Prognostic effect of perioperative change of serum carcinoembryonic antigen level: a useful tool for detection of systemic recurrence in rectal cancer

Carcinoembryonic antigen level of draining venous blood as a predictor of recurrence in colorectal cancer patient

PURPOSE

We designed this study to evaluate the efficacy of carcinoembryonic antigen in draining venous blood (vCEA) as a predictor of recurrence.

METHODS

Draining venous and supplying arterial bloods were collected separately during the operation of 82 colorectal cancer patients without distant metastasis from September 2004 to December 2006. Carcinoembryonic antigen was measured and assessed for the efficacy as a prognostic factor of recurrence using receiver operating characteristic (ROC) and Kaplan-Meier curves.

RESULTS

vCEA is a statistically significant factor that predicts recurrence (P = 0.032) and the optimal cut-off value for vCEA from ROC curve is 8.0 ng/mL. The recurrence-free survival between patients with vCEA levels >8 ng/mL and ≤8 ng/mL significantly differed (P < 0.001). The significance of vCEA as a predictor of recurrence gets higher when limited to patients without lymph node metastasis. The proper cut-off value for vCEA is 4.0 ng/mL if confined to patients without lymph node metastasis. The recurrence-free survival between the patients of vCEA levels >4 ng/mL and ≤4 ng/mL significantly differed (P < 0.001). Multivariate analysis revealed vCEA is an independent prognostic factor in patients without lymph node metastasis.

CONCLUSION

vCEA is an independent prognostic factor of recurrence in colorectal cancer patients especially in patients without lymph node metastases.

No correlation between pretreatment serum CEA levels and tumor volume in locally advanced rectal cancer patients

BACKGROUND

Although serum carcinoembryonic antigen (CEA) levels reflect tumor volume in rectal cancer patients intrapersonally, it is unclear interpersonally. We determined the correlation between pretreatment serum CEA levels and tumor volume.

METHODS

A total of 489 patients with locally advanced primary rectal cancer who underwent preoperative chemoradiotherapy followed by surgery between October 2001 and April 2007 were retrospectively evaluated. CEA levels were measured by chemiluminescent microparticle immunoassay, and magnetic resonance (MR) volumetry was performed using MR data. The correlation between CEA levels and tumor volume was assessed using linear regression analysis and one-way analysis of variance. The prognostic values of CEA levels and tumor volume for survival were evaluated.

RESULTS

There was no significant correlation between CEA levels and tumor volume. The five-year overall survival and disease-free survival were 89.0%, 80.6% and 82.9%, and 72.0%, 70.0% and 60.3% in patients with CEA levels of ≤3 ng/ml, >3-10 ng/ml, and >10 ng/ml, respectively. Tumor volume had no prognostic value for either overall survival or disease-free survival

CONCLUSIONS

Pretreatment serum CEA levels were not correlated with tumor volume. While there was no correlation between tumor volume and survival, there was a positive correlation between CEA levels and survival.

Early postoperative CEA level is a better prognostic indicator than is preoperative CEA level in predicting prognosis of patients with curable colorectal cancer

PURPOSE

Carcinoembryonic antigen (CEA) measurements performed preoperatively and during the early postoperative period were examined prospectively to assess their prognostic value for colorectal cancer (CRC) patients receiving curative surgery.

METHODS

Between 2000 and 2004, 1,361 patients with CRC who underwent curative surgery at the Taipei Veterans General Hospital were enrolled prospectively. CEA was measured prior to surgery and during the third or fourth postoperative week. The endpoint was length of postoperative disease-free survival, and prognostic importance was determined using the log-rank test and Cox regression hazard model.

RESULTS

Six hundred (44.1%) CRC patients had high CEA concentrations preoperatively, and 188 (13.8%) patients retained high values postoperatively. Within the median follow-up period of 61 (6-108) months, CRC recurred in 313 patients. By univariate analysis TNM staging, tumor differentiation, lymphovascular invasion, preoperative CEA concentration, and postoperative CEA concentration affected the outcome. By multivariate analysis, the prognostic importance of postoperative CEA was retained (95% CI, 1.73-3.01; HR = 2.28) but that of preoperative CEA was lost (95% CI, 0.82-1.33; HR = 1.05). CRC recurred earlier in patients with high postoperative CEA concentrations; metastasis to the liver was common (72.3%) among patients in this group.

CONCLUSIONS

Early postoperative CEA concentration is an independent prognostic factor for CRC. Patients with high postoperative CEA values should receive aggressive follow-up examinations for early relapse of CRC, with special attention paid to recurrence at the liver.

Prognostic factors in patients with colorectal cancer at Hospital Universiti Sains Malaysia

OBJECTIVE

To determine the 5-year survival rate and prognostic factors for survival in patients with colorectal cancer treated at the Surgical Unit, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia.

METHODS

We retrospectively reviewed the records of 115 patients treated in HUSM from 1996 to 2005. Data of variables considered as prognostic factors were obtained from the records. Simple and multiple Cox proportional hazard regression using the stepwise method were used to model the prognostic factors for survival.

RESULTS

We found that the significant prognostic factors were liver metastases [adjusted hazard ratio (HR): 3.75; 95% confidence interval (CI): 1.95-7.22], Dukes C stage (adjusted HR: 4.65; 95% CI: 2.37-9.11), Dukes D stage (adjusted HR: 6.71; 95% CI: 2.92-15.48) and non-surgical treatment (adjusted HR: 3.75; 95% CI: 1.26-11.21).

CONCLUSION

Colorectal patients treated at HUSM with Dukes C staging, presence of liver metastases and received treatment with both chemotherapy and radiotherapy are at the greatest risk of death from colorectal cancer.

Clinical significance of pre- to post-chemoradiotherapy s-CEA reduction ratio in rectal cancer patients treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the clinical significance of a reduction in serum carcinoembryonic antigen (s-CEA) concentration ratio from before to after preoperative chemoradiotherapy (CRT) in terms of recurrence and prognostic factors in rectal cancer patients.

METHODS

We retrospectively evaluated 333 rectal cancer patients who received preoperative CRT followed by surgery with curative intent between January 2000 and December 2006. Patients were divided into three groups: those with pre-CRT s-CEA≤6 ng/mL (group 1), those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA≥70% lower than pre-CRT s-CEA (group 2), and those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA<70% lower or higher than pre-CRT s-CEA (group 3).

RESULTS

The 5-year disease-free survival rate was similar in group 1 (76.0%) and group 2 (66.0%), but significantly lower in group 3 (39.5%) (p<0.001). Multivariate analysis showed that CEA group 3, ypT stage, ypN stage, and type of surgery were independent prognostic factors for disease-free survival.

CONCLUSIONS

The reduction ratio of pre- to post-CRT s-CEA concentration may be an independent prognostic factor for disease-free survival following preoperative CRT and surgery in rectal cancer patients with initial s-CEA>6 ng/mL.

The role of carcinoembryonic antigen after neoadjuvant chemoradiotherapy in patients with rectal cancer

PURPOSE

The purpose of this study was to evaluate the role of CEA after neoadjuvant chemoradiotherapy in patients with rectal cancer.

METHODS

This study involved 109 patients with rectal cancer who were treated with preoperative chemoradiotherapy and curative resection. Preoperative serum CEA levels were measured twice, before chemoradiotherapy administration and 4 weeks after chemoradiotherapy. Surgery was performed 6 to 9 weeks after neoadjuvant chemoradiotherapy.

RESULTS

The 3-year disease-free survival rate was 85.0%. On univariate analysis, prechemoradiotherapy CEA level, postchemoradiotherapy CEA level, tumor regression grade, ypT, ypN, circumferential resection margin, lymphatic invasion, venous invasion, and perineural invasion were associated with disease-free survival. Based on univariate analysis (group 1: prechemoradiotherapy CEA ≤ 3.5; group 2: prechemoradiotherapy CEA > 3.5, postchemoradiotherapy CEA ≤ 2.7; group 3: prechemoradiotherapy CEA >3.5, postchemoradiotherapy CEA > 2.7), we categorized patients into 3 groups according to their pre- and postchemoradiotherapy CEA levels (ng/mL). The 3-year disease-free survival rate was significantly better in groups 1 and 2 (94.7% and 88.0%) than in group 3 (52.6%, P < .001). On multivariate analysis, tumor regression grade (P = .036), ypN (P = .036), and CEA groups (P = .022) were identified as independent prognostic factors for disease-free survival. Furthermore, postchemoradiotherapy CEA ≤ 2.7 ng/mL was an independent predictor of good tumor regression (P = .001), ypT0 to 2 (P = .002), and ypN0 (P = .001).

CONCLUSIONS

Combined pre- and postchemoradiotherapy CEA levels could be useful as a prognostic factor for disease-free survival in patients with rectal cancer who undergo treatment with neoadjuvant chemoradiotherapy and curative resection. Postchemoradiotherapy CEA may be helpful in a selection of patients who want more conservative surgery after chemoradiotherapy.

Complete clinical response after neoadjuvant chemoradiation for distal rectal cancer

Multimodality treatment of rectal cancer, with the combination of radiation therapy, chemotherapy, and surgery has become the preferred approach to locally advanced rectal cancer. The use of neoadjuvant chemoradiation therapy (CRT) has resulted in reduced toxicity rates, significant tumor downsizing and downstaging, better chance of sphincter preservation, and improved functional results. A proportion of patients treated with neoadjuvant CRT may ultimately develop complete clinical response. Management of these patients with complete clinical response remains controversial and approaches including radical resection, transanal local excision, and observation alone without immediate surgery have been proposed. The use of strict selection criteria of patients after neoadjuvant CRT has resulted in excellent long-term results with no oncological compromise after observation alone in patients with complete clinical response. Recurrences are detectable by clinical assessment and frequently amenable to salvage procedures.

Prognostic significance of response to preoperative radiotherapy, lymph node metastasis, and CEA level in patients undergoing total mesorectal excision of rectal cancer

PURPOSE

The aim of this study was to investigate the prognostic significance of the response of primary rectal lesions to preoperative radiotherapy, pathological nodal status, and carcinoembryonic antigen (CEA) levels before and after radiotherapy in rectal cancer patients treated with a total mesorectal excision.

METHODS

We investigated the prognostic significance of the clinical and pathological factors in 97 patients treated with preoperative radiotherapy (50-50.4 Gy over 5-6 weeks) followed by curative resections.

RESULTS

A high CEA level (>5 ng/mL) after radiotherapy (hazard ratio, 2.849; 95% confidence interval, 1.061-7.651; p = 0.0377) and pathological lymph node metastasis (hazard ratio, 0.350; 95% confidence interval, 0.154-0.797; p = 0.0124) were independently associated with postoperative recurrence. Although the CEA level before radiotherapy was associated with disease-free survival in a univariate analysis, it lost its statistical significance in a multivariate analysis. The response of the primary rectal lesions, evaluated pathologically by T stage and the degree of regression, was not associated with disease-free survival. In patients without lymph node metastasis, the 5-year disease-free survival of those with a high CEA level after radiotherapy was significantly worse than those with low CEA after radiotherapy (61.6% vs. 89.0%, respectively, p = 0.0234).

CONCLUSIONS

Pathological lymph node metastasis and a high CEA level after radiotherapy were independent predictors of a poor outcome in rectal cancer patients treated with preoperative radiotherapy. The CEA level after radiotherapy was capable of discriminating patients with a high risk of recurrence among pathologically node-negative patients.

The prognostic significant of percentage drop in serum CEA post curative resection for colon cancer

OBJECTIVE/BACKGROUND

This study aimed to analyze the hypothesis that increased percentage drop in serum CEA post curative resection for colon cancer is associated with improved survival.

METHODS

Five hundred thirty three patients who underwent colon resection with a curative intent were retrospectively analyzed for their pre- and postoperative CEA levels. The disease-free and overall survival curves were calculated using Kaplan Meier analysis to evaluate cancer related outcomes. For multivariate analysis, the Cox regression model was used.

RESULTS

The estimated 5-year overall survival for the preoperative serum CEA > 5 ng/mL group with respect to a postoperative CEA level drop rate of 40%, 50% and 60% were 72.9%, 80.9% and 81.8%, respectively. The estimated 5-year overall survival for the preoperative serum CEA ≤ 5 ng/mL group with respect to each postoperative CEA level drop rate were 86.6%, 97.1% and 97.7%, respectively (P = 0.257, P = 0.092 and P = 0.073, respectively). The prognostic factors for poor survival were the depth of invasion (p = 0.042, hazard ratio: 2.617, 95% CI = 1.021-3.012) and lymph node metastasis (p = 0.008, hazard ratio: 2.249, 95% CI = 1.231-4.111). A 60% drop of the CEA level was an independent prognostic factor for survival (p = 0.001, hazard ratio: 2.954, 95% CI = 1.686-5.176) for patients with a preoperative CEA level > 5 ng/mL.

CONCLUSION

Determining the preoperative CEA level and the early postoperative percent drop of the serum CEA level may be a helpful factor for the prognosis of colon cancer patients. However, the percent drop from the pre to postoperative CEA level from the normal range was not associated with survival difference.

Microdevices integrating affinity columns and capillary electrophoresis for multibiomarker analysis in human serum

Biomarkers in human body fluids have great potential for use in screening for diseases such as cancer and diabetes, diagnosis, determining the effectiveness of treatments, and detecting recurrence. Present 96-well immunoassay technology effectively analyzes large numbers of samples; however, this approach is more expensive and less time effective on single or a few samples. In contrast, microfluidic systems are well suited for assaying small numbers of specimens in a point-of-care setting, provided suitable procedures are developed to work within peak capacity constraints when analyzing complex mixtures like human blood serum. Here, we developed integrated microdevices with an affinity column and capillary electrophoresis channels to isolate and quantitate a panel of proteins in complex matrices. To form an affinity column, a thin film of a reactive polymer was photopolymerized in a microchannel, and four antibodies were covalently immobilized to it. The retained protein amounts were consistent from chip to chip, demonstrating reproducibility. Furthermore, the signals from four fluorescently labeled proteins captured on-column were in the same range after rinsing, indicating the column has little bias toward any of the four antibodies or their antigens. These affinity columns have been integrated with capillary electrophoresis separation, enabling us to simultaneously quantify four protein biomarkers in human blood serum in the low ng mL(-1) range using either a calibration curve or standard addition. Our systems provide a fast, integrated and automated platform for multiple biomarker quantitation in complex media such as human blood serum.

Preoperative carcinoembryonic antigen level as an independent prognostic factor in potentially curative colon cancer

OBJECTIVE

We evaluated the prognostic value of the preoperative serum carcinoembryonic antigen (CEA) level in patients with colon cancer.

METHODS

We reviewed 474 patients who underwent potentially curative resection for nonmetastatic colon cancer. Patients were categorized into two groups according to the preoperative serum CEA level: low CEA (<5 ng/ml) and high CEA (>or=5 ng/ml) groups.

RESULTS

During the median 45-month follow-up period, the 5-year overall and disease-free survival rates for patients with a low CEA level were 81.7% and 82.4%, respectively, which were significantly higher than the rates for those with a high CEA level (69.9%; P = 0.011 and 70.6%; P = 0.002, respectively). A multivariate analysis revealed that a preoperative serum CEA level was a significant independent prognostic factor for both overall survival (P = 0.021) and disease-free survival (P = 0.026). Both the overall and disease-free survival rates in patients with stage II tumors differed significantly between the low and high CEA groups, whereas the rates did not different between those with stage I and III tumors.

CONCLUSIONS

Preoperative serum CEA is a reliable predictor of recurrence and survival after curative surgery in patients with colon cancer, particularly in those classified as having stage II disease.

Predictive factors of early relapse in UICC stage I-III colorectal cancer patients after curative resection

BACKGROUND AND OBJECTIVES

To predict the clinicopathologic factors for early relapse of UICC stage I-III colorectal cancer (CRC) patients undergoing curative resection and thus to identify a subgroup of patients who are at high risk for postoperative early relapse.

METHODS

Between January 2001 and June 2007, a total of 778 UICC stage I-III CRC patients who underwent a radical resection and regular follow-up were retrospectively analyzed. Of these 778 CRC patients, 521 colon cancer and 257 rectal cancer cases were analyzed, respectively, to determine the predictors of early relapse postoperatively. These 778 patients were followed-up intensively, and their outcomes were investigated retrospectively.

RESULTS

Out of 521 colon cancer patients, postoperative relapse after primary resection was found in 142 (27.3%) patients, and 77 (54.2%) of 142 recurrent colon cancer patients were classified as postoperative early relapse. Meanwhile, among 257 rectal cancer patients, postoperative relapse was found in 68 (26.5%) patients and 44 (64.7%) of 68 recurrent rectal cancer patients were identified as postoperative early relapse. Forty-nine (63.6%) of 77 early relapsed colon cancer patients were stage III, and likewise, 26 (59.1%) of 44 early relapsed rectal cancer patients were stage III. Univariately, postoperative early relapse of colon cancer patients was significantly correlated with the presence of vascular invasion (P < 0.001), perineural invasion (P < 0.001), high postoperative carcinoembryonic antigen (CEA) level (P = 0.001), and type of surgery (P = 0.016). Using a Cox proportional hazards analysis, the presence of vascular invasion (P = 0.033), perineural invasion (P = 0.005), and high postoperative CEA levels (P = 0.001) were demonstrated to be independent predictors of postoperative early relapse of colon cancer patients, while in rectal cancer patients, both vascular invasion (P = 0.039) and perineural invasion (P = 0.008) were statistically significant predictors of early relapse by univariate analysis. Using a Cox proportional hazards analysis, only perineural invasion (P = 0.043) was an independent factor. Early relapse cases had significant lower overall survival rates than non-early relapse cases either in colon cancer (P < 0.001) or in rectal cancer (P = 0.0091) patients.

CONCLUSIONS

This study suggests that vascular invasion, perineural invasion, and postoperative CEA level may be significant factors for postoperative early relapse of colon cancer; while only perineural invasion is considered to be a significant predictor in rectal cancer patients. Identification of these high-risk UICC stage I-III CRC patients of early relapse is important, and thus could help to define patients with this tumor entity for an enhanced follow-up and therapeutic program.

Prognostic value of postoperative CEA clearance in rectal cancer patients with high preoperative CEA levels

PURPOSE

We determined the prognostic value of carcinoembryonic antigen (CEA) clearance after tumor resection with serial evaluation of postoperative CEA levels in rectal cancer.

METHODS

Between 1994 and 2004, we retrospectively reviewed 122 patients with rectal cancer whose serum CEA levels were measured on the preoperative day and postoperative days 7 and 30. Patients with preoperative CEA levels <5.0 ng/ml were excluded. An exponential trend line was drawn using the three CEA values. Patients were categorized into three groups based on R(2) values calculated through trend line, which indicates the correlation coefficient between exponential graph and measured CEA values: exponential decrease group (group 1: 0.9 < R(2) < or = 1.0), nearly exponential decrease group (group 2: 0.5 < R(2) < or = 0.9), and randomized clearance group (group 3: 0.5 < or = R(2)). We then analyzed the CEA clearance pattern as a prognostic indicator.

RESULTS

With a median follow-up of 57 months, the 5-year overall survival was 62.3% vs. 48.1% vs. 25% and the 5-year disease-free survival was 58.6% vs. 52.7% vs. 25% among groups 1, 2, and 3 (P = 0.014, P = 0.027, respectively) in patients with stage III rectal cancer. For those with stage II rectal cancer, the 5-year overall survival rate of group 1 was significantly better than groups 2 and 3 (88.8% vs. 74.1%, respectively, P = 0.021).

CONCLUSIONS

The postoperative pattern of CEA clearance is a useful prognostic determinant in patients with rectal cancer. Patients with a randomized pattern of CEA clearance after tumor resection should be regarded as having the possibility of a persistent CEA source and may require consideration of intensive follow-up or adjuvant therapy.

Prognostic value of carcinoembryonic antigen level in rectal cancer treated with neoadjuvant chemoradiotherapy

BACKGROUND

The purpose of this study was to identify clinical and pathological parameters to improve prediction of disease-free survival (DFS) and overall survival (OS) in patients treated with neoadjuvant chemoradiotherapy for rectal cancer.

METHODS

Between July 1995 and May 2007, 148 patients with primary rectal adenocarcinoma received neoadjuvant chemoradiotherapy followed by mesorectal excision. Preoperative treatment included various protocols, UFT and leucovorin (28%) and oxaliplatin-based chemotherapy (72%). Clinical and pathological variables were evaluated in relation to patient outcomes.

RESULTS

Thirteen percent of patients achieved a complete pathologic response. No response or minimal response as defined by Dworak (Tumor Regression Grade 0/1) was observed in 30 patients (20%). At a median follow-up of 37 months, the 3-year DFS and OS were 64% and 83%, respectively. Pre-treatment serum carcinoembryonic antigen (CEA) level </= 2.5 ng/ml was associated with higher DFS (74 vs. 53%; p = 0.018), higher complete pathologic responses (21 vs. 9%; p = 0.05), and less recurrences (24 vs. 44%; p = 0.014).

CONCLUSION

The data suggest that a CEA level </= 2.5 ng/ml might be a predictor not only of tumor response, as has been suggested before, but also of DFS. This finding could be useful in the future to predict individual risk and to develop more aggressive or alternative strategies.

The role of carcinoembriogenic antigen in predicting response and survival to neoadjuvant chemoradiotherapy for distal rectal cancer

PURPOSE

Carcinoembriogenic antigen (CEA) is the most frequently used tumor marker in rectal cancer. A decrease in carcinoembriogenic antigen after radical surgery is associated with survival in these patients. Neoadjuvant chemoradiotherapy may lead to significant primary tumor downstaging, including complete tumor regression in selected patients. Therefore, we hypothesized that a decrease in CEA after neoadjuvant chemoradiotherapy could reflect tumor response to chemoradiotherapy, affecting final disease stage and ultimately survival.

METHODS

Patients with distal rectal cancer managed by neoadjuvant chemoradiotherapy and available pretreatment and postchemoradiotherapy levels of CEA were eligible for the study. Outcomes studied included final disease stage, relapse, and survival, and these were compared according to initial CEA level, post-chemoradiotherapy CEA level, and the reduction in CEA.

RESULTS

Overall 170 patients were included. Post-chemoradiotherapy CEA levels <5 ng/ml were associated with increased rates of complete clinical response and pathologic response. Additionally, postchemoradiotherapy CEA levels <5 ng/ml were associated with increased overall and disease-free survival (P = 0.01 and P = 0.03). There was no correlation between initial CEA level or reduction in CEA and complete response or survival.

CONCLUSION

A postchemoradiotherapy CEA level <5 ng/ml is a favorable prognostic factor for rectal cancer and is associated with increased rates of earlier disease staging and complete tumor regression. Postchemoradiotherapy CEA levels may be useful in decision making for patients who may be candidates for alterative treatment strategies.

Risk factors for local recurrence of middle and lower rectal carcinoma after curative resection

AIM: To explore the risk factors for local recurrence of middle and lower rectal carcinoma after curative resection.

METHODS: Specimens of middle and lower rectal carcinoma from 56 patients who received curative resection at the Department of General Surgery of Guangdong Provincial People’s Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. The relations between clinicopathologic characteristics, mesorectal metastasis and circumferential resection margin status were identified in patients with local recurrence of middle and lower rectal carcinoma.

RESULTS: Local recurrence of middle and lower rectal carcinoma after curative resection occurred in 7 of the 56 patients (12.5%), and was significantly associated with family history (χ² = 3.929, P = 0.047), high CEA level (χ² = 4.964, P = 0.026), cancerous perforation (χ² = 8.503, P = 0.004), tumor differentiation (χ² = 9.315, P = 0.009) and vessel cancerous emboli (χ² = 11.879, P = 0.001). In contrast, no significant correlation was found between local recurrence of rectal carcinoma and other variables such as age (χ² = 0.506, P = 0.477), gender (χ² = 0.102, χ² = 0.749), tumor diameter (χ² = 0.421, P = 0.516), tumor infiltration (χ² = 5.052, P = 0.168), depth of tumor invasion (χ² = 4.588, P = 0.101), lymph node metastases (χ² = 3.688, P = 0.055) and TNM staging system (χ² = 3.765, P = 0.152). The local recurrence rate of middle and lower rectal carcinoma was 33.3% (4/12) in patients with positive circumferential resection margin and 6.8% (3/44) in those with negative circumferential resection margin. There was a significant difference between the two groups (χ² = 6.061, P = 0.014). Local recurrence of rectal carcinoma occurred in 6 of 36 patients (16.7%) with mesorectal metastasis, and in 1 of 20 patients (5.0%) without mesorectal metastasis. However, there was no significant difference between the two groups (χ² = 1.600, P = 0.206).

CONCLUSION: Family history, high CEA level, cancerous perforation, tumor differentiation, vessel cancerous emboli and circumferential resection margin status are the significant risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. Local recurrence may be more frequent in patients with mesorectal metastasis than in patients without mesorectal metastasis.

Diagnostic precision of carcinoembryonic antigen in the detection of recurrence of colorectal cancer

INTRODUCTION

The aim of the study was to evaluate the diagnostic precision of serum carcinoembryonic antigen (CEA) in the detection of local or distant recurrence following resectional surgery for colon and rectal cancer.

METHODS

Quantitative meta-analysis was performed on 20 studies, comparing serum CEA with radiological imaging and/or pathology in detecting colorectal cancer (CRC) recurrence in 4285 patients. The cut-off for a 'positive' CEA ranged from 3 to 15 ng/ml between the various studies. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver operating characteristic curves (SROC) and sub-group analysis were undertaken.

RESULTS

The overall sensitivity and specificity of CEA for detecting CRC recurrence was 0.64 (95% CI: 0.61-0.67) and 0.90 (95% CI: 0.89-0.91), respectively. The area under the SROC curve was 0.75 (SE=0.04) and the diagnostic odds ratio was 18.44 (95% CI: 11.94-28.49). A CEA cut-off of 5 ng/ml yielded a higher diagnostic odds ratio than a cut-off of 3 ng/ml (15.5 vs. 11.1). Using meta-regression analysis the optimum CEA cut-off point for the best combination of sensitivity and specificity was 2.2 ng/ml. On sub-group analysis high quality studies, and those involving > or =100 patients yielded a marginal improvement in the sensitivity and specificity with minimal change to the SROC.

CONCLUSION

Serum CEA is a test with high specificity but insufficient sensitivity for detecting CRC recurrence in isolation. A cut-off of 2.2 ng/ml may provide an ideal balance of sensitivity and specificity. It may be useful as a first-line surveillance investigation in patients during surgical follow-up based on serial CEA measurements using temporal trends in conjunction with clinical, radiological and/or histological confirmation.

Positron emission tomography/computer tomography in guidance of extrahepatic hepatocellular carcinoma metastasis management

Hepatocellular carcinoma (HCC) is one of the most common primary cancers in the world. Surgery is the gold standard for treatment of patients with HCC. Recurrence and metastasis are the major obstacles to further improve the prognosis of HCC. Most recurrences are intrahepatic. However, 30% of the recurrences are extrahepatic. The role of resection in intrahepatic recurrences is widely accepted. The role of resection in extrahepatic HCC recurrence and metastasis is not well established. 18F fluorodeoxyglucose (18F-FDG) positron emission tomography/computer tomography (PET/CT) is useful in detecting distant metastasis from a variety of malignancies and shows superior accuracy to conventional imaging modalities in identification of intrahepatic and extrahepatic metastasis. We present one patient with one new isolated omental lymph node metastasis, who had a history of huge HCC resected six years ago. The metastatic focus was identified with 18 F-FDG PET/CT and resected. The follow-up revealed good prognosis with a long-term survival potential after resection of the omental lymphatic metastasis.

Positron emission tomography/computer tomography: Challenge to conventional imaging modalities in evaluating primary and metastatic liver malignancies

Computer tomography (CT) and magnetic resonance imaging (MRI), as conventional imaging modalities, are the preferred methodology for tumor, nodal and systemic metastasis (TNM) staging. However, all the noninvasive techniques in current use are not sufficiently able to identify primary tumors and even unable to define the extent of metastatic spread. In addition, relying exclusively on macromorphological characteristics to make a conclusion runs the risk of misdiagnosis due mainly to the intrinsic limitations of the imaging modalities themselves. Solely based on the macromorphological characteristics of cancer, one cannot give an appropriate assessment of the biological characteristics of tumors. Currently, positron emission tomography/computer tomography (PET/CT) are more and more widely available and their application with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using ¹⁸F-FDG, PET and PET/CT in order to establish diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. PET/CT with ¹⁸F-FDG as a radiotracer may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from hepatic metastases, hepatocellular carcinoma and cholangiocarcinoma.