Reoperation directed by carcinoembryonic antigen level: the importance of a thorough preoperative evaluation

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).

Carcinoembryonic Antigen in the Staging and Follow-up of Patients with Colorectal Cancer

CEA is a complex glycoprotein produced by 90% of colorectal cancers and contributes to the malignant characteristics of a tumor. It can be measured in serum quantitatively, and its level in plasma can be useful as a marker of disease. Because of its lack of sensitivity in the early stages of colorectal cancer, CEA measurement is an unsuitable modality for population screening. An elevated preoperative CEA is a poor prognostic sign and correlates with reduced overall survival after surgical resection of colorectal carcinoma. A failure of the CEA to return to normal levels after surgical resection is indicative of inadequate resection of occult systemic disease. Frequent monitoring of CEA postoperatively may allow identification of patients with metastatic disease for whom surgical resection or other localized therapy might be potentially beneficial. To identify this group, serial CEA measurement appears to be more effective than clinical evaluation or any other diagnostic modality, although its sensitivity for detecting recurrent disease is not as high for locoregional or pulmonary metastases as it is for liver metastases. Several studies have shown that a small percentage of patients followed postoperatively with CEA monitoring and who undergo CEA-directed salvage surgery for metastatic disease will be alive and disease-free 5 years after surgery. Furthermore, CEA levels after salvage surgery do appear to predict survival in patients undergoing resection of liver or pulmonary metastases. However, several authors argue that CEA surveillance is not cost-effective in terms of lives saved. In support of this argument, there is no clear difference in survival after resection of metastatic disease with curative intent between patients in whom the second-look surgery was performed on the basis of elevated CEA levels and those with other laboratory or imaging abnormalities. There is also no clear consensus on the frequency or duration of CEA monitoring, although the ASCO guidelines currently recommend every 2-3 months for at least 2 years after diagnosis. In the follow-up of patients undergoing palliative therapy, the CEA level correlates well with response, and CEA is indicative of not only response but may also identify patients with stable disease for whom there is also a demonstrated benefit in survival and symptom relief with combination chemotherapy. More recently, scintigraphic imaging after administration of radiolabeled antibodies afforded an important radionuclide technique that adds clinically significant information in assessing the extent and location of disease in patients with colorectal cancer above and beyond or complementary to conventional imaging modalities. Immunotherapy based on CEA is a rapidly advancing area of clinical research demonstrating antibody and T-cell responses.

A cost-effectiveness approach to the Norwegian follow-up programme in colorectal cancer

BACKGROUND

Today, continued periodic follow-up of patients treated for colorectal cancer (CRC) seems often to be routine because of tradition, rather than its demonstrated value. Recently, the Norwegian Gastrointestinal Cancer Group (NGICG) has recommended a standard surveillance programme in this malignancy. In this protocol patients are suggested followed for four years with CEA monitoring, ultrasound of the liver, chest radiograph and colonoscopy at regular intervals.

MATERIALS AND METHODS

In this study, the cost-effectiveness of this programme was addressed employing Norwegian cost data and data from the Cancer Registry of Norway. Clinical data from the existing English language literature was used in the analysis.

RESULTS

The basic cost of the NGICG recommended programme was 1,232 Pounds per patient. Including extended investigation due to suspected relapse in 45% of cases, the figure raised to 1,943 Pounds per patient. The cost per life year saved was indicated to 9,525 Pounds-16,192 Pounds. The corresponding cost per quality adjusted life year (QALY) was indicated to 11,476 Pounds-19,508 Pounds.

CONCLUSION

We conclude the NGICG recommended follow-up programme in CRC cost-effective. Excluding CEA monitoring may improve the cost-effectiveness.

CAM 17.1--a new diagnostic marker in pancreatic cancer

CAM 17.1-Ab is a recently described monoclonal antibody that detects a mucus glycoprotein with high specificity for intestinal mucus, particularly in the colon, small intestine, biliary tract and pancreas. We investigated the expression and release of CAM 17.1 in pancreatic carcinoma cell lines and tissue specimens of normal pancreas, chronic pancreatitis and pancreatic cancer. CAM 17.1 was weakly expressed on normal ductal cells and chronic pancreatitis, whereas it was overexpressed in pancreatic cancer. Serum analysis using a new enzyme-linked antibody sandwich assay (CAM 17.1/WGA) of patients with chronic pancreatitis, pancreatic cancer or other gastrointestinal cancer and of healthy blood donors revealed a high sensitivity (67%) and excellent specificity (90%) of CAM 17.1/WGA assay in pancreatic cancer. In comparison with the tumour marker CA19-9, the sensitivity of the CAM 17.1/WGA assay was similar to the sensitivity of CA 19-9 (67% and 76%, P = 0.22), whereas the specificity of CAM 17.1/WGA assay was higher than in CA 19-9 (90% compared with 78% in chronic pancreatitis, P > 0.05).

The use of prognostic markers in surgery for colorectal cancer

The basis for prognostic prediction after surgery for colorectal cancer remains the various pathological staging systems based on that of Dukes. Serum prognostic markers have not shown significant independent prognostic power compared with these predictive tools. Much energy has been expended in examining the ability of serum markers to predict recurrent tumour prior to the onset of symptoms. Carcinoembryonic antigen (CEA) has been a particular subject of attention, and has been widely, though variably, advocated as a useful predictor in these circumstances. It has been estimated that around half a million Americans are presently undergoing regular postoperative CEA monitoring to this end. Controversy continues regarding the therapeutic utility of such monitoring. This may be resolved when the results of the only randomised trial in the field are published in the near future. No other serum marker, nor any combination of markers, has been shown clearly to be superior to CEA as a predictor of recurrent tumour.

The value of serum carcinoembryonic antigen in predicting recurrent disease following curative resection of colorectal cancer

Carcinoembryonic antigen (CEA) estimations are used to facilitate early diagnosis of recurrent disease after treatment for colorectal cancer.

PURPOSE

This study was designed to determine the natural history of patients with normal and abnormal levels of CEA.

METHODS

Patients undergoing potential curative resection of colorectal tumors (Dukes Stage A-C) entered a prospective, randomized trial comparing two follow-up regimens (to be reported separately) had CEA levels measured every 3 months for two years; then every 6 months for the next three years. In the study protocol, a rise in CEA was not an indication for investigation to determine recurrence unless there was also other evidence of recurrent disease.

RESULTS

Three hundred eleven patients were followed for a median of 4.5 (range, 2-5) years. Recurrent disease developed in 98 (32 percent) patients, 57 of whom had an elevated CEA (sensitivity 58 percent), with a median lead time of six (range, 1-30) months from first abnormal CEA to diagnosis of recurrent disease by other means. The specificity, positive predictive value, and negative predictive value of CEA as an indicator of subsequent recurrent disease was 93 percent, 79 percent, and 83 percent, respectively. The sensitivity of CEA for predicting hepatic metastases was 80 percent, with a median lead time of eight (range, 1-30) months, compared with only 46 percent for sites of recurrent disease other than the liver.

CONCLUSIONS

CEA was the first indicator of recurrent disease in 58 percent of all patients and in 80 percent of patients with liver metastases. The diagnosis of recurrent disease may be made several months earlier by investigating the first abnormal CEA level, although any benefit in terms of survival remains to be proven.

Optimal follow-up in colorectal cancer patients: what tests and how often?

Patients' benefit from follow-up examinations after curative surgery for colorectal cancer is unproven in spite of numerous different programs' having been designed for that purpose. Unfortunately, no final results from prospective randomized studies have been published yet and no ideal marker for recurrent cancer is available to identify patients in whom new curative treatment may be possible. So far, screening for metachronous neoplasia with intervals of several years may influence survival, whereas benefit from detecting recurrent colorectal cancer may be claimed only by using historical or other inappropriate controls. The tradition of follow-up is expensive and prospective evidence for any cost benefit is needed to justify continuous use of our limited resources in this area of patient care.

CA 494--a new tumor marker for the diagnosis of pancreatic cancer

In 59 patients with ductal pancreatic cancer the monoclonal antibody (MAb) BW 494, which detects the CA 494 glycoprotein antigen, was analyzed in comparison with the reference tumor markers CA 19-9 and CEA. Eighty-one patients with non-pancreatic malignancies of the gastrointestinal (GI) tract, 95 with chronic pancreatitis, 124 with benign non-pancreatic GI diseases, 30 with diabetes mellitus (type I or type II) and 114 healthy blood donors served as controls. The sensitivity of pancreatic cancer was 90%, 44% and 90% for CA 19-9, CEA and CA 494, respectively. In chronic pancreatitis, as the most important control population for pancreatic cancer, the specificity was 85%, 72% and 94% for CA 19-9, CEA and CA 494, respectively.

Colorectal cancer. Principles of postoperative follow-up

Monitoring patients after primary large bowel surgery for malignancy is predicated on the concept that early detection of recurrence may provide salvage treatment for cure. Knowledge of the pathologic site and stage provides important information as to the probability of recurrence and the patterns of failure that are likely to occur. Available methods to detect recurrence include clinical, roentgenographic, and serum tests that are done more frequently during the first 2 years after surgery. Monitoring plasma carcinoembryonic antigen levels can lead to identification of asymptomatic recurrences, but there is controversy about the curability of recurrences outside the liver. Newer techniques (such as computed tomographic portography, intraoperative ultrasonography, and radioimmunoguided surgery) provide greater diagnostic accuracy and lead to more appropriate procedures during "second-look" operations. For example, hepatic resection in properly selected patients offers up to a 30% chance of cure and should be pursued aggressively. A search for metachronous cancers by endoscopy also should be done. Knowledge of the potential and patterns of failure can provide a useful guide during the postoperative follow-up care of the patient with large bowel cancer.

Role of CEA, TPA, and Ca 19-9 in the early detection of localized and diffuse recurrent rectal cancer

Sixty-six consecutive patients who underwent curative resection for rectal cancer were studied prospectively to evaluate the roles of sequential carcinoembryonic antigen (CEA), tissue plasminogen activator (TPA), and carcinomatous antigen 19-9 (Ca 19-9) determinations in the early diagnosis of resectable recurrences. Thirty-three recurrences were detected between 6 and 42 months. CEA, TPA, and Ca 19-9 showed a sensitivity of 72.7 percent, 78.8 percent, and 60.1 percent, respectively, and a specificity of 60.6 percent, 60.6 percent, and 87.9 percent, respectively. In 23 cases the rise in the value of CEA and/or TPA and/or Ca 19-9 was the first sign of recurrences, and the diagnosis was established later by clinical methods. In this group, the lead time was two months for liver metastases and four months for disseminated metastases. As far as the relationship between localization of recurrence and marker level increase is concerned, of 16 hepatic metastases CEA, TPA, and Ca 19-9 showed a sensitivity of 94 percent (P less than 0.05), 69 percent, and 62 percent, respectively. Of six patients with local recurrences, CEA, TPA, and Ca 19-9 showed a sensitivity of 50 percent, 100 percent (P less than 0.05), and 83.3 percent, respectively. Of three patients with peritoneal carcinomatosis, CEA, TPA (P less than 0.05), and Ca 19-9 showed a sensitivity of 0 percent, 100 percent, and 0 percent, respectively. No significant differences were reported among the three markers according to multiple metastases and metachronous polyps. Fourteen patients (42.4 percent) underwent surgical treatment for recurrent disease, and eight of them (57 percent) showed a resectable disease, for a total resectability rate of 24.2 percent. The findings of our study indicate that a follow-up program based on CEA, TPA, and Ca 19-9 assays is related to an early diagnosis and a good resectability rate for both local and metastatic recurrences from rectal cancer.

Early results of follow-up after radical resection for colorectal cancer. Preliminary results of a prospective randomized trial

One-hundred and six consecutive patients were included in a prospective study of intensive monitoring after radical resection for colorectal cancer, 54 being randomized into a conventional follow-up group (Group I) and 52 into an intensified follow-up group (Group II). After a median follow-up of 2 years the overall rate of detection recurrence in Group I was 24% (13/54) and in Group II 25% (13/52). The recurrence rates among those followed up for at least 2 years were 36% (10/28) and 30% (9/30), respectively. Of the recurrences in Group I, one was local, five regional and six distant, and the corresponding figures in Group II were three, four and five. One radical extirpation of a local perineal recurrence has been performed in Group I, whereas two intestinal reresections for local anastomotic recurrences and two hepatic resections for solitary hepatic metastases have been performed in Group II. Mortality to date is 13% (7/54) in Group I and 8% (4/52) in Group II. Two adenomatous polyps have been removed from the colon in Group I during endoscopic surveillance and seven in Group II. These preliminary results encourage us to continue the trial up to 5 years after primary surgery.

Cost-effective management of colon and rectal cancer

Health care costs in the United States of America continue to rise. Legislators, economists and third party payers are becoming increasingly concerned with intervention outcomes and the distribution of resources. It is the responsibility of the medical profession to assume a leading role in assessing the cost-effectiveness of health care interventions. Although many physicians perform informal cost-effectiveness analyses on a daily basis, health economists employ a variety of more complex methodologies. This article will attempt to provide physicians with an understanding of the value and limitations of the tools used in formal cost-effectiveness analyses and demonstrate how these tools may be applied to the management of colon and rectal cancer.

Excision of pulmonary metastasis of colorectal cancer

Metastasis of colorectal cancer to the lung is a frequent occurrence. Resection of pulmonary metastasis provides the only effective treatment. The initial detection of disease is usually with a chest radiograph. A CAT scan determines the number of lesions, resectability and other metastatic disease. Candidates for surgical excision are those patients with completely resectable singular, multiple, and bilateral metastasis, and those with metachronous liver lesions excised for cure. Exposure of unilateral disease is via a thoracotomy and of bilateral disease via a sternotomy. Metastatic lesions are removed by wedge resection with conservation of lung tissue. Postoperative recovery is usually rapid with low morbidity and mortality. Long-term success for these resections remains controversial.

Colon, rectum, and anus

Cancer of the colon is the second most common cancer. Adherence to principles of screening, diagnosis, and management have the potential to substantially improve survival.

Update on colorectal cancer. Risk factors, diagnosis, and treatment

Colorectal cancer is more common in the Western world than in underdeveloped countries. Diet, longevity, heredity, and presence of other bowel diseases may affect the incidence. Diagnosis is based on results of routine laboratory studies and evaluation of the entire large bowel with air-contrast barium enema and colonoscopy. Surgical resection is the primary therapy for colorectal cancer. Postoperative systemic chemotherapy yields poor results, but hepatic artery infusional chemotherapy offers some benefit to patients who have only hepatic metastases. Follow-up evaluation includes physical examination and laboratory studies every 3 months for the first 2 years and colonoscopy every year.