Detection Of Recurrent Colorectal Cancer Research Articles

Serum carcinoembryonic antigen measurement, abdominal contrast-enhanced computed tomography, and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of colorectal cancer recurrence

The aim of this study was to evaluate the correlative role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in carcinoembryonic antigen (CEA) measurement and contrast-enhanced abdominal computed tomography (ceCT) in the detection of colorectal cancer (CRC) recurrence. A total of 96 patients (40 female, 56 male; mean age, 60.6 ± 12 years) with a previous diagnosis of CRC underwent 18F-FDG PET/CT on suspicion of recurrence and were evaluated retrospectively. Inclusion criteria were accepted as the presence of increased serum CEA levels or positive findings on abdominal ceCT or both. 18F-FDG PET/CT findings were compared with histopathological findings and/or clinical follow-up data as the gold standard. Patients were divided into three groups: group 1, with increased CEA levels and normal abdominal ceCT; group 2, with normal CEA levels and positive ceCT; and group 3, with increased CEA levels and positive ceCT. Whereas sensitivities of CEA, ceCT, and 18F-FDG PET/CT in the three patient groups were calculated as 91, 67, and 96%, specificities were 13, 51, and 62%, respectively. There were 35, 14, and 46 patients in groups 1, 2, and 3, respectively. In separate analyses conducted on the groups, sensitivity of 18F-FDG PET/CT was computed as 100 and 100% and specificity as 88 and 80% for groups 1 and 2. In group 3, which comprised four patients with secondary malignancies, sensitivity and specificity of 18F-FDG PET/CT were 94 and 16%, respectively. 18F-FDG PET/CT has an additional role in the detection of CRC recurrence with a higher sensitivity compared with CEA and ceCT alone, and 18F-FDG PET/CT is especially more successful in patients with isolated elevated CEA levels or positive ceCT findings without accompanying CEA elevation.

Elevated CEA level in the asymptomatic patient with normal conventional imaging: How useful is PET-CT for the detection of colorectal cancer recurrence?

400 Background: Serum carcinoembryonic antigen (CEA) level can be used as a sensitive marker of recurrence in the follow up of patients with colorectal carcinoma, enabling the early detection of recurrent disease at a stage where further curative therapy may be possible. However a subset of patients with asymptomatic elevated CEA levels will have no evidence of disease recurrence on conventional imaging (CI). Aim: The purpose of this study was to evaluate the utility of 18F-FDG PET CT in detecting occult disease recurrence where CI has failed to demonstrate a cause for a rise in CEA. Methods: 88 consecutive patients on surveillance following treatment for colorectal cancer with an elevation in CEA level (>3ng/ml non-smokers, >5ng/ml smokers) with normal (67) or equivocal (21) findings on conventional imaging (defined as CT+/-MRI, ultrasound or colonoscopy) who had undergone PET-CT between 01.01.2004 and 31.08.2010 were retrospectively identified. Histopathological confirmation or a minimum of 12 months of follow up were used to ascertain disease relapse. Eligibility for further curative treatment was established from clinical notes. Results: Recurrent disease was detected in 56/88 patients (prevalence 64%). The sensitivity of PET-CT to detect recurrence was 49/56 (88%, 95% CI 76-94) and specificity 28/32 (88%, 95% CI 72-95). The positive predictive value (PPV) and negative predictive value (NPV) for recurrence was 93% and 80% respectively. Sensitivity in subgroups with CEA levels 3-6, 6-10 and > 10ng/ml were 91%, 82% and 89% respectively. 27 out of 49 patients (55%) with relapsed disease were eligible for further curative therapy and 26 received treatment with curative intent. The commonest site for PET detected disease relapse was the liver (16/49, 33%). Conclusions: PET-CT is a highly sensitive and specific tool for the detection of occult colorectal cancer recurrence in patients with raised CEA and normal CI thus should be considered mandatory in this setting. In over 50% of patients the recurrent disease detected before CI is positive, is still amenable for curative therapy.

A new strategy for the early detection of colorectal cancer recurrence.

416 Background: Several biological markers have been tested for colorectal cancer (CRC) including CEA; however, they are of limited use for recurrence diagnosis due to low sensitivity. Almost 50% of CRC cases experience recurrence and more than 50% of them have low values not detectable by CEA. Therefore, an effective marker for detection of recurrence will vastly increase the quality of life and survival rate. Onko-Sure is an FDA-cleared blood test that is used for the monitoring of treatment/recurrence of CRC. This ELISA assay measures the accumulation of Fibrin/Fibrinogen Degradation products in the serum using an antibody against the DR-70. The goal of this study was to determine whether the combined usage of DR-70 and CEA will improve the sensitivity for detecting recurrences. Methods: A total of 75 serum samples were retrospectively recruited through a serum bank in two arms including the confirmed healthy control (n=39) and biopsy-confirmed recurrent CRC (n=36) groups. For each patient, the serum sample was tested for DR-70 and CEA concentrations. Results: The results showed sensitivity of 75% and specificity of 58.97% for DR-70 and CEA combined. The cut points were calculated as 1.3ug/ml for DR-70, and 3 or 5ng/ml for CEA for non-smokers and smokers; respectively. For the combined analysis, if either CEA or DR-70 was positive, the test was considered positive and if both tests were negative, the result was considered negative. The sensitivity for the combined test was much better than that of each of the markers alone (35% higher than that of CEA). Conclusions: The combined usage of DR-70 and CEA in monitoring of CRC recurrence showed a significant clinical advantage in terms of sensitivity over each marker alone. Improvement in detection of recurrence has important implications to patient treatment options and prognosis. Should an IVD increase early detection of CRC recurrence when used adjunctively with other available diagnostic markers, the annual deaths due to CRC recurrence could be reduced due to the increase in early detection and the survival rate of those early detections.

Clinical impact of fluorodeoxyglucose-positron emission tomography scan/computed tomography in comparison with computed tomography on the detection of colorectal cancer recurrence

Early detection is an essential prognostic factor in colorectal cancer (CRC) recurrence. Our aim was to evaluate diagnostic performances of (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET)/computed tomography (CT) as compared with CT in the detection of CRC recurrence. Data of patients with suspected CRC recurrence and in whom both FDG-PET/CT and CT were performed were analyzed. All detected lesions were characterized according to their number, size, and localization. Positive histological or radiological follow-up was considered as the 'gold standard'. Diagnostic performances of FDG-PET/CT and CT were calculated by lesion, globally and with respect to the site of recurrence. One hundred and seventy-six true-positive lesions were identified in 71 patients. CT scan was positive in 58 (82%) patients and FDG-PET/CT in 70 (98%) patients. In per lesion analysis, the global accuracy of FDG-PET/CT in detection of lesions was of 88% (sensitivity = 95%, specificity = 54%), which was higher than that of CT (53%, sensitivity = 55%, specificity = 43%), particularly in case of lymph nodes metastases (100 vs. 35%) and locoregional lesions (100 vs. 39%) (P<0.0001). FDG-PET/CT modified the clinical management in 31 patients. FDG-PET/CT is more sensitive than CT for diagnosis of CRC recurrence and can modify the management in 40% of patients.

Positron emission tomography scanning is coming to a hospital near you soon!

Positron emission tomography (PET) is still generally not available in the UK; however, there are plans to introduce a national service in England from April 2008. Plans are also at an advanced stage in Scotland and Wales. The main uses of PET are in preoperative staging of lung cancer, detection of recurrent colorectal cancer, and management of patients with lymphoma. Although these provide the bulk of the referral base, PET is also of use in specific situations in patients with less common cancers, such as head and neck cancer, gynaecological cancer, and melanoma. In its more common uses, PET has been shown to be cost effective. Positron emission tomography will play an increasing role in the evaluation of response to treatment to enable early separation of patients who are responding well to chemotherapy from those who are not responding and need to be transferred to another therapy.

The role of FDG-PET/CT in the detection of recurrent colorectal cancer

The conventional diagnostic techniques used to assess recurrence of colorectal cancer (CRCR) often yield unspecific findings. Integrated FDG-PET/CT seems to offer promise for the differential diagnosis of benign and malignant lesions. The aim of this study was to compare the value of FDG-PET and PET/CT in the detection of CRCR subsequent to colonic resection or rectal amputation. The population for this retrospective study comprised 84 patients with suspected CRCR. The sensitivity, specificity and accuracy of PET and PET/CT were calculated for (a) intra-abdominal extrahepatic recurrences, (b) extra-abdominal and/or hepatic recurrences and (c) all recurrences, and tumour marker levels were analysed. The sensitivity, specificity and overall accuracy of PET in detecting intra-abdominal extrahepatic CRCR were 82%, 88% and 86%, respectively, compared with 88%, 94% and 92%, respectively, for PET/CT. The corresponding figures for detection of extra-abdominal and/or hepatic CRCR were 74%, 88% and 85% for PET and 95%, 100% and 99% for PET/CT. Considering the entire population, the sensitivity, specificity and overall accuracy of PET were 80%, 69% and 75%, respectively, compared with 89%, 92% and 90%, respectively, for PET/CT. FDG-PET/CT examination correctly detected 40 out of a total of 45 patients with CRCR. Two of five patients with falsely negative FDG-PET/CT findings had local microscopic recurrences and one had miliary liver metastases. Of 39 patients without CRCR, three showed false positive FDG-PET/CT results. Two of these cases were due to increased accumulation in inflammatory foci in the bowel wall, while one was due to haemorrhaging into the adrenal gland. FDG-PET/CT appears to be a very promising method for distinguishing a viable tumour from fibrous changes, thereby avoiding unnecessary laparotomy.

FGD-PET in the follow-up of recurrent colorectal cancer.

The current methods of detection of recurrent colorectal cancer after surgical treatment are inaccurate using conventional imaging. This study set out to detect early recurrence by means of PET in patients treated surgically for colorectal cancer by curative resection. Thirty-one disease-free patients were recruited and underwent FDG-PET. The results were verified by clinical, surgical and radiological follow up and/or biopsy to evaluate the accuracy for detecting recurrence. PET detected 6 sites of increased activity in 5 patients. Three of these underwent surgery. One was false positive with no evident tumour and two underwent an hepatic resection with removal of a homental metastasis. The sensitivity was 100% and specificity 83.3%. Clinical management was altered in two cases (6.4%). This study demonstrates that PET is more accurate than conventional imaging for the evaluation of recurrence in colorectal cancer patients. FDG-PET should be considered in the follow-up of patients after treatment for colorectal cancer in addition to other imaging methods.

The value of immunoscintigraphy in the detection of recurrent colorectal cancer.

The aim of this prospective study was to determine whether anti-carcinoembryonic antigen (anti-CEA) scintigraphy is a useful additional technique in the diagnosis recurrence of colorectal cancer. Forty patients with suspected recurrence of colorectal cancer, underwent immunoscintigraphy (IS) and helical computed tomography (CT) in the 2 weeks before surgery. Surgical findings were used to evaluate the performance of the imaging techniques. Suspected areas on IS and CT were systematically explored. Helical CT was found to be superior to IS for the liver, the sensitivity and specificity of CT being 100% and 90%, respectively, vs 53% and 100% for IS. However, IS was better than CT for the detection of extra-hepatic abdominal recurrence: sensitivity and specificity of IS were 100 and 82% respectively vs 33 and 82% for CT. Seven cases of peritoneal carcinomatosis were overlooked by helical CT. Our results indicate that IS improves detection of extra-hepatic abdominal recurrence of colorectal cancer. Immunoscintigraphy is valuable as a guide to the treatment strategy and operative procedures.

Study of Carcinoembryonic Antigen Tissue Expression in Colorectal Cancer

Aim: The aim of our study was to determine to what extent serial carcinoembryonic antigen (CEA) is helpful in detecting colorectal cancer recurrence. Second major objectives of this study were to evaluate tissue staining with CEA monoclonal antibody and its pattern of distribution in malignant tissue as regards its relation to prognostic value. Patients and Methods: 30 colorectal cancer patients undergoing clinically curative operations were studied. Primary tumors were evaluated for tissue CEA using immunohistochemical staining with CEA monoclonal antibody. Preoperative serum CEA level was measured as well as in follow-up monitoring of the patients. Results: The exact preoperative serum CEA value did not correlate with tumor stage, grade and immunohistochemical intensity or pattern. In the ten patients who developed recurrent cancer, the serum CEA at recurrence was greater than 5 ng/ml in 80%. All such patients with recurrent tumor had CEA present in their primary tumor. There was no correlation with exact preoperative serum CEA, the intensity of the primary tissue CEA, or localization of such CEA. Conclusion: Tissue CEA is a useful marker in prediction of tumor recurrence. Also serum CEA is a useful marker in detection of recurrent colorectal cancer.

Effect of radioimmunoscintigraphy on the management of recurrent colorectal cancer.

Radioimmunoscintigraphy (RIS) is being used increasingly as a new investigation in the diagnosis of recurrent colorectal cancer. This study assessed the efficacy of 99mTc-radiolabelled PR1A3 scanning in a cohort of patients with possible recurrent colorectal cancer and the effects of scan interpretation on subsequent clinical management. The scans and case notes of patients scanned over a 3-year period were reviewed. Forty-seven scans in 40 patients were available for analysis. In 39 instances in which scan interpretation could be verified accurately, sensitivity for recurrent colorectal cancer was 22 of 23 (96 per cent), specificity for recurrent colorectal cancer was eight of 16 (50 per cent), positive predictive value for recurrence was 22 of 30 (73 per cent) and negative predictive value for recurrence was eight of nine (89 per cent). In 16 of the 40 patients, scan interpretation strengthened a management decision or altered management. This was beneficial to ten patients and possibly detrimental to six. This study demonstrated that RIS is sensitive in the detection of recurrent colorectal cancer and benefited the patient in one-quarter of cases. For the majority of patients, accurate detection of recurrent disease cannot be followed by curative therapy, but there is an important subgroup of patients in whom RIS alters management beneficially. However, a randomized prospective study is needed to confirm this.

COLORECTAL CANCER: Radiologic Staging

The role of conventional CT scan and conventional MR imaging in assessing patients with colorectal tumors is now well established. Because both techniques have an unacceptably low accuracy for identifying the early stages of primary colorectal cancers (T1, T2N0 or N1 and early T3N0 or N1, or Dukes stage A, B1 and 2, and C1), their routine use for preoperative staging is not recommended. This low staging accuracy is related to the fact that neither method can assess the depth of tumor infiltration within the bowel wall and both have difficulty in diagnosing malignant adenopathy. These distinctions are necessary in order to determine correctly patient prognosis and tumor resectability. If the various publications on CT scan and MR imaging staging of primary colon tumors are summarized, a mean overall accuracy of approximately 70% can be established. The sensitivity for lymph node detection of malignant lymphadenopathy is only about 45%. The sensitivity for detection of positive lymph nodes is better for rectal tumors because any adenopathy in the perirectal area can be considered malignant because benign adenopathy is not seen in this area. For the early stages of colon cancer or recurrent tumor at the anastomotic site, endoscopic ultrasound or TRUS is the method of choice. Both TRUS and MR imaging with endorectal coils can demonstrate the various layers of the rectal wall, but the ultrasonographic examination can be performed at lower cost and is less time-consuming. Despite these limitations CT scan and MR imaging are useful for assessing patients suspected of having extensive disease, including invasion of fat or neighboring organs or metastatic spread to distant sites including, liver, adrenals, lung, and so forth. CT scan and MR imaging are also helpful in the following ways: in determining whether a patient will benefit from preoperative radiation or whether a patient with rectal cancer can undergo a sphincter-saving procedure; for designing radiation ports; and for detecting complications related to the neoplasm, such as perforation with abscess formation or preobstructive ischemia in patients with complete obstruction by tumor. In these cases, management often is based on CT scan and MR imaging findings and cross-sectional follow-up studies can establish the success of treatment. CT scan and MR imaging have a premier role in the detection of recurrent colorectal cancer. CT scan and MR imaging are superior to colonoscopy for diagnosing extrinsic masslike tumor recurrences and they are the only methods by which patients with total AP resection can be fully evaluated. The overall accuracy of CT scan and MR imaging for detecting recurrent colorectal tumors ranges from 90% to 95%. Following AP resection, CT scan cannot reliably determine whether a soft tissue density in the surgical bed represents recurrent tumor, and it is important to obtain CT scan baseline studies 4 months after surgery and to repeat this examination at 6-month intervals. Scar tissue, even if initially masslike, shrinks over time and after 1 year should be smaller and its margins more sharply defined. Any apparent increase in size of a mass or any demonstration of adenopathy must be considered an indication for biopsy. Recurrent tumors that do not extend to the pelvis or abdominal sidewalls or invade bone or nerves can be resected. Subtle tumor recurrence or tumor foci in small nodes can be detected by PET scan and immunoscintigraphy, but their future role in the diagnostic imaging of colorectal cancer patients depends on the results of ongoing studies. Helical CT scan has the advantages of fast volume scanning associated with optimal bolus delivery, absence of artifacts related to motion, absence of missed slices, and availability of reformations in multiple planes and three-dimensional reconstruction (virtual reality). The role of this technique in patients with colorectal neoplasms has not been defined. Coronal reformations based on volume imaging can assist in deciding whether a patient with rectal cancer should undergo AP resection or a sphincter-saving procedure. MR imaging with endorectal coil can also provide this information. The rapid scanning and acquisition of an imaging volume opens new doors for staging of colorectal tumors, and it is likely that many new applications including three-dimensional reconstructions of the tumor will be of benefit to patients. Three-dimensional reconstruction of the colon with virtual reality is less-invasive than colonoscopy, but at present is very time-consuming and not cost-effective.

Cost-effectiveness of PET imaging in clinical oncology

To be cost-effective, PET must be diagnostically accurate and effective in improving management without increasing treatment cost. To evaluate diagnostic accuracy, we performed prospective evaluations of whole-body PET imaging in staging of non-small-cell lung cancer (99 patients), detection of recurrent colorectal cancer (57 patients), diagnosis of metastatic melanoma (36 patients), and staging of advanced head and neck cancer (29 patients). In each case, PET was more accurate than anatomic imaging for determination of the presence and extent of tumor and demonstration of nonresectable disease. PET was also more accurate than conventional imaging in staging Hodgkin's disease (30 patients). We evaluated the management impact of PET retrospectively, by reviewing the treatment records of 72 patients with solitary pulmonary nodules or non-small-cell lung cancer, 68 patients with known or suspected recurrent colorectal cancer, 45 patients with known or suspected metastatic melanoma, and 29 patients with advanced head and neck tumors. PET improved patient management by avoiding surgery for nonresectable tumor and for CT abnormalities that proved to be benign by PET imaging. For determining cost impact, the costs of surgical procedures were determined from Medicare reimbursement rates, and the cost of a PET study was taken to be $1800. The savings from contraindicated surgical procedures exceeded the cost of PET imaging by ratios of 2:1 to 4:1, depending on the indication. PET was decisively more accurate and cost-effective than anatomic imaging by CT, combining improved patient care with reduced cost of management.

Five-Year Follow-up After Radical Surgery for Colorectal Cancer

To determine whether an intensified follow-up of patients with colorectal cancer can lead to improved reresectability and a better long-term survival. A prospective randomized trial of 106 patients. Oulu University Hospital, a referral center in northern Finland. A total of 106 consecutive patients who underwent radical resection for colorectal cancer, 54 of whom were randomized into a conventional follow-up group and 52 into an intensified follow-up group. After a 5-year follow-up, the time of detection of recurrence, the recurrence rates, the first method showing recurrence, the mode of recurrence, reresectability, and survival were compared between the groups. The recurrences were identified earlier in the intensified follow-up group than in the conventional follow-up group (mean +/- SD, 10 +/- 5 months vs 15 +/- 10 months). The overall recurrence rate was 41%, with 39% in the conventional group and 42% in the intensified group. Carcinoembryonic antigen determination was the most common method showing recurrence in both groups. Endoscopy and ultrasound were beneficial in the intensified follow-up group, but computed tomography failed to improve the diagnostics. The mode of recurrence did not differ between the groups. Radical resections were performed on 19% (8/43) of the patients, 14% (3/21) in the conventional group and 22% (5/22) in the intensified group. The cumulative 5-year survival was 54% in the conventional group and 59% in the intensified group. Earlier detection of recurrent colorectal cancer by intensified follow-up does not lead to either significantly increased reresectability or improved 5-year survival.

Usefulness of carcinoembryonic antigen monitoring despite normal preoperative values in node-positive colon cancer patients.

The aim of our study was to determine to what extent serial carcinoembryonic antigen (CEA) monitoring is helpful in detecting colorectal cancer recurrence in patients if their preoperative serum CEA is normal. Additional major objectives of this study were to correlate CEA immunohistochemical features of the primary tumor with serum CEA levels at the time of tumor recurrence in node-positive colorectal cancer patients with low preoperative CEA values. One hundred fourteen node-positive colorectal cancer patients with preoperative serum CEA levels of < 5.0 ng/ml undergoing clinically curative operations were studied. Primary tumors were evaluated for tissue CEA using the same monoclonal antibody as used for serum CEA determinations utilizing the avidin-biotin-peroxidase immunohistochemical technique. The exact preoperative serum CEA value did not correlate with tumor grade, immunohistochemical CEA intensity or pattern. In the 32 patients who developed recurrent cancer, the serum CEA at recurrence was greater than 5 ng/ml in 44 percent. All such patients had CEA present in their primary tumor. There was no correlation with the exact preoperative serum CEA, the intensity of the primary tissue CEA, or the localization of such CEA and subsequent serum elevation at recurrence. Serum CEA is a useful marker in the detection of recurrent colorectal cancer despite normal preoperative values.

Modelling of serial carcinoembryonic antigen changes in colorectal cancer.

Carcinoembryonic antigen (CEA) is a tumour marker mainly used for detection of recurrent colorectal cancer. CEA series in 295 patients, who had a macroscopic radical resection of a primary colorectal cancer were studied. A kinetic model was fitted to CEA series of individual patients. Applying the kinetic model recurrences were identified with a sensitivity of 70-80% and specificity of 80-90%. Simulations were performed in order to find the optimal sampling strategy for CEA during follow-up. Simulations showed that CEA determinations at a few weeks interval between would be optimal for early detection of recurrences.

THE CLINICOPATHOLOGICAL FEATURES OF COLORECTAL CANCERS WITH HIGH SERUM CONCENTRATION OF CEA, AND THE CLINICAL USEFULNESS OF POSTOPERATIVE CEA DETERMINATION FOR THE PREDICTION OF RECURRENT FOCI

We investigated the clinicopathological features of colorectal cancers with positive serum CEA level in resected cases, and clinical value of postoperative CEA measurement for the prediction of recurrent foci. Positive CEA was defined as the serum concentration of more than 2.6 ng/ml. Of all colorectal cancer cases during the investigation period, 47% of them showed positive serum CEA level preoperatively. The incidence of preoperative serum CEA showed significant correlations with clinicopathological features such as a degree of venous invasion, hepatic metastasis and depth of invasion. However, histological type, maximum diameter of the tumor, lymphatic invasion or lymphnode metastasis showed no correlation with preoperative CEA level. Among the patients with positive preoperative CEA level followed by curative resection, 91% showed negative CEA level one or two months after operation. On the contrary, when the resection was non-curative one, only 25% of positive preoperative CEA turned to negative following the operation. In the light of this fact it was suggested that if positive CEA level didn't return to normal postoperatively, a possible presence of residual cancer lesion may be suspected. In 88% of patients with recurrence positive CEA level was noted. There was little difference in this incidence whether or not the preoperative CEA level showed positive. Most cases with recurrent foci showed the elevation in CEA prior to the appearance of clinical manifestations. Therefore it is concluded that postoperative CEA monitoring is considered to be very useful for the early detection of colorectal cancer recurrence.

The role of CEA, TPA and CA 19-9 in the early detection of recurrent colorectal cancer.

Eighty-eight consecutive patients who underwent curative resection for colorectal cancer between 1983 and 1985 were studied prospectively to evaluate the roles of sequential CEA, TPA and CA 19-9 determinations and independent clinical examination in the early diagnosis of resectable recurrences. Twenty nine recurrences were detected between 8 and 38 months after primary surgery. CEA, TPA and CA 19-9 showed a sensitivity of 72%, 62% and 38%, and a specificity of 78%, 86% and 97%, respectively. Of eight recurrences in which CEA was not raised, five induced a rise in TPA and two a rise in CA 19-9. The rise in the serum concentration of one of the three markers was the first sign of relapse in 23 (79%) patients. Two second-look laparotomies based solely on a rise in serum markers were performed. In one case diffuse recurrent disease was found, and in the other a resectable solitary hepatic metastasis was found.

Does immunoscintigraphy improve early diagnosis of metastatic or recurrent cancer?

In 42 patients with suspicion of recurrent colorectal cancer results of conventional diagnostic methods were compared to those of immunoscintigraphy. In 69% of all cases the intraoperative findings of a second-look operation served for validation, in 31% the follow-up was controlled. Localization of recurrent tumors was successful in 83% using conventional methods versus 57% by immunoscintigraphy. This procedure disappointed especially by a low sensitivity (23%) and low predictive parameters (pos.: 33%; neg.: 37%) in regard to diagnosis of extrahepatic tumors compared to results of conventional methods (77%), 94% respectively 79%). The quote of false positive results was surprisingly high in immunoscintigraphy (n = 12), 83% of these especially in localization of extrahepatic tumors. Therefore, the validity of immunoscintigraphy as an additive diagnostic tool for early detection of recurrent colorectal cancer must be regarded critically.

A retrospective study of serial CEA determinations in the early detection of recurrent colorectal cancer.

In the past five years, routine CEA determinations have been carried out on all patients after curative operation for colorectal carcinoma. These patients also underwent a clinical follow-up examination in the Oncology Outpatient Department. In 86 patients, recurrence of a tumor was confirmed. In 31 cases, a second-look operation was carried out. The CEA determinations were retrospectively analyzed in these patients and correlated with the time the recurrence of the tumor was diagnosed. These results show that of 86 patients only 15 (17.4 per cent) had pathologic CEA values before clinical symptoms of tumor recurrence. In the patient group with local recurrence, only 11 (23.9 per cent) of 46 patients had previously pathologically raised CEA values. Of 31 patients, 15 (48.4 per cent) underwent curative resection after the second-look operation. At this time, 12 patients (38.7 per cnt) still had normal CEA values, whereas only three patients (9.7 per cent) had pathologically raised CEA values. From these results, it was established that early diagnosis of tumor recurrence was very low. Therefore, one should not rely more on postoperative routine CEA determinations in the postoperative monitoring of patients following curative operations for colorectal carcinoma than on regular comprehensive follow-up examinations of these patients.

Assessment of serial carcinoembryonic antigen (CEA) assays in postoperative detection of recurrent colorectal cancer.

Monthly serial postoperative CEA determinations, three-monthly system review plus physical examination, and a battery of six-monthly laboratory and radiologic tests were compared in order to evaluate each in detection of recurrent colorectal cancer. Twelve of the 33 patients studied prospectively developed recurrent disease. In this study CEA was found not to be a substitute for careful clinical follow-up, but if used in a serial manner it was a useful adjunct for detection of early recurrent cancer, especially intra-hepatic and retroperitoneal disease recurring in patients with elevated pretreatment CEA levels. The other laboratory and radiologic tests employed were often useful to confirm progressing disease, but they did not reveal any first evidence of recurrent disease.