Diagnostic accuracy of serum-carcinoembryonic antigen in recurrent colorectal cancer: a receiver operating characteristic curve analysis

Prognostic prediction model of colorectal cancer based on preoperative serum tumor markers

BACKGROUND

Preoperative serum tumor markers not only play a role in the auxiliary diagnosis and postoperative monitoring in colorectal cancer (CRC), but also have been found to have potential prognostic value.

AIM

To analyze whether preoperative serum tumor markers, including carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), affect the prognosis of CRC.

METHODS

This was a retrospective study conducted in a single center. Patients with nonmetastatic CRC who underwent initial surgery between January 2011 and January 2020 were enrolled and divided into development site and validation site groups at a ratio of 7:3. The independent prognostic factors were screened by Cox regression analysis, and finally, a prognostic nomogram model was established. The newly developed model was tested by internal validation.

RESULTS

Eventually, 3526 postoperative patients with nonmetastatic CRC were included in the study. There were 2473 patients at the development site and 1056 patients at the validation site. Age (P < 0.01, HR = 1.042, 95%CI = 1.033-1.051), tumor node metastasis (TNM) classification (P < 0.01, HR = 1.938, 95%CI = 1.665-2.255), preoperative CEA (P = 0.001, HR = 1.393, 95%CI = 1.137-1.707) and CA19-9 (P < 0.01, HR = 1.948, 95%CI = 1.614-2.438) levels were considered independent prognostic factors for patients with nonmetastatic CRC and were used as variables in the nomogram model. The areas under the curve of the development and validation sites were 0.655 and 0.658, respectively. The calibration plot also showed the significant performance of the newly established nomogram.

CONCLUSION

We successfully constructed a nomogram model based on age, TNM stage, preoperative CEA, and CA19-9 levels to evaluate the overall survival of patients with nonmetastatic CRC.

Tumor Marker Trajectories and Survival Analysis in Patients With Normal Carcinoembryonic Antigen Ranges After Colorectal Cancer Resection

BACKGROUND

Evidence regarding postoperative CEA for predicting long-term outcomes of colorectal cancer remains controversial, especially in patients with normal postoperative CEA.

OBJECTIVE

To investigate the risk difference among different postoperative CEA trajectories in patients with normal postoperative CEA after curative colorectal cancer resection.

DESIGN

This cohort study was conducted at a comprehensive cancer center and included data retrieved from a prospectively collected database between January 2006 and December 2018.

SETTINGS

Retrospective cohort study.

PATIENTS

Patients with colorectal cancer who underwent surgery for primary stage I to III colorectal adenocarcinoma were included and those with postoperative CEA >5 ng/mL were excluded.

INTERVENTIONS

Standard curative radical resection was performed.

MAIN OUTCOME MEASURES

Ten-year overall survival and disease-free survival were analyzed.

RESULTS

The study population (n = 8156) was categorized into 6 trajectories: persistent-ultralow (n = 2351), persistent-low (n = 2474), gradually decrease (n = 401), persistent-medium (n = 1727), slightly increase (n = 909), and around-upper-limit (n = 394). The median follow-up time was 7.8 years, and the median time frame in which CEA was measured to determine trajectory was 2.6 years. The persistent-ultralow group had the highest 10-year overall survival (85.1%) and disease-free survival (82.7%). The around-upper-limit group had the lowest 10-year overall survival (55.5%) and disease-free survival (53.4%). The adjusted HR trend was comparable to the crude HR of the persistent-ultralow group. Consequently, the higher initial serum CEA groups had higher HRs of overall survival and disease-free survival. The adjusted HR of overall survival was 2.96 (95% CI, 2.39-3.66) and of disease-free survival was 2.66 (95% CI, 2.18-3.69) for the around-upper-limit groups.

LIMITATIONS

Retrospective design.

CONCLUSIONS

The postoperative serum CEA trajectory is an independent factor associated with long-term outcomes. Although CEA levels were all within normal range, higher levels of postoperative serum CEA trajectory correlated with worse long-term oncological outcomes. See Video Abstract.

TRAYECTORIAS DE MARCADORES TUMORALES Y ANLISIS DE SUPERVIVENCIA EN PACIENTES CON RANGOS NORMALES DE ANTGENO CARCINOEMBRIONARIO POSTERIOR A RESECCIN DE CNCER COLORRECTAL

ANTECEDENTES:La evidencia sobre el CEA post operatorio para la predicción de los resultados a largo plazo del cáncer colorrectal sigue siendo controversial, especialmente en pacientes con CEA post quirúrgico normal.OBJETIVO:Investigar la diferencia de riesgo entre diferentes trayectorias postoperatorias del CEA en pacientes con CEA post quirúrgico normal tras la resección curativa del cáncer colorrectal.DISEÑO:Este estudio de cohorte se realizó en un centro oncológico integral e incluyó datos recuperados de una base de datos recopilada prospectivamente entre enero de 2006 y diciembre de 2018.AJUSTES:Estudio de cohorte retrospectivo.PACIENTES:Se incluyeron pacientes con el diagnostico de CCR que fueron sometidos a cirugía por adenocarcinoma colorrectal primario en estadio I-III. Se excluyeron pacientes con CEA postoperatorio >5 ng/mL.INTERVENCIONES:Se realizó una resección radical curativa estandarizada.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron la supervivencia general a diez años y la supervivencia libre de enfermedad.RESULTADOS:La población de estudio (n = 8156) fue clasificada en seis trayectorias, que incluyeron ultrabajo persistente (n = 2351), bajo persistente (n = 2474), disminución gradual (n = 401), medio persistente (n = 1727), aumento leve (n = 909) y alrededor del límite superior (n = 394). La mediana del tiempo de seguimiento fue de 7,8 años y la mediana del período de tiempo en el que el CEA fue medido para determinar la trayectoria fue de 2,6 años. El grupo ultrabajo persistente tuvo la mayor supervivencia general a 10 años (85,1 %) y supervivencia libre de enfermedad (82,7 %). El grupo alrededor del límite superior tuvo la supervivencia general a 10 años más baja (55,5 %) y la supervivencia libre de enfermedad (53,4 %). La tendencia del índice de riesgo ajustado fue comparable al índice de riesgo bruto del grupo ultrabajo persistente. En consecuencia, los grupos con CEA sérico iniciales más altos tenían índices de riesgos más altos de supervivencia general y supervivencia libre de enfermedad. Los índices de riesgos ajustados de supervivencia general/supervivencia libre de enfermedad fueron 2,96/2,66 (intervalo de confianza del 95 %: 2,39-3,66/2,18-3,69) para los grupos cercanos al límite superior.LIMITACIONES:El estudio estuvo limitado por su diseño retrospectivo.CONCLUSIONES:La trayectoria del CEA sérico postoperatorio es un factor independiente asociado con resultados a largo plazo. Aunque los niveles de CEA se encontraban todos dentro del rango normal, los niveles más altos de trayectoria del CEA en suero posoperatorio se correlacionaron con peores resultados oncológicos a largo plazo. (Traducción-Dr Osvaldo Gauto ).

Prognostic Value of Combined LMR and CEA Dynamic Monitoring in Postoperative Colorectal Cancer Patients

Purpose

We aim to investigate the clinical significance of dynamic changes in the lymphocyte-to-monocyte ratio (LMR) and neutrophil-lymphocyte ratio (NLR) in peripheral blood at different time points combined with CEA in the prediction of postoperative-recurrence-in-patients with colorectal cancer (CRC).

Patients and Methods

This study collected 357 patients with stage I-III CRC between 2016 and April 2018. The dynamic changes from preoperative to postoperative LMR (p-LMR-p) and NLR (p-NLR-p) were analyzed using COX regression for multivariate analysis. Logistic regression was used to investigate whether the dynamic changes from post-treatment to pre-end of follow-up LMR (p-LMR-f) and NLR (p-NLR-f) were independent risk factors for CRC recurrence and to construct a predictive model. Internal validation using bootstrapping was performed to validate the discrimination ability of the model. The models' discriminative effect, calibration degree, and clinical utility were assessed.

Results

In both the total cohort and the adjuvant therapy group, the dynamic changes of p-LMR-p (High-High vs Low-Low: p=0.006; HR:2.210, 95% CI: 1.256-3.890) were found to be independent prognostic factors for recurrence-free survival (RFS) in CRC patients. Additionally, logistic regression analysis revealed that N stage, CEA, LMR of pre-end of follow-up (f-LMR), and p-LMR-f were independent risk factors for CRC recurrence. In the total cohort, the p-LMR-f had an area under the curve (AUC) of 0.704, with a sensitivity of 64% and a specificity of 75.3%. By combining p-LMR-f with CEA, a predictive model was constructed, which showed an AUC of 0.913 (0.986-0.913) in the total cohort and an AUC of 0.924 (0.902-0.924) in the adjuvant therapy group during internal validation using bootstrapping.

Conclusion

Dynamic changes in LMR can be used to predict the prognosis of CRC and serve as a biomarker for predicting CRC recurrence. Combined with CEA, it can improve the predictive performance for detecting CRC recurrence.

SPATA18 Expression Predicts Favorable Clinical Outcome in Colorectal Cancer

Dysregulation of mitochondrial quality control has been reported to be associated with cancer and degenerative diseases. SPATA18 (spermatogenesis-associated 18, also known as Mieap) encodes a p53-inducible protein that can induce lysosome-like organelles within mitochondria that eliminate oxidized mitochondrial proteins and has tumor suppressor functions in mitochondrial quality control. In the present study, 268 primary colorectal cancers (CRCs) were evaluated immunohistochemically for SPATA18 expression to assess its predictive utility and its association with cellular proliferation activity. Furthermore, the association with p53 immunoreactivity, a surrogate marker for TP53 mutation, was analyzed. Non-neoplastic colonic mucosa showed cytoplasmic SPATA18 expression. Seventy-two percent of the lesions (193/268) displayed high SPATA18 expression in the cytoplasm of CRC cells. Univariate analyses revealed significant associations between SPATA18 expression and tumor size (p < 0.0001), histological differentiation (p = 0.0017), and lymph node metastasis (p = 0.00039). The log-rank test revealed that patients with SPATA18-high CRCs had significantly better survival than SPATA18-low patients (p < 0.0001). Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio [HR] = 0.25), age < 70 years (HR = 0.50), and SPATA18-high (HR = 0.55) as potential favorable factors. Lymph node metastasis (HR = 1.98) and peritoneal metastasis (HR = 5.45) were cited as potential independent risk factors. Cellular proliferation activity was significantly higher in SPATA18-high tumors. However, no significant correlation was detected between SPATA18 expression and p53 immunoreactivity or KRAS/BRAF mutation status. On the basis of our observations, SPATA18 immunohistochemistry can be used in the prognostication of CRC patients.

Why recurrence was initially suspected during colorectal cancer postoperative surveillance?: A retrospective analysis

Routine postoperative surveillance is recommended for the patients with colorectal cancer (CRC). This study aimed to clarify the conditions indicate initial suspicion of CRC recurrence in different preoperative serum carcinoembryonic antigen (CEA) level groups, including positive physical signs/symptoms, elevated CEA level, positive radiologic studies results, and other elevated tumor markers.A total of 2268 patients with recurrence after curative surgery for CRC were enrolled in this study. The patients were classified into 3 groups according to preoperative serum CEA level (low, <2 ng/mL; intermediate, ≥2 and <5 ng/mL; and high, ≥5 ng/mL).Up to 63.6% of recurrence was suspected based on elevated CEA level in the high preoperative serum CEA level group. Patients in the low preoperative serum CEA level group had a higher rate of initial suspicion of recurrence based on positive physical signs or symptoms (36.7% vs 26.9% vs 20.4%, P < .001) and positive radiologic findings (51.4% vs 40.7% vs 29.5%, P < .001) than those in the intermediate and high preoperative serum CEA groups.Conditions indicate initial suspicion of recurrence varied in the different preoperative serum CEA level groups. In patients with low preoperative serum CEA level, the detection of recurrence depend on abnormal CEA level is less sensitive than intermediate and high preoperative serum CEA groups. We suggest that the strategy for CRC surveillance should not depend on serum CEA level alone. The signs or symptoms of patients, changes in postoperative serial CEA level, and ongoing radiologic or imaging findings must be cautiously monitored.

Predictive Early Recurrence Factors of Preoperative Clinicophysiological Findings in Pancreatic Cancer

Background: We aimed to evaluate the use of preoperative clinicophysiological parameters as predictive risk factors for early recurrence of pancreatic ductal adenocarcinoma (PDAC) after curative resection. Methods: A total of 260 patients who underwent pancreatic resection for PDAC between 2007 and 2015 were examined retrospectively. We divided the patients into those with early recurrence (within 6 months; group A, n = 52) and those with relapse within ≥6 months or without recurrence (group B, n = 208). Data regarding clinicophysiological parameters were analyzed as predictors of disease-free survival (DFS). These factors were analyzed by χ2 tests on univariate analysis and Cox proportional hazard models on multivariate analyses. Kaplan-Meier survival curves were generated using log-rank tests. Results: Groups A and B had significantly different preoperative carbohydrate antigen 19-9 (CA19-9) levels, carcinoembryonic antigen (CEA) levels, and curability. Univariate and multivariate analysis showed that CA19-9 and CEA were independent prognostic factors for early recurrence. Patients with CA19-9 levels > 124.65 U/mL had significantly shorter DFS than those with lower levels, as did patients with CEA levels > 4.45 ng/mL. Conclusions: Our results show that elevated CA19-9 (> 124.65 U/mL) and CEA (> 4.45 ng/mL) were independent predictors of early recurrence after pancreatic resection in PDAC patients.

Validation of Assaying Carcinoembryonic Antigen in Human Serum by Using Immunomagnetic Reduction

Immunomagnetic reduction (IMR) is a method to assay biomolecules by utilizing antibody functionalized magnetic nanoparticles. For clinical validation, important analytic performances of assaying carcinoembryonic antigen (CEA) using IMR are characterized. Furthermore, IMR is applied to assay carcinoembryonic antigen (CEA) in human serum for clinical validation. A total of 118 healthy controls and 79 patients with colorectal cancer (CRC) are recruited in this study. For comparison, assays using chemiluminometric immunoassay (CLIA) are also done for quantizing CEA in these serum samples. The results reveal a high correlation in terms of serum CEA concentration detected via IMR and CLIA is found (r = 0.963). However, IMR shows higher clinical sensitivity and specificity than those of CLIA. Moreover, the rate of false positives for smoking subjects is clearly reduced through the use of IMR. All the results demonstrate IMR is a promising alternative assay for serum CEA to diagnose CRC.

Elevated Serum Carcinoembryonic Antigen Is Associated with a Worse Survival Outcome of Patients After Liver Resection for Hepatocellular Carcinoma: a Propensity Score Matching Analysis

BACKGROUND

The relationship between serum carcinoembryonic antigen (CEA) and postoperative prognosis in hepatocellular carcinoma (HCC) has not been reported.

METHODS

Data of 5410 consecutive HCC patients who underwent hepatectomy was retrospectively reviewed. Survival curves for overall survival (OS) and tumor recurrence (TR) were depicted using the Kaplan-Meier method and compared using the log-rank test. Independent risk factors of OS and TR were analyzed with Cox hazard regression model. Besides, a one-to-one propensity score-matched (PSM) subset was performed to reduce selection bias. Subgroup analysis was done according to hepatitis B virus (HBV) infection or not.

RESULTS

Serum CEA ≥5.1 μg/L was an independent risk factor of OS and TR in the entire cohort and PSM subset (OS-hazard ratio = 1.218, 95 % confidence interval = 1.060-1.400; 1.383, 1.133-1.688, respectively; TR-1.256, 1.114-1.417; 1.258, 1.067-1.484, respectively). Subgroup analysis showed that CEA ≥5.1 μg/L was an independent risk factor of OS and TR in the HBV infection group (OS-1.234, 1.065-1.429; TR-1.231, 1.083-1.399) but not in the non-HBV infection group (OS-1.376, 0.895-2.117; TR-1.437, 0.989-2.088).

CONCLUSION

Serum CEA ≥5.1 μg/L was an independent risk factor of OS and TR of HCC patients, and patients with CEA ≥5.1 μg/L had poorer prognosis, especially for HCC patients with HBV infection.

Long-Term Follow-Up and Survivorship After Completing Systematic Surveillance in Stage I-III Colorectal Cancer: Who Is Still at Risk?

PURPOSE

In patients with a high life expectancy at the time of surgery for colorectal cancer (CRC), the long-term outcome may be influenced by factors other than their cancer. We aimed to investigate the long-term outcome and cause of death beyond a 5-year surveillance programme.

METHODS

We evaluated the overall survival (OS) and cancer-specific survival (CSS) of a population-based cohort of stage I-III CRC patients <75 years old who completed a systematic surveillance programme.

RESULTS

In total, 161 patients <75 years old, 111 (69 %) of whom were node negative (pN0), were included. The median follow-up time was 12.1 years. The OS was 54 % at 15 years and differed significantly between the pN0 and pN+ patients (65 vs. 30 %; P < 0.001); CSS (72 %) also differed between the pN0 and pN+ patients (85 vs. 44 %; P < 0.001). For the 5-year survivors (n = 119), 14 (12 %) died of CRC during additional long-term follow-up (7 each for pN0 and pN+), and 6 patients (5 %; all pN0) died of other cancers. Patients aged <65 years exhibited better long-term survival (81 %), but most of the deaths were due to CRC (10/12 deaths). Only two of the 14 cancer-related deaths involved microsatellite instable (MSI) CRC. Females exhibited better OS and CSS beyond 5 years of surveillance.

CONCLUSIONS

The long-term survival beyond 5-year survivorship for stage I-III CRC is very good. Nonetheless, cancer-related deaths are encountered in one-third of patients and occur most frequently in patients who are <65 years old at disease onset-pointing to a still persistent risk several years after surgery.

Direct and multiplex quantification of protein biomarkers in serum samples using an immuno-magnetic platform

A direct and ultrasensitive multiplex assay using an immuno-magnetic platform has been developed for the quantification of trace amounts of circulating cancer-associated antigens in serum.

A direct and ultrasensitive multiplex assay using an immuno-magnetic platform has been developed for the quantification of trace amounts of circulating cancer-associated antigens in serum. The detection is based on the specific immuno-interactions among the target antigen, detection antibody and capture antibody that is immobilized on the surface of magnetic nanoparticles. The sandwiched immuno-assembly is then labelled with turn-on fluorophores and detected with a fluorescence imaging system. To afford a high signal-to-noise ratio, three turn-on fluorophores with unique optical properties have been designed and synthesized to label the target antigens. The developed assay has achieved a remarkable LOD down to the femto-molar regime without sample pre-treatment. This versatile assay can efficiently differentiate the target antigen from a protein matrix and simultaneously quantify multiple cancer-associated antigens, for instance, alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and prostate specific antigen (PSA) using only 6 μL of serum sample in an hour. This novel system has a high applicability to serve as a universal and useful tool for early disease diagnostics.

The diagnostic accuracy of carcinoembryonic antigen to detect colorectal cancer recurrence - A systematic review

INTRODUCTION

Carcinoembryonic Antigen (CEA) has been used as a tumor marker in the follow-up of colorectal cancer for more than 40 years. Controversy exists regarding its diagnostic applicability due to a relatively low sensitivity and a questionable effect on mortality. The aim of this review was to assess the diagnostic accuracy of CEA in detecting recurrence after intended curative surgery for primary colorectal cancer.

METHODS

Systematic literature searches were performed in PubMed, EMBASE and Cochrane databases, and articles were chosen based on predefined inclusion criteria. Reference lists from included articles were manually searched for additional publications of relevance.

RESULTS

Forty-two original studies with generally representative populations and long follow-up were included. Data were reported on outcomes from 9,834 CEA tests during follow-up. Reporting on the reference standards used was not optimal. Sensitivity of CEA ranged from 17.4 % to 100 %, specificity ranged from 66.1 % to 98.4 %, positive predictive value ranged from 45.8 % to 95.2% and negative predictive value ranged from 74.5 % to 100 %.

CONCLUSION

Results point toward a sensitivity of CEA ranging between 50 % and 80 %, and a specificity and negative predictive value above 80 %. Results on positive predictive value showed low reliability. Overall, CEA did not effectively detect treatable recurrences at an early stage, and a clinically relevant effect on patient mortality remains to be proven.

Blood CEA levels for detecting recurrent colorectal cancer

BACKGROUND

Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation.

OBJECTIVES

To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice.

SEARCH METHODS

We conducted all searches to January 29 2014. We applied no language limits to the searches, and translated non-English manuscripts. We searched for relevant reviews in the MEDLINE, EMBASE, MEDION and DARE databases. We searched for primary studies (including conference abstracts) in the Cochrane Central Register of Controlled Trials (CENTRAL), in MEDLINE, EMBASE, and the Science Citation Index & Conference Proceedings Citation Index - Science. We identified ongoing studies by searching WHO ICTRP and the ASCO meeting library.

SELECTION CRITERIA

We included cross-sectional diagnostic test accuracy studies, cohort studies, and randomised controlled trials (RCTs) of post-resection colorectal cancer follow-up that compared CEA to a reference standard. We included studies only if we could extract 2 x 2 accuracy data. We excluded case-control studies, as the ratio of cases to controls is determined by the study design, making the data unsuitable for assessing test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors (BDN, IP) assessed the quality of all articles independently, discussing any disagreements. Where we could not reach consensus, a third author (BS) acted as moderator. We assessed methodological quality against QUADAS-2 criteria. We extracted binary diagnostic accuracy data from all included studies as 2 x 2 tables. We conducted a bivariate meta-analysis. We used the xtmelogit command in Stata to produce the pooled estimates of sensitivity and specificity and we also produced hierarchical summary ROC plots.

MAIN RESULTS

In the 52 included studies, sensitivity ranged from 41% to 97% and specificity from 52% to 100%. In the seven studies reporting the impact of applying a threshold of 2.5 µg/L, pooled sensitivity was 82% (95% confidence interval (CI) 78% to 86%) and pooled specificity 80% (95% CI 59% to 92%). In the 23 studies reporting the impact of applying a threshold of 5 µg/L, pooled sensitivity was 71% (95% CI 64% to 76%) and pooled specificity 88% (95% CI 84% to 92%). In the seven studies reporting the impact of applying a threshold of 10 µg/L, pooled sensitivity was 68% (95% CI 53% to 79%) and pooled specificity 97% (95% CI 90% to 99%).

AUTHORS' CONCLUSIONS

CEA is insufficiently sensitive to be used alone, even with a low threshold. It is therefore essential to augment CEA monitoring with another diagnostic modality in order to avoid missed cases. Trying to improve sensitivity by adopting a low threshold is a poor strategy because of the high numbers of false alarms generated. We therefore recommend monitoring for colorectal cancer recurrence with more than one diagnostic modality but applying the highest CEA cut-off assessed (10 µg/L).

Diagnostic value of (18)F-FDG PET/CT as first choice in the detection of recurrent colorectal cancer due to rising CEA

Background

The diagnostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) as the first imaging approach in the evaluation of rising carcinoembryonic antigen (CEA) is not clear. The objective of this study was to investigate the value of ¹⁸F-FDG PET/CT in patients with colorectal cancer (CRC) and suspected recurrence based on rising CEA.

Methods

A total of 73 patients with CRC were referred to PET/CT after radical surgery. Generally, all patients were scheduled to follow a CT-based post-surgical follow-up regimen. In the case of rising CEA, ¹⁸F-FDG PET/CT was performed in most patients with contrast-enhanced CT. The PET/CT images were independently reviewed by two readers. The presence or absence of recurrence was based on histology and/or standardized clinical follow-up.

Results

Among 35 patients who had confirmed recurrence of CRC, PET/CT demonstrated recurrence with a sensitivity of 85.7 %, a specificity of 94.7 %, a positive predictive value of 93.8 %, and a negative predictive value of 87.8 %. The SUV_max ranged from 1.3 to 19.9. The mean time since the last postoperative imaging and PET/CT was 8 months (median 4 months). CEA values at referral ranged from 1.5 to 164.0 μg/L (median 5.6 μg/L). The diagnostic properties of PET/CT were analyzed in subgroups of patients with a single rising CEA sample (30 patients, 41 %), 31 patients (43 %) with two or more consecutive increases, and 12 patients (16 %) with persistently elevated values.

Conclusions

¹⁸F-FDG PET/contrast-enhanced CT has high diagnostic accuracy in the diagnosis of recurrent CRC, even in patients in a conventional CT-based follow-up program.

Model-independent evaluation of tumor markers and a logistic-tree approach to diagnostic decision support

Sensitivity and specificity of using individual tumor markers hardly meet the clinical requirement. This challenge gave rise to many efforts, e.g., combing multiple tumor markers and employing machine learning algorithms. However, results from different studies are often inconsistent, which are partially attributed to the use of different evaluation criteria. Also, the wide use of model-dependent validation leads to high possibility of data overfitting when complex models are used for diagnosis. We propose two model-independent criteria, namely, area under the curve (AUC) and Relief to evaluate the diagnostic values of individual and multiple tumor markers, respectively. For diagnostic decision support, we propose the use of logistic-tree which combines decision tree and logistic regression. Application on a colorectal cancer dataset shows that the proposed evaluation criteria produce results that are consistent with current knowledge. Furthermore, the simple and highly interpretable logistic-tree has diagnostic performance that is competitive with other complex models.

Discovery and validation of new potential biomarkers for early detection of colon cancer

BACKGROUND

Accurate detection of characteristic proteins secreted by colon cancer tumor cells in biological fluids could serve as a biomarker for the disease. The aim of the present study was to identify and validate new serum biomarkers and demonstrate their potential usefulness for early diagnosis of colon cancer.

METHODS

The study was organized in three sequential phases: 1) biomarker discovery, 2) technical and biological validation, and 3) proof of concept to test the potential clinical use of selected biomarkers. A prioritized subset of the differentially-expressed genes between tissue types (50 colon mucosa from cancer-free individuals and 100 normal-tumor pairs from colon cancer patients) was validated and further tested in a series of serum samples from 80 colon cancer cases, 23 patients with adenoma and 77 cancer-free controls.

RESULTS

In the discovery phase, 505 unique candidate biomarkers were identified, with highly significant results and high capacity to discriminate between the different tissue types. After a subsequent prioritization, all tested genes (N = 23) were successfully validated in tissue, and one of them, COL10A1, showed relevant differences in serum protein levels between controls, patients with adenoma (p = 0.0083) and colon cancer cases (p = 3.2e-6).

CONCLUSION

We present a sequential process for the identification and further validation of biomarkers for early detection of colon cancer that identifies COL10A1 protein levels in serum as a potential diagnostic candidate to detect both adenoma lesions and tumor.

IMPACT

The use of a cheap serum test for colon cancer screening should improve its participation rates and contribute to decrease the burden of this disease.

A prospective analysis of false positive events in a National Colon Cancer Surveillance Program

Background

The survival benefits of colon cancer surveillance programs are well delineated, but less is known about the magnitude of false positive testing. The objective of this study was to estimate the false positive rate and positive predictive value of testing as part of a surveillance program based on national guidelines, and to estimate the degree of testing and resource use needed to identify a curable recurrence.

Methods

Analysis of clinically significant events leading to suspicion of cancer recurrence, false positive events, true cancer recurrences, time to confirmation of diagnosis, and resource use (radiology, blood samples, colonoscopies, consultations) among patients included in a randomised colon cancer surveillance trial.

Results

110 patients surgically treated for colon cancer were followed according to national guidelines for 1884 surveillance months. 1105 tests (503 blood samples, 278 chest x-rays, 209 liver ultrasounds, 115 colonoscopies) and 1186 health care consultations were performed. Of the 48 events leading to suspicion of cancer recurrence, 34 (71%) represented false positives. Thirty-one (65%) were initiated by new symptoms, and 17 (35%) were initiated by test results. Fourteen patients had true cancer recurrence; 7 resections of recurrent disease were performed, 4 of which were successful R0 metastasis Resections. 276 tests and 296 healthcare consultations were needed per R0 resection; the cost per R0 surgery was £ 103207. There was a 29% probability (positive predictive value) of recurrent cancer when a diagnostic work-up was initiated based on surveillance testing or patient complaints.

Conclusion

We observed a high false positive rate and low positive predictive value for significant clinical events suggestive of possible colorectal cancer relapse in the setting of a post-treatment surveillance program based on national guidelines. Providers and their patients should have an appreciation for the modest positive predictive value inherent in colorectal cancer surveillance programs in order to make informed choices, which maximize quality of life during survivorship. Better means of tailoring surveillance programs based on patient risk would likely lead to more effective and cost-effective post-treatment follow-up.

Trial registration

ClinicalTrials.gov identifier NCT00572143. Date of trial registration: 11^th of December 2007.

Colorectal cancer diagnostics: biomarkers, cell-free DNA, circulating tumor cells and defining heterogeneous populations by single-cell analysis

Reliable biomarkers are needed to guide treatment of colorectal cancer, as well as for surveillance to detect recurrence and monitor therapeutic response. In this review, the authors discuss the use of various biomarkers in addition to serum carcinoembryonic antigen, the current surveillance method for metastatic recurrence after resection. The clinical relevance of mutations including microsatellite instability, KRAS, BRAF and SMAD4 is addressed. The role of circulating tumor cells and cell-free DNA with regards to their implementation into clinical use is discussed, as well as how single-cell analysis may fit into a monitoring program. The detection and characterization of circulating tumor cells and cell-free DNA in colorectal cancer patients will not only improve the understanding of the development of metastasis, but may also supplant the use of other biomarkers.

Diagnostic Accuracy of Elevated Serum Carcinoembryonic Antigen for Recurrence in Postoperative Stage II Colorectal Cancer Patients: Comparison With Stage III

Purpose

Elevated levels of serum carcinoembryonic antigen (CEA) following a curative resection of colorectal cancer (CRC) indicate recurrence; however, the levels of CEA may be elevated above the normal limit without recurrence. The aim of this study is to analyze the diagnostic accuracy of elevated serum CEA for predicting recurrence in postoperative stage II and stage III CRC patients.

Methods

A total of 336 stage II and stage III CRC patients who underwent a curative resection between January 2005 and October 2009 were enrolled. Sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), likelihood ratios and post-test probabilities of recurrence associated with elevated CEA were analyzed and compared.

Results

The median follow-up duration was 45 months (36 to 134 months). Twenty-seven of 189 stage II patients (14.3%) and 52 of 147 stage III patients (35.4%) developed recurrence during the follow-up period. Sensitivities, specificities, PPVs, and NPVs of elevated CEA were 37.0%, 91.4%, 41.7%, and 89.7%, respectively, in stage II patients and 46.2%, 90.5%, 72.7%, and 75.4% in stage III patients. Post-test probabilities of recurrence associated with elevated CEA were 41.8% in stage II patients and 71.9% in stage III patients.

Conclusion

The predictive performance of the probability of recurrence associated with elevated serum CEA after a curative resection in stage II CRC patients is lower than that in stage III CRC patients.

Association between carcinoembryonic antigen, carbohydrate antigen 19-9 and body mass index in colorectal cancer patients

Carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) have been well recognized as tumor markers for colorectal cancer. Previous studies suggested that obesity is inversely associated with the screening of CEA and CA19-9 levels and may reduce screening sensitivity. This study was conducted to evaluate the association of body mass index (BMI) with serum CEA and CA19-9 concentration in colorectal cancer patients. A total of 300 patients were enrolled in the study, selected from 2,950 consecutive colorectal cancer patients who underwent surgical treatment between August, 1994 and December, 2005. The association of BMI with CEA concentration, total circulating CEA mass and plasma volume was assessed by determining P-values for trends. The multivariate linear regression analysis was used to adjust for clinicopathological confounding factors to analyze the main outcome measures when CEA and CA19-9 had been log-transformed. Increased BMI was linearly correlated with a higher plasma volume. Using the stepwise method, the multiple regression model including BMI categories was reconstructed as follows: log_e[CEA]=0.208+0.241[liver metastasis]+0.051 [differentiation]+0.092[TNM]; log_e[CA19-9]=0.969+0.233 [gender]+0.141[ascites]+0.09[TNM]. The mean survival time in CEA⁺/CA19-9⁻, CEA⁺/CA19-9⁺, CEA⁻/CA19-9⁻ and CEA⁻/CA19-9⁺ patients was 84.8, 58.2, 100.6 and 74.7 months, respectively. The 1-/3-year survival rates in each group was 76.0/59.8, 66.2/43.5, 96.3/87.6 and 71.7/41.0, respectively. In conclusion, the decreased concentration of CEA and CA19-9 in patients of higher BMIs may be the result of the hemodilution effect. The BMI factor should be considered during the surveillance of colorectal cancer. In addition, patients with simultaneous positive expression of CEA and CA19-9 exhibited shorter survival time.

Cost-effectiveness and quality of life in surgeon versus general practitioner-organised colon cancer surveillance: a randomised controlled trial

OBJECTIVE

To assess whether colon cancer follow-up can be organised by general practitioners (GPs) without a decline in the patient's quality of life (QoL) and increase in cost or time to cancer diagnoses, compared to hospital follow-up.

DESIGN

Randomised controlled trial.

SETTING

Northern Norway Health Authority Trust, 4 trusts, 11 hospitals and 88 local communities.

PARTICIPANTS

Patients surgically treated for colon cancer, hospital surgeons and community GPs.

INTERVENTION

24-month follow-up according to national guidelines at the community GP office. To ensure a high follow-up guideline adherence, a decision support tool for patients and GPs were used.

MAIN OUTCOME MEASURES

Primary outcomes were QoL, measured by the global health scales of the European Organisation for Research and Treatment of Cancer QoL Questionnaire (EORTC QLQ C-30) and EuroQol-5D (EQ-5D). Secondary outcomes were cost-effectiveness and time to cancer diagnoses.

RESULTS

110 patients were randomised to intervention (n=55) or control (n=55), and followed by 78 GPs (942 follow-up months) and 70 surgeons (942 follow-up months), respectively. Compared to baseline, there was a significant improvement in postoperative QoL (p=0.003), but no differences between groups were revealed (mean difference at 1, 3, 6, 9, 12, 15, 18, 21 and 24-month follow-up appointments): Global Health; Δ-2.23, p=0.20; EQ-5D index; Δ-0.10, p=0.48, EQ-5D VAS; Δ-1.1, p=0.44. There were no differences in time to recurrent cancer diagnosis (GP 35 days vs surgeon 45 days, p=0.46); 14 recurrences were detected (GP 6 vs surgeon 8) and 7 metastases surgeries performed (GP 3 vs surgeon 4). The follow-up programme initiated 1186 healthcare contacts (GP 678 vs surgeon 508), 1105 diagnostic tests (GP 592 vs surgeon 513) and 778 hospital travels (GP 250 vs surgeon 528). GP organised follow-up was associated with societal cost savings (£8233 vs £9889, p<0.001).

CONCLUSIONS

GP-organised follow-up was associated with no decline in QoL, no increase in time to recurrent cancer diagnosis and cost savings.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00572143.

Role of serum carcinoembryonic antigen in the detection of colorectal cancer before and after surgical resection

AIM: To determine whether serum levels of carcinoembryonic antigen (CEA) correlate with the presence of primary colorectal cancer (CRC), and/or recurrent CRC following radical resection.

METHODS: A total of 413 patients with CRC underwent radical surgery between January 1998 and December 2002 in our department and were enrolled in this study. The median follow-up period was 69 mo (range, 3-118 mo), and CRC recurrence was experienced by 90/413 (21.8%) patients. Serum levels of CEA were assayed preoperatively, and using a cutoff value of 5 ng/mL, patients were divided into two groups, those with normal serum CEA levels (e.g., ≤ 5 ng/mL) and those with elevated CEA levels (> 5 ng/mL).

RESULTS: The overall sensitivity of CEA for the detection of primary CRC was 37.0%. The sensitivity of CEA according to stage, was 21.4%, 38.9%, and 41.7% for stages I-III, respectively. Moreover, for stage II and stage III cases, the 5-year disease-free survival rates were reduced for patients with elevated preoperative serum CEA levels (P < 0.05). The overall sensitivity of CEA for detecting recurrent CRC was 54.4%, and sensitivity rates of 36.6%, 66.7%, and 75.0% were associated with cases of local recurrence, single metastasis, and multiple metastases, respectively. In patients with normal serum levels of CEA preoperatively, the sensitivity of CEA for detecting recurrence was reduced compared with patients having a history of elevated CEA prior to radical resection (32.6% vs 77.3%, respectively, P < 0.05).

CONCLUSION: CRC patients with normal serum CEA levels prior to resection maintained these levels during CRC recurrence, especially in cases of local recurrence vs cases of metastasis.

Adherence to national guidelines for surveillance after curative resection of nonmetastatic colon and rectum cancer: a survey among Norwegian gastrointestinal surgeons

AIM

National guidelines recommend enrollment of patients in surveillance programmes following curative resection of colorectal carcinoma (CRC) in order to detect recurrence or distant metastasis at an asymptomatic/early stage when secondary curative treatment can be offered. Little is known about surgeons' adherence to such guidelines. In this national survey we analyse adherence and attitudes to postoperative follow up among Norwegian gastrointestinal surgeons involved in the care of patients with CRC.

METHOD

We performed a nationwide survey of all hospitals performing surgery for colon and/or rectum cancer. The presence of a surveillance programme, the type of programme, adherence to national guidelines or report on any deviation thereof, location of follow up at the hospital or with a general practitioner (GPs) and the estimated annual volume of surgery were queried through mail and telephone.

RESULTS

All hospitals (n=41) performing colorectal surgery responded, of which 25 (61%) conducted postoperative follow up by surgeons in the hospital outpatient clinics, four (10%) carried out follow up with a combination of hospital outpatient visits and visits to GPs, and 12 (29%) referred surveillance to the GP alone. For total reported patient numbers, almost two-thirds (60%) received surveillance according to national recommendations through outpatient visits with the surgeon or GP, while one-third (37%) were subject to other alternative routines. A small number (2%) received informal 'ad hoc' surveillance only. More liberal use of imaging outside guideline recommendations was reported for rectal cancer patients, while colon cancer patients treated in larger hospitals were more likely to be referred for GP surveillance.

CONCLUSION

All hospitals reported having a strategy for surveillance after surgery for colon and rectal cancer, but there was considerable variance in strategy. A scientific audit of the true level of compliance, effectiveness and cost-benefit is warranted at a national level.

Role of carcinoembryonic antigen, magnetic resonance imaging, and positron emission tomography-computed tomography in the evaluation of patients with suspected local recurrence of colorectal cancer

The role of carcinoembryonic antigen (CEA), magnetic resonance imaging (MRI), and positron emission tomography (PET)-computed tomography (CT) in detection of local recurrence of colorectal cancer is evaluated in 71 patients, selected due to suspected relapse at CT follow-up. Recurrence was confirmed by histology in 18 cases and excluded in 25 cases. Sensitivity, specificity, positive and negative predictive values, and accuracy were as follows: 44.4%, 92.5%, 66.7%, 83.1%, and 80.3% for CEA; 88.9%, 73.6%, 53.3%, 95.1%, and 77.5% for MRI; and 94.4%, 73.6%, 54.8%, 97.5%, and 78.9% for PET-CT. A diagnostic protocol integrating CEA and dedicated imaging studies is to be advocated.

Accuracy of monitoring serum carcinoembryonic antigen levels in postoperative stage III colorectal cancer patients is limited to only the first postoperative year

PURPOSE

The aim of the present study was to determine the accuracy of yearly postoperative monitoring of serum tumor markers to either detect or rule out recurrence in colorectal cancer patients.

METHODS

A total of 127 colorectal cancer patients who underwent curative surgery were enrolled. The serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels were assayed, and radiological examinations were performed routinely for 5 years after surgery or until recurrence was detected. Yearly recurrence rates (number of recurrences/number of patients assessed in a given year), sensitivities, specificities, and likelihood ratios were calculated. Post-test probabilities were calculated from these values.

RESULTS

Recurrences tended to show almost the same frequencies in the first and second year after surgery (20 of 127 patients and 18 of 107 patients, respectively). However, the post-test probability of recurrence in patients with positive and negative serum CEA levels was significantly lower in the second year than in the first year (test positive: 40.0% and 76.0%; test negative: 9.3% and 0.5%, respectively).

CONCLUSIONS

Measuring CEA can help to identify patients likely to demonstrate recurrence with high accuracy only within the first year after surgery. Another examination, such as imaging, is therefore necessary for monitoring patients at 2 or more years after surgery.

Biomarkers and microsatellite instability analysis of curettings can predict the behavior of FIGO stage I endometrial endometrioid adenocarcinoma

The prognostic value of molecular biomarkers, microsatellite instability, DNA ploidy and morphometric mean shortest nuclear axis in endometrial cancer is conflicting, possibly due to the fact that different studies have used mixtures of histotypes, FIGO stages and different non-standardized non-automated methods. We have evaluated the prognostic value of classical prognostic factors, molecular biomarkers, microsatellite instability, DNA ploidy and morphometric mean shortest nuclear axis in a population-based cohort of FIGO stage I endometrial endometrioid adenocarcinomas. Curettings of 224 FIGO stage I endometrial endometrioid adenocarcinoma patients were reviewed. Clinical information, including follow-up, was obtained from the patients' charts. Microsatellite instability and morphometric mean shortest nuclear axis were obtained in whole tissue sections and molecular biomarkers using tissue microarrays. DNA ploidy was analyzed by image cytometry. Univariate (Kaplan-Meier method) and multivariate (Cox model) survival analysis was performed. With median follow-up of 66 months (1-209), 14 (6%) patients developed metastases. Age, microsatellite instability, molecular biomarkers (p16, p21, p27, p53 and survivin) and morphometric mean shortest nuclear axis had prognostic value. With multivariate analysis, combined survivin, p21 and microsatellite instability overshadowed all other variables. Patients in which any of these features had favorable values had an excellent prognosis, in contrast to those with either high survivin or low p21 (97 vs 78% survival, P<0.0001, hazard ratio=7.8). Combined high survivin and low p21 values and microsatellite instability high identified a small subgroup with an especially poor prognosis (survival rate 57%, P=0.01, hazard ratio=5.6). We conclude that low p21 and high survivin expression are poor prognosis indicators in FIGO stage I endometrial endometrioid adenocarcinoma, especially when high microsatellite instability occurs.

Prognostic role of carcinoembryonic antigen is influenced by microsatellite instability genotype and stage in locally advanced colorectal cancers

BACKGROUND

Carcinoembryonic antigen (CEA) is the most frequently used marker for colorectal cancer (CRC). Influence of genetic instability on tumor marker expression is not known. The aim of this study was to investigate microsatellite instability (MSI) of CEA serum levels in locally advanced CRC.

METHODS

The observational cohort consisted of stage II-III CRC patients (n = 131) 75 years old or youngerwho underwent surgery with curative intent. CEA serum levels were measured before (preCEA) and immediately after surgery (postCEA). DNA from the extracted tumors was investigated for MSI. Survival was analyzed in univariate and multivariate analyses.

RESULTS

The median preCEA was 3 U/ml (IQR = 1-3, range = 1-136 U/ml). Stage III cancers with MSI had an elevated preCEA more often than those without MSI (25% vs. 0%; p = 0.026). A preCEA >10 U/ml was significantly associated with elevated postCEA (CEA >1 U/ml; odds ratio [OR] = 5.4, 95% CI = 2.1-14.2; p < 0.001). Survival wasnot significantly different between those with postCEA <10 U/ml vs. postCEA ≥ 10 U/ml or when stratified by MSI status. A cutoff of postCEA ≤ 1 U/ml conferred significantly improved survival compared to higher CEA levels. Stratified for MSI status, this difference was significant for microsatellite stable (MSS) cancers only (p = 0.021). In multivariate analysis, postCEA >1 U/ml (hazard ratio [HR] = 3.5, 95% CI = 1.7-7.3, p = 0.001) and stage III (HR = 6.7, 95% CI = 3.0-14.9; p < 0.001) were predictors of decreased survival.

CONCLUSIONS

Preoperative CEA levels were significantly higher in stage III cancers with the MSI genotype, and high preoperative CEA was associated with increased postoperative CEA. Absent postoperative CEA in serum conferred improved long-term survival.

High frequency microsatellite instability has a prognostic value in endometrial endometrioid adenocarcinoma, but only in FIGO stage 1 cases

OBJECTIVES

To analyze the prognostic value of microsatellite instability (MSI) in a population-based study of FIGO stage 1-4 endometrial endometrioid adenocarcinomas.

STUDY DESIGN

Survival analysis in 273 patients of MSI status and clinico-pathologic features. Using a highly sensitive pentaplex polymerase chain reaction to establish MSI status, cases were divided into microsatellite stable (MSS), MSI-low (MSI-L, 1 marker positive) and MSI-high (MSI-H, 2-5 markers positive).

RESULTS

After 61 months median follow-up (1-209), 34 (12.5%) of the patients developed metastases but only 6.4% of the FIGO-1. MSI (especially as MSI-H versus MSS/MSI-Lcombined) was prognostic in FIGO-1 but not in FIGO2-4. The 5 and 10 year recurrence-free survival rates were 98% and 95% in the MSS/MSI-L versus 85% and 73% in the MSI-H patients (P = 0.005).

CONCLUSIONS

MSI-H status assessed by pentaplex polymerase chain reaction is an indicator of poor prognosis in FIGO 1, but not in FIGO 2-4 endometrial endometrioid adenocarcinomas.

Molecular biomarkers in endometrial hyperplasias predict cancer progression

OBJECTIVE

The purpose of this study was to assess the value of the 2003 World Health Organization (WHO) and endometrial intraepithelial neoplasia (EIN) classifications, D-score, and molecular biomarkers in endometrial hyperplasia (EH) for cancer progression.

STUDY DESIGN

We conducted a review of 307 endometrial hyperplasias for WHO and EIN classifications and an analysis of biomarkers, D-score, and cancer progression-free survival.

RESULTS

The WHO, EIN, D-score, and many biomarkers were prognostic; 7.2% of the samples progressed to cancer. The WHO and EIN classifications correlated weakly with CK5/6 and p16. The D-score was strongest prognostically. When >1, it had the lowest false-negative progression rate of all features analyzed. COX2 negativity was the only other independent multivariate cancer progression predictor in endometrial hyperplasia, but only in cases with D-score <1. Eight of 13 cases (61%), with a combined D-score of <1 and negative COX2 progressed, which contrasted with 3 of 139 of all other cases (2.8%) (P < .0001; hazard ratio, 53.0). The biomarkers did not strengthen the prognostic value of the WHO or EIN classification.

CONCLUSION

Combined D-score <1 and COX2 negativity strongly predict cancer progression in endometrial hyperplasias.

Diagnostic accuracy and receiver-operating characteristics curve analysis in surgical research and decision making

In surgical research, the ability to correctly classify one type of condition or specific outcome from another is of great importance for variables influencing clinical decision making. Receiver-operating characteristic (ROC) curve analysis is a useful tool in assessing the diagnostic accuracy of any variable with a continuous spectrum of results. In order to rule a disease state in or out with a given test, the test results are usually binary, with arbitrarily chosen cut-offs for defining disease versus health, or for grading of disease severity. In the postgenomic era, the translation from bench-to-bedside of biomarkers in various tissues and body fluids requires appropriate tools for analysis. In contrast to predetermining a cut-off value to define disease, the advantages of applying ROC analysis include the ability to test diagnostic accuracy across the entire range of variable scores and test outcomes. In addition, ROC analysis can easily examine visual and statistical comparisons across tests or scores. ROC is also favored because it is thought to be independent from the prevalence of the condition under investigation. ROC analysis is used in various surgical settings and across disciplines, including cancer research, biomarker assessment, imaging evaluation, and assessment of risk scores.With appropriate use, ROC curves may help identify the most appropriate cutoff value for clinical and surgical decision making and avoid confounding effects seen with subjective ratings. ROC curve results should always be put in perspective, because a good classifier does not guarantee the expected clinical outcome. In this review, we discuss the fundamental roles, suggested presentation, potential biases, and interpretation of ROC analysis in surgical research.

An intelligent decision support algorithm for diagnosis of colorectal cancer through serum tumor markers

Nowadays, a wide range of serum tumor markers can be applied in the diagnosis of colorectal cancer. There exists a wide variability in the type and number of routinely used markers so that, sometimes, patients may receive redundant or insufficient checks. Furthermore, the traditional single cutoff point also hinders the efficient utilization of the continuous check value of a tumor marker. In order to improve the diagnostic accuracy (DA) and decrease the cost, it is necessary to optimize the check combinations and exploit the check values fully. To this end, focusing on colorectal cancer (CRC), an artificial intelligent algorithm entitled DS-STM (diagnosis strategy of serum tumor makers) is developed in this paper. DS-STM can provide decision support for physicians on the usage of different tumor markers and diagnosis of colorectal cancer (CRC). The study demonstrates that, instead of five or more tumor markers, two markers are already enough for diagnosis for most CRC patients. The experimental study shows, compared to the traditional serial test, DS-STM can improve DA from 67.53% to 73.87% for the same validation dataset. In addition, a significant cost reduction can be achieved with the new developed diagnosis strategy.

Endoscopic surveillance after curative surgery for sporadic colorectal cancer: patient-tailored, tumor-targeted or biology-driven?

OBJECTIVE

Endoscopy has been endorsed and introduced in most surveillance programs following curative surgery for colorectal cancer (CRC), yet little data are available to support its use in terms of patient selection, efficacy and frequency of surveillance.

MATERIAL AND METHODS

A literature search in the English language using the PubMed/Medline database for the MeSH terms "colorectal cancer", "surveillance", and "endoscopy", with focus on sporadic CRC, excluding CRC developed on a hereditary or inflammatory bowel disease background. Focus on results from the past 5 years was applied.

RESULTS

Recent systematic reviews, meta-analyses, randomized trials and prospective studies made the backbone of the article, supported by population-based findings and recent reports on tumor biology. Hard evidence to support a survival benefit from endoscopy alone is lacking. Definitions of "synchronous", "interval", and "metachronous" cancers are not uniform and hampers comparison of studies. The number of metachronous cancers (usually 2-4%) that develop after curative CRC surgery is small, and better patient-tailored surveillance could improve the diagnostic yield. Compliance with endoscopy is low compared to other modalities. Age and socio-demographic factors influence on the surveillance coverage and need to be addressed in any given program. The majority of local recurrences occur within the first 3 years after surgery independent of stage, and microsatellite instable (MSI) tumors appear to be at higher risk.

CONCLUSIONS

Endoscopy in surveillance after curative surgery for CRC is a resource demanding procedure. A tailored approach according to factors associated with an increased risk for metachronous cancer/local recurrence would increase efficiency.

Lymph node harvest in colon cancer: influence of microsatellite instability and proximal tumor location

BACKGROUND

At least 12 harvested lymph nodes are recommended for proper staging of colon cancer. The effect of tumor-related factors associated with lymph node harvest is not well understood as data are lacking. We investigated tumor-related factors in relation to the number of lymph nodes harvested.

METHODS

Patient and tumor characteristics were investigated in relation to harvested lymph nodes (LN >or= 12), number of metastatic nodes, LN ratio (LNR), and prognosis with univariate and multivariate analyses.

RESULTS

An LN harvest >or=12 nodes was achieved in 36% of the patients. Having <12 nodes harvested was not associated with increased risk for locoregional recurrence, distant metastasis, or decreased survival. Tumor size >5 cm, microsatellite instability (MSI), and proximal tumor location predicted a harvest of LN >or= 12. The highest rate (54%) of LN >or= 12 was found for MSI cancers [odds ratio (OR) 2.9, 95% confidence interval (CI) 1.3-6.5; P = 0.011]. Multivariate analysis identified a proximal location as an independent factor of LN >or= 12 (adjusted OR 3.5, 95% CI 1.5-8.2; P = 0.003), with MSI an independent factor in stage II to III colon cancer (adjusted OR 2.6, 95% CI 1.1-6.0; P = 0.026). To determine the best prognosticator, LNR was the only significant factor in the multivariate analysis (Cox proportional hazards) with a hazard ratio (HR) of 2.9 (95% CI 1.1-7.8; P = 0.038) for LNR 0.01-0.17 and an HR of 5.8 (95% CI 2.5-13.1; P < 0.001).

CONCLUSIONS

Proximal tumor location and microsatellite instability are associated with a higher number of lymph nodes harvested, pointing to possible underlying genetic and immunologic mechanisms. The LNR is an independent prognostic variable for colon cancer.

Influence of obesity on the serum carcinoembryonic antigen value in patients with colorectal cancer

BACKGROUND

Prior studies suggest that obesity is inversely associated with tumor marker concentration and may reduce diagnostic precision. This study was undertaken to evaluate the association between body mass index (BMI) and serum carcinoembryonic antigen (CEA) concentrations in colorectal cancer patients.

METHODS

We analyzed the association between BMI and CEA concentration in a group of 2,845 patients who underwent surgical treatment for colorectal adenocarcinoma from 1995 to 2009. Multivariate linear regression analysis was applied to adjust for clinicopathologic confounding factors to analyze main outcome measures. The association of BMI with plasma volume, CEA concentration, and total circulating CEA mass was assessed by determining P values for trends. We also developed a regression formula to calculate the effect of obesity on the serum CEA levels.

RESULTS

Increased BMI was linearly correlated with higher plasma volume (P < 0.001 for trend) and lower adjusted CEA concentrations after controlling for potentially confounding factors (P ≤ 0.005 for trend in stage II and III tumors). Our theoretical model suggests that a CEA value of 7.0 ng/mL in patients of normal weight corresponds to 6.1 ng/mL in obese patients.

CONCLUSIONS

The hemodilution effect from increased plasma volume may account for the decreased CEA concentrations observed in patients with higher BMI.

IMPACT

Obesity might be one of the factors that affect CEA value, leading to loss of sensitivity and diagnostic accuracy in the CEA test. The BMI status of patients should be taken into account during assessment of serum CEA during the surveillance of colorectal cancer.

Does serum carcinoembryonic antigen elevation in patients with postoperative stage II colorectal cancer indicate recurrence? Comparison with stage III

BACKGROUND AND OBJECTIVES

The aim of this study was to determine the accuracy of postoperative monitoring of serum carcinoembryonic antigen (CEA) to detect or rule out recurrence in patients with stage II colorectal cancer (CRC) by comparing results with stage III.

METHODS

A total of 303 patients with CRC who underwent curative surgery were enrolled. Serum CEA was assayed, and radiological examination was performed routinely for 5 years after surgery. Yearly recurrence rates, sensitivities, specificities, likelihood ratios, and posttest probabilities were calculated.

RESULTS

Sensitivity and specificity of CEA monitoring in stage II patients are almost same as those in stage III. Whereas recurrences occurred early in stage III, they occurred almost as frequently in both early and late stage II. The obtained posttest probability of recurrence in stage II patients with CEA elevation was significantly lower (only 30% or less) than those in stage III (approximately 80%).

CONCLUSION

Elevation of CEA in patients with stage II CRC does not represent recurrence with high probability. One of the reasons for the unreliability of CEA monitoring was its high false-positive rate. Another tumor marker with a lower false-positive rate is necessary to follow-up stage II CRC patients.

Lead time of carcinoembryonic antigen elevation in the postoperative follow-up of colorectal cancer did not affect the survival rate after recurrence

BACKGROUND AND AIMS

The role of carcinoembryonic antigen (CEA) in the early detection of recurrence during the postoperative follow-up of colorectal cancer remains unclear. We hypothesize that the tumor with longer lead time of CEA elevation to the definite recurrence may have a better prognosis because of its slower growth rate and closer observation.

MATERIALS AND METHODS

From 1995 to 2003, 4,841 consecutive patients who received curative resection of localized colorectal adenocarcinoma were enrolled from a prospective database. The patients with persisting CEA elevation after operation had been already excluded. Postoperative follow-up, including physical examination, imaging, and CEA test, were performed according to a surveillance program. A CEA >/=5 ng/mL was defined as elevated. The definition of the CEA lead time was the period between CEA elevation and detection of recurrence. All statistical analyses were performed by SPSS package for Windows (Microsoft, Redmond, WA, USA).

RESULTS

The postoperative median follow-up time for the 4,841 patients was 68 months. A total of 999 patients (20.6%) had CEA elevation and recurrence. Among these patients, recurrence was confirmed in 727 patients (72.8%)before, at the same time, or within 3 months of CEA elevation and thus had a short lead time of CEA elevation (SLT group). In 272 patients (27.2%), recurrence was confirmed after more than 3 months of CEA elevation and thus had a longer lead time of CEA elevation (LLT group). The recurrence pattern showed similarities in these two groups. A total of 193 patients (193/999, 19.3%) received a second radical operation, and 806 patients (80.7%) were inoperable. The re-resection rate between the SLT group (146 patients, 20.1%) and the LLT group (47 patients, 17.3%) was not significantly different. The overall survival rate after recurrence showed no difference between these two groups (P = 0.123).

CONCLUSION

Most cases of recurrence were detected at nearly the same time when the CEA level was elevated. Therefore, a more sensitive test is needed for early detection. The relationship between the lead time of CEA and the clinical outcome was not statistically significant. A more aggressive approach to the patient who has CEA elevation and is highly suspect of recurrence may be needed.

Clinical significance of CEA and CA19-9 in postoperative follow-up of colorectal cancer

BACKGROUND

We evaluated the efficiency of CEA and CA19-9 as tools for diagnosing recurrence in the postoperative surveillance of colorectal cancer.

MATERIALS AND METHODS

A total of 227 patients who underwent curative resection for colorectal cancer between 1999 and 2003 at our hospital received complete follow-up according to the schedule determined prospectively. Using receiver operating characteristic (ROC) analysis, performance of postoperative values of CEA or CA19-9 for detecting recurrence was assessed.

RESULTS

The sensitivity (1.000) and specificity (0.978) of the postoperative values of CEA in the high preoperative CEA group were very high. Even in the normal preoperative CEA group, the area under the curve (AUC) of the ROC curve of CEA (0.740, 95% confidence interval [95% CI], 0.628-0.852) was significantly larger than 0.5 (P < 0.001). The postoperative values of CA19-9 showed high sensitivity (0.833) and specificity (0.900) in the high preoperative CA19-9 group, while the AUC of the ROC curve of the normal preoperative group was as small as 0.510 (95% CI, 0.376-0.644). In the high preoperative CA19-9 group, however, there was no significant difference between the AUC of CA19-9 (0.904, 95% CI, 0.786-1.000) and that of CEA (0.869, 95% CI, 0.744-0.994) (P = 0.334).

CONCLUSIONS

The measurement of CEA is an efficient way to detect recurrence. The efficiency of measuring CA19-9 for the purpose of detecting recurrence is low, especially in patients with a normal level of preoperative CA19-9. Even in patients with a high preoperative level of CA19-9, CEA might be able to fill the role of CA19-9.

Serum p53 antibody as tumor marker for follow-up of colorectal cancer after curative resection

BACKGROUND

No large-scale studies have examined the use of serial measurements of serum p53 antibodies (s-p53Abs) combined with carcinoembryonic antigen (CEA) measurements during the follow-up of colorectal cancer (CRC) patients after curative resection.

METHODS

A highly specific enzyme-linked immunosorbent assay was used to analyze s-p53Abs levels in 305 CRC patients before and after curative resection at a single institution. Agreement between recurrence and serial s-p53Ab and CEA measurements was evaluated by diagnostic accuracy odds ratio (DOR), kappa, and area under receiver operating characteristic curve (AUC).

RESULTS

Among 305 patients, 76 (25%) patients had disease recurrence during follow-up. None of the 168 s-p53Ab seronegative patients (s-p53Ab < 10 U/microL) without recurrence had an abnormal s-p53Ab test during follow-up. Among the remaining low-level (10 U/microL <or= s-p53Ab <or= 76 U/microL, n = 103) and high-level (s-p53Ab titer > 76 U/microL, n = 34) seropositive patients, recurrence defined by s-p53Ab tests resulted in a DOR of 4.3 and infinity, a kappa of 0.35 and 1.00, and an AUC of 0.633 [95% confidence interval (CI), 0.495 to 0.772; P = 0.047], and 1.0 (95% CI, 1.000 to 1.000; P < 0.0001), respectively. Recurrence defined by CEA tests had an AUC of 0.781 (95% CI, 0.654 to 0.909) for low-level and 0.796 (95% CI, 0.611 to 0.982) for high-level seropositive patients.

CONCLUSIONS

Agreement between clinical recurrence and serial s-p53Ab test was dependent upon preoperative s-p53Ab level. Serial s-p53Ab testing outperformed CEA testing when predicting clinical recurrence in colorectal cancer patients with an abnormal preoperative s-p53Ab level.

The prognostic value of molecular biomarkers in tissue removed by curettage from FIGO stage 1 and 2 endometrioid type endometrial cancer

OBJECTIVE

To analyze the prognostic value of molecular biomarkers in curettages of endometrioid endometrial cancer pathologic FIGO stages 1 and 2.

STUDY DESIGN

Population-based survival analysis in 258 patients of classical prognostic features and molecular biomarkers of cell cycle regulation, (anti)apoptosis, proliferation, squamous differentiation, and PTEN/Akt pathway.

RESULTS

With 74 months median follow-up (range, 1-209), 24 (9.3%) patients had metastases develop. Pathologic FIGO stage 2B (6% of all cases) and age > 68 years had independent multivariate prognostic value. Many molecular biomarkers were prognostic, particularly cell-cycle regulators p16, p21, p27, p53, p63, and the antiapoptosis marker survivin (which mostly stains mitoses). The strong prognostic value of a multivariate model with survivin, p21, and p53 overshadowed all other prognosticators in pathologic FIGO 1 and 2A.

CONCLUSION

In pathologic FIGO stage 1 and 2A endometrioid endometrial cancer curettages, combined biomarkers survivin, p21, and p53 expression patterns are prognostically stronger than classical feature combinations.

Surgical treatment for rectal cancer: An international perspective on what the medical gastroenterologist needs to know

Rectal cancer accounts for one third of all colorectal cancers. The age adjusted death rates from colorectal cancer have declined over recent decades due to a combination of colorectal cancer screening, improved diagnostic tests, improved standardized surgical technique, improved medical support, neoadjuvant chemotherapies and radiation treatment or combinations of these. Because of complex treatment algorithms, use of multidisciplinary teams in the management of rectal cancer patients has also been popularized. Medical gastroenterologists performing colonoscopies are frequently the first health care provider to raise the suspicion of a rectal cancer. Although the diagnosis depends on histological confirmation, the endoscopic presentation is almost diagnostic in many cases. In order to meet the patient’s immediate needs for information, it is important that the endoscopist has knowledge about the investigations and treatment options that will be required for their patient. The aim of this paper is to describe the modern preoperative investigations and operative procedures commonly offered to rectal cancer patients taking into account perspectives of three colorectal surgeons, practicing in the USA, Europe and Asia.

Metachronous cancer development in patients with sporadic colorectal adenomas-multivariate risk model with independent and combined value of hTERT and survivin

BACKGROUND AND AIMS

Accurate, long-term risk predictors for colorectal cancer development in patients with sporadic adenomas are lacking. We sought to validate biomarkers predictive of metachronous colorectal cancer (mCRC) in patients with sporadic colorectal adenomas, using 374 consecutive patients from a large defined population.

MATERIALS AND METHODS

Risk evaluation was performed for patient and adenoma risk factors (morphometric longest nuclear axis and immunohistochemical markers survivin, human telomerase reverse transcriptase (hTERT), beta-catenin, p16INK4a, p21CIP1, and cyclin D1). Diagnostic accuracy was assessed by receiver-operating characteristics curve analysis, and uni- and multivariate survival analysis was performed.

RESULTS/FINDINGS

Of the 374 patients, 26 (7%) developed mCRC with a median of 5.6 years (range 2-19) from index adenoma. Independent risk factors included age greater than or equal to 60 years, proximal location, multiplicity (greater than or equal to three adenomas), and high-grade neoplasia, with high-grade intraepithelial neoplasia and proximal location as the strongest on multivariate analysis (hazard ratio [HR] of 4.1 and 5.2, respectively; both p< 0.05). The molecular markers hTERT (HR 11.3, 95% confidence interval [CI] 3.9-33.1; p < 0.001) and survivin (HR 7.0, 95% CI 2.4-20.5; p < 0.001) were independent predictors for mCRC, and proximal location (4 of 16 = 25% with mCRC) was the only clinical one. The value of hTERT and survivin were retained in the validation set. Survivin and hTERT together yielded high mCRC risk when both were positive (15 of 51 = 29%; HR 14.3, 5.6-36.5), modest with one positive (survivin 4 of 90 = 4.4%; hTERT 4 of 60 = 6.7%), and no risk with both negative (0 of 144 = 0%).

INTERPRETATION/CONCLUSION

hTERT and survivin are the best risk predictors for long-term, mCRC development in patients with sporadic colorectal adenomas.