) (n = 738) versus normal preoperative CA19-9 (≤ 37 U/mL) (n = 4310) (3-year RFS rate: 59.4% versus 78.0%; unadjusted hazard ratio [HR]: 2.02; 95% confidence interval [CI]:1.79 to 2.28), and significant interaction was found between CA19-9 and CEA (P for interaction = 0.001). Increased risk and interaction with CEA were also observed for OS. In the Cox multivariable analysis, elevated CA19-9 was associated with shorter RFS and OS regardless of preoperative CEA level, even after adjustment for other prognostic factors (HR: 2.08, 95% CI:1.75 to 2.47; HR: 2.25, 95% CI:1.80 to 2.81). Subgroup analyses and sensitivity analyses yielded largely similar results. These associations were maintained in patients with stage II disease (n = 2724).ConclusionsPreoperative CA19-9 is an independent prognostic factor in CRC patients. Preoperative CA19-9 can be clinically used as a routine biomarker for CRC patients, especially with preoperative normal serum CEA.

Increased Carcinoembryonic Antigen (CEA) Level Is Highly Associated with Low Skeletal Muscle Mass in Asymptomatic Adults: A Population-Based Study.

We investigated the relationship between high carcinoembryonic antigen (CEA) levels and low skeletal muscle mass (LMM) in asymptomatic adults in a population-based study. A total of 202,602 adults (mean age 41.7 years) without malignancy, stroke, cardiovascular disease, or chronic lung/liver disease were included. A high CEA level was defined as ≥5 ng/mL. Skeletal muscle mass index (SMI) was calculated based on appendicular muscle mass (kg)/height (m)2. Participants were classified into three groups based on SMI: “normal”, “mild LMM”, and “severe LMM.” The prevalence of elevated CEA levels was the highest in subjects with severe LMM (4.2%), followed by those with mild LMM (1.6%) and normal muscle mass (1.1%) (p for trend < 0.001). In multivariate logistic regression analysis, high CEA was independently associated with having mild LMM (adjusted odds ratio, 1.139 [95% confidence interval, 1.092–1.188]) and severe LMM (2.611 [2.055–3.319]) compared to normal muscle mass. Furthermore, the association between high CEA and severe LMM was stronger in women than that in men (women, 5.373 [2.705–10.669]; men, 2.273 [1.762–2.933]). Elevated CEA levels were significantly associated with a higher prevalence of LMM. Therefore, increased CEA could be used as a biomarker for detecting LMM in adults without cancer.

Gallbladder neuroendocrine carcinoma diagnosis, treatment and prognosis based on the SEER database: A literature review.

BACKGROUNDGallbladder neuroendocrine carcinoma (GB-NEC) has a low incidence rate; therefore, its clinical characteristics, diagnosis, treatment and prognosis are not well explored. AIMTo review recent research and analyze corresponding data in the Surveillance Epidemiology and End Results (SEER) database. METHODSData of GB-NEC (n = 287) and gallbladder adenocarcinoma (GB-ADC) (n = 19 484) patients from 1975 to 2016 were extracted from the SEER database. Survival analysis was performed using Kaplan–Meier and Cox proportional hazards regression. P < 0.05 was considered statistically significant. We also reviewed 108 studies retrieved from PubMed and Reference Citation Analysis (https://www.referencecitationanalysis.com/). The keywords used for the search were: "(Carcinoma, Neuroendocrine) AND (Gallbladder Neoplasms)". RESULTSThe GB-NEC incidence rate was 1.6% (of all gallbladder carcinomas), male to female ratio was 1:2 and the median survival time was 7 mo. The 1-, 2-, 3- and 5-year overall survival (OS) was 36.6%, 17.8%, 13.2% and 7.3% respectively. Serum chromogranin A levels may be a specific tumor marker for the diagnosis of GB-NEC. Elevated carcinoembryonic antigen, carbohydrate antigen (CA)-19-9 and CA-125 levels were associated with poor prognosis. Age [hazard ratio (HR) = 1.027, 95% confidence interval (CI): 1.006–1.047, P = 0.01] and liver metastasis (HR = 3.055, 95% CI: 1.839–5.075, P < 0.001) are independent prognostic risk factors for OS. Patients with advanced GB-NEC treated with surgical resection combined with radiotherapy and/or chemotherapy may have a better prognosis than those treated with surgical resection alone. There was no significant difference in OS between GB-NEC and GB-ADC.CONCLUSIONThe clinical manifestations and prognosis of GB-NEC are similar to GB-ADC, but the treatment is completely different. Early diagnosis and treatment are the top priorities.

High Prevalence of Abnormal Carcinoembryonic Antigen in Diabetic Inpatients with Poor Glycemic Control

IntroductionHigher serum carcinoembryonic antigen (CEA) was found in diabetic patients rather than controls. However, the prevalence of abnormal CEA among diabetic inpatients with a large proportion of poor glycemic control is unclear.MethodsA total of 385 diabetic inpatients were included in this study. We collected information from a large clinical database. Patients with malignant tumors were excluded by examination and follow-up.ResultsWe found a surprisingly high prevalence (14.3%) of diabetic inpatients with CEA above normal. The proportion of patients with abnormal CEA was significantly different in subgroups with different blood glucose levels, 20.4% in the HbA1c ≥ 9% group, and 8.5% in the HbA1c < 9%, p = 0.000. We found that the CEA levels were correlated with age, body mass index and HbA1c. The regression coefficient of HbA1c was the highest, B = 0.284, p = 0.000. We also found that the CEA levels were higher in diabetic inpatients with BMI < 24 kg/m2 than the overweight or obesity patients. There was a significant difference in the insulin level and C peptide level between the elevated CEA group and the non-elevated CEA group.ConclusionThe elevation of CEA is common in diabetic inpatients, especially those with poor hyperglycemia controlled (HbA1c ≥ 9%). The underlying mechanism may be related to glucose toxicity.

Prognostic Role of Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 in Stage IV Colorectal Cancer.

We investigated the association of the levels of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) with prognosis in patients with stage IV colorectal cancer at diagnosis. In this multicenter retrospective cohort study, patients with serum CEA and CA19-9 measured at diagnosis of stage IV colorectal cancer were included. The cutoff values were 5 ng/ml for CEA and 37 U/ml for CA19-9. Patients were categorized into four groups: those with normal levels for both CEA and CA19-9; those with only an elevated CEA level; those with only an elevated CA19-9 level; and those with elevated levels of both. A total of 825 patients were included. Among them, 132 (16.0%) had normal levels for both markers, 258 (31.3%) had an elevated CEA level only, 33 (4.0%) had an elevated CA19-9 level only, and 402 (48.7%) had elevated levels of both CEA and CA19-9. Compared with patients with normal levels for both CEA and CA19-9, the multivariate hazard ratio for overall survival was 1.24 (95% confidence interval=0.95-1.62, p=0.12) for those with elevated CEA only, 2.04 (95% confidence interval=1.31-3.17, p=0.002) for those with elevated CA19-9 only, and 1.82 (95% confidence interval=1.41-2.32, p<0.001) in those with elevation of both CEA and CA19-9. Elevation of CEA alone was not prognostic. Elevation of only CA19-9 at diagnosis was associated with a worse prognosis in patients with stage IV colorectal cancer. The combined measurement of CEA and CA19-9 can be helpful as a predictive tool for the prognosis of stage IV colorectal cancer.

Diagnosis of metachronous papillary thyroid cancer with elevated carcino-embryonic antigen levels in tracking rectal carcinoma

Carcinoembryonic antigen (CEA) is a tumor marker that is mostly used to track patients with colorectal cancer (CRC). CEA is an indirect tumor marker that can be useful in both malignant and benign diseases. We presented the case of a 49-year-old man who had been monitored for a lower rectal adenocarcinoma since 2010. In 2010, he had an abdominoperineal resection. Previously completed both neoadjuvant and adjuvant chemo-radiotherapy. In 2019, he was planned to undergo parastomal hernia (PS) repair, but studies have shown elevated CEA levels. The CEA concentration was 27.6 ng/ml. Although there were no signs of recurrence, positron emission tomography (PET) and computed tomography (PET/CT) revealed considerable uptake in the left lobar thyroid. Papillary thyroid carcinoma (PCT) was found on fine needle aspiration cytology (FNAc). He underwent total thyroidectomy and CEA level reached the baseline after thyroidectomy.

A large pancreatic mass in a young adult

A 20-year-old female patient with no significant medical history was referred to us for a large pancreatic mass with a 3-month history of worsening back pain radiating to the epigastrium. She also developed postprandial emesis, early satiety, persistent belching, fatigue, and a 40-pound unintentional weight loss. On exam, her hemodynamic parameters and the abdominal exam were unremarkable. Laboratory values, including blood count, chemistry, and liver function test, were unremarkable except for an elevated carcinoembryonic antigen (31.5 ng/mL).

High Yield of Chest X-ray in the Follow-Up of Colorectal Cancer

Purpose: Worldwide, colorectal carcinoma (CRC) has a high incidence and a substantial cancer-related mortality. The recurrence risk is 30–50% and lung metastases are common. Treatment of lung metastases with stereotactic ablative radiotherapy (SABR) or metastasectomy may increase survival. The best modality for thoracic screening in the follow-up, however, remains controversial. In this study, we aimed to unravel the additional value of routine chest X-ray (CXR) for detecting lung metastases during the follow-up of CRC patients treated with curative surgery. Methods: Between 2013 and 2017, 668 CRC patients were treated with curative intent, of whom 633 patients were included in follow-up, which consisted of CXR, serum Carcino-Embryonic Antigen (CEA) and ultrasound of the liver. Patients who developed lung metastases, diagnosed with CXR and characterised by a normal concomitant serum CEA level, were identified. Number, size and treatment of lung metastases were described. Results: Thirty-four (5.4%) patients developed lung metastases. Seventeen (50%) were detected by CXR without pathological CEA levels. Eleven (65%) of these patients were treated with curative intent, whereas 21% of patients with lung metastases and elevated CEA levels were treated with curative intent (p = 0.049). Higher numbers of lung metastases were associated with a lower chance of curative treatment. Conclusions: More than 50% of patients with lung metastases on CXR in the follow-up would not have been detected with CEA-triggered imaging only. In addition, patients with colorectal lung metastases without elevated CEA levels were often suitable for curative treatment and, therefore, CXR seems to have additional value within the follow-up of CRC.

Elevated serum CEA is associated with liver metastasis and distinctive circulating tumor DNA alterations in patients with castration-resistant prostate cancer.

BackgroundElevated serum carcinoembryonic antigen (CEA) is used to identify “treatment emergent” forms of castration‐resistant prostate cancer (CRPC) such as aggressive variant prostate cancer (AVPC). However, its individual utility as a prognostic marker and the genetic alterations associated with its expression have not been extensively studied in CRPC.MethodsThis study retrospectively analyzed clinical outcomes and circulating tumor DNA profiles in 163 patients with CRPC and elevated or normal serum CEA. These same patients were then classified as AVPC or non‐AVPC and compared to determine the uniqueness of CEA‐associated gene alterations.ResultsPatients with elevated CEA demonstrated higher rates of liver metastasis (37.5% vs. 19.1%, p = 0.02) and decreased median overall survival from CRPC diagnosis (28.7 vs. 73.2 mo, p < 0.0001). In addition, patients with elevated CEA were more likely to harbor copy number amplifications (CNAs) in AR, PIK3CA, MYC, BRAF, CDK6, MET, CCNE1, KIT, RAF1, and KRAS. Based on variant allele frequency we also defined “clonal” single‐nucleotide variants (SNVs) thought to be driving disease progression in each patient and found that CEA expression was negatively correlated with clonal AR SNVs and positively correlated with clonal TP53 SNVs. Of these genetic associations, only the increases in clonal TP53 SNVs and KRAS amplifications were recapitulated among patients with AVPC when compared to patients without AVPC.ConclusionsTogether these findings suggest that CEA expression in CRPC is associated with aggressive clinical behavior and gene alterations distinct from those in AVPC.

MSR37 Methods for Recovering Missing Longitudinal Biomarker Values from Electronic Health Record Data

Longitudinal biomarker values in EHR data measure patient health and are typically correlated with important adverse events. These data can be valuable in healthcare research (e.g. risk prediction) but are often subject to a high degree of missingness. We develop an imputation approach that leverages and preserves the relationship of the biomarker with adverse events. We demonstrate our approach using carcinoembryonic antigen (CEA) biomarker values in the setting of colorectal cancer (CRC) surveillance, where elevated CEA is associated with recurrence.

Significance of serum carcinoembryonic antigen in metastatic breast cancer patients: A prospective study.

BACKGROUNDCarcinoembryonic antigen (CEA) is an important serum tumour marker with a substantial role in diagnosis and monitoring of various solid tumours. About 36%-70% of breast cancers have elevated serum CEA. And the available studies show discrepancy in addressing the prognostic significance of CEA in advanced breast cancer.AIMTo estimate the serum CEA level in our metastatic breast cancer patients and correlate it with response to treatment and clinical outcome.METHODSThis was a prospective clinical study conducted on 50 metastatic breast cancer patients treated at breast clinic, with newly diagnosed metastatic breast cancer planned for palliative chemotherapy, targeted therapy, and hormonal treatment. We estimated the proportion of patients with elevated serum CEA level at baseline and after palliative treatment and also studied the association of serum CEA levels with known prognostic factors. The response to treatment was correlated with the serum CEA levels in the context of responders and non-responders.RESULTSThe median pre-treatment and post-treatment CEA levels were 7.9 (1.8-40.7) ng/mL and 4.39 (1.4-12.15) ng/mL, respectively, in the whole study population (P = 0.032). No statistically significant difference was seen in baseline serum CEA between responders and non-responders. Even in the luminal group, pre-treatment serum CEA was not a predictor of response, but post-treatment CEA was a significant predictor of tumour progression. In patients with liver and lung metastases, post-treatment CEA level difference was not statistically significant in both responders and non-responders though the values were higher in non-responders. Among those with bone metastases, 69.5% had elevated post-treatment serum CEA, and only 37.5% had elevated serum CEA in those with no bone metastases.CONCLUSIONElevated post-treatment serum CEA levels are associated with disease progression and poor response to therapy. Persistently elevated post-treatment serum CEA levels are significantly associated with bone metastases. Elevated serum CEA and hormonal status are significant predictors of treatment response.

Pre- and Postoperative Levels of Carcinoembryonic Antigen in Microsatellite Stable Versus Instable Colon Cancer: a Retrospective Analysis.

The prognosis of microsatellite stable (MSS) versus instable (MSI) tumors is an ongoing matter of debate, with differences in expression of carcinoembryonic antigen (CEA) in these two tumor subsets being inconsistently reported to date. The aim of this study was to investigate CEA expression in the context of clinical parameters in MSS and MSI tumors. Clinical, pathological, and biochemical parameters of colon cancer patients who underwent curative surgery were documented in a database and compared between MSS and MSI cases. The pre- to postoperative trend of CEA was analyzed. Survival was assessed using the Kaplan-Meier (log rank) test. One hundred sixty-nine patients were included in the study. Compared to those with MSS tumors, there was a higher proportion of preoperatively elevated CEA among those with MSI tumors (p = 0.067). Median CEA values decreased over the pre- to postoperative course with MSS (p = 0.01) but not MSI (p = 0.093) tumors. The distribution of N classification differed between MSS and MSI tumors (p = 0.014). Patients with MSI tumors had superior survival. Despite the better prognosis, MSI tumors are associated with increases in CEA. Our findings shed light on discrepancies related to the prognostic evaluation of MSI tumors. Furthermore, in follow-up of colorectal cancers, CEA measurements should be interpreted differently for MSI and MSS tumors.

A Case of a Gastric Lesion With a Hypoechoic Area in the Submucosa

Question: A 62-year-old man was referred to our hospital for slightly elevated carcinoembryonic antigen. He had a history of chronic obstructive pulmonary disease. Physical examination was unremarkable, and blood tests showed a carcinoembryonic antigen of 4.7 ng/mL, carbohydrate antigen 19-9 of 7.9 U/mL, and a high Helicobacter pylori antibody level of 24 U/mL. Chest and abdominal computed tomography scans showed no malignancies. Esophagogastroduodenoscopy revealed a 10-mm elevated lesion with fading color change on the posterior wall of the upper body of the stomach (Figure A).

Elevated Carcinoembryonic Antigen at the Time of Recurrence as a Poor Prognostic Factor in Colorectal Cancer: A Propensity Score Matching Analysis

There are few studies on the prognostic impact of CEA level at the time of recurrence in recurrent colorectal cancer. The objective of this study was to evaluate the prognostic value of serum CEA levels at the time of recurrence in patients with recurrent colorectal cancer. Between 2007 and 2014, 962 consecutive recurrent patients for colorectal cancer were analyzed. These patients were divided into two groups according to CEA level at the time of recurrence (r-CEA): high r-CEA (≥5 ng/ml) (n = 428) and normal r-CEA (<5 ng/ml) (n = 534). The prognostic effects of r-CEA were evaluated by one-to-one propensity score matching (PSM) to adjust factors between groups. After matching, a total of 778 patients, 389 per group, were analyzed. After matching, the 5-year disease-free survival rate for the high r-CEA group was significantly lower than that for the normal r-CEA group. The 5-year overall survival rate was 56.5% in the high r-CEA group and 66.0% in the normal r-CEA group (p = 0.008). The 5-year cancer-specific survival rate was 61.7% in the high group and 67.5% in the normal group (p = 0.035). In a multivariate analysis of prognostic factors, high preoperative CEA level at the time of recurrence, poor histologic grade, and lymphatic invasion were associated with poorer overall survival. The high r-CEA level group showed significantly poorer prognosis than the normal r-CEA group. Therefore, the r-CEA level can be used as a prognostic factor in recurrent colorectal cancer. Aggressive adjuvant treatment needs to be considered for patients with an initially high CEA level and lymph node positivity who are prone to recurrence.

Total neoadjuvant treatment approach and carcinoembryonic antigen level in locally advanced rectal cancer.

e15595 Background: Total Neoadjuvant therapy (TNT) has gained acceptance in the treatment of locally advanced rectal cancer, although the optimal sequencing of therapy chemoradiation (CRT) followed by consolidation chemotherapy (cChT) or induction chemotherapy followed by chemoradiation (iChT), remains a subject of ongoing debate. The effect of TNT sequencing and carcinoembryonic antigen (CEA) level on progression free survival (PFS) is uncertain. We conducted a retrospective analysis to examine these issues. Methods: Patients (n = 44) with locally advanced rectal cancer from June 2016 to December 2020 were reviewed. CEA level was compared against the primary outcome of response to TNT approaches. We categorized patients into 3 groups based on pre-TNT and post-TNT (i.e. pre-surgical) CEA: normal CEAPRE/normal CEAPOST, elevated CEA PRE/normal CEA POST, elevated CEA PRE/elevated CEA POST. 3-Year PFS was calculated using Kaplan-Meier method. Univariable and multivariable logistic regression analyses identified characteristics predictive of PFS and clinicopathologic variables associated with TNT sequencing. Results: The study cohort had a median age of 61 years and was predominantly male (70%) and Caucasian (94%). Pre-treatment stage was either II (27%) or III (72%), with the majority (65%) undergoing iChT. Downstaging occurred in 42/44 (95%). Baseline CEA was elevated in 40.9% of patients. On multivariable, logistic regression variable associated with receipt of CRT followed by cChT included: Age &gt; 61 years clinical T4 disease and lack of T downstaging (p &lt; 0.05 for all).There was no difference in 3-year PFS between patients receiving iChT versus patients receiving cChT (p = 0.53). When patients were stratified according to pretreatment CEA level, no difference in 3 year PFS were noted (p = 0.46). On multivariable analysis, lack of nodal downstaging following neoadjuvant treatment was associated with higher likelihood of progression (p = 0.02). Similarly, pretreatment CEA &gt; 4.25 ng/ml (p = 0.08) and failure of CEA to decrease by &gt;2 ng/ml following TNT (p = 0.07) trended toward higher likelihood of progression. Conclusions: Neither TNT sequencing, nor baseline CEA predicted the PFS although the power of our study was limited. Lack of nodal downstaging was identified as a predictor of worse PFS. Further areas of study should include plasma-based assays to quantitate circulating tumor DNA and next generation sequencing to assess prognosis with different sequencing of TNT.

P-301 Pre-surgical carcinoembryonic antigen as a recurrence biomarker in stage III colon cancer treated with adjuvant chemotherapy in a Latin American center

Colorectal cancer represents the third most incident malignant neoplasm in the world and the second in terms of mortality. In Peru, colon cancer is positioned as the fifth malignant neoplasm in terms of incidence and the sixth, in terms of mortality(1). Surgery continues to be the curative therapy for this pathology, however, the risk of disease recurrence is still a subject of study, as well its association with risk factors, such as the degree of tumor invasion (T) and lymph node involvement (N)(2). Likewise, the role of other factors has been shown to have prognostic relevance in colon cancer patients(3,4). The main objective of this research was to determine if the preoperative carcinoembryonic antigen (CEA) level is a prognostic biomarker of recurrence and survival in patients with stage III colon cancer. A cross-sectional descriptive study was carried out, between the years 2013 and 2018, 1987 patients with colon cancer were analyzed, of which 162 patients were stage III and received adjuvant treatment with chemotherapy based on fluoropyrimidines and who complied with the inclusion criteria. The preoperative CEA level was studied (cutoff point 5); secondarily, the following clinicopathological characteristics were evaluated: age ( 45 years), albumin level ( 35 g/L), location of the primary colon (right colon vs. left colon), lymphovascular invasion (present, absent), perineural invasion (present, absent), histological grade (1, 2 or 3). The mean age was 63.7 years, 63 patients were women (38.9%), 99 patients were men (61.1%). Univariate analysis showed that the level of CEA > 5 is statistically significant (p=0.005) for recurrence. Likewise, the multivariate analysis maintained the finding of a CEA level > 5 (HR 2.71, 95%IC [1.25-5.85], p=0.011) as a prognostic factor for recurrence. Median follow-up for disease-free survival (DFS) was 31.36 months. Median DFS was not reached in either group. The DFS at 3 years in the group with CEA 5. The evaluation of the other clinicopathological characteristics were not significant. As well, it was possible to determine that the majority of recurrence cases, in the group of patients with CEA > 5, were in the first two years with a total of 18 of 21 events (85.71%). In patients with stage III colon cancer who have received adjuvant therapy, a CEA level greater than 5 has a negative impact on disease-free survival. Likewise, the greatest risk for presenting recurrence, in patients with elevated CEA, is seen in the first 2 years.