Recurrent Colorectal Carcinoma Research Articles

84. Comparison of 18F-FDG PET to CT scan in the detection of recurrent colorectal carcinoma - an ROC analysis

s: Abstracts of the 30th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine

4572 The clinical impact of endoscopic ultrasound guided fine needle aspiration in the management of colorectal carcinoma.

Background/Aim: Endoscopic ultrasound (EUS) has become a well established tool in local staging of colorectal carcinoma (CRC). It provides high resolution imaging of the gastrointestinal wall and the surrounding tissue. The T (tumor) stage accuracy being 75-91% and the N (nodal) stage accuracy being 70-86% with the radial echoendoscope. There is scant data looking at the role of EUS guided fine needle aspiration (FNA) in CRC. Our aim was to determine whether EUS guided FNA had any impact on the management of CRC in terms of surgical management, neoadjuvant, and adjuvant treatments. Methods: The records of 46 consecutive patients diagnosed with CRC (2/98-11/99) referred to our department for EUS staging were reviewed. Initially, a radial echoendoscope was passed to the site of lesion. The patients were endosonographically staged, including involvement of the Internal Anal Sphincter (IAS), and, if suspicious lesions were noted, an EUS guided FNA was performed using the CLA-E. Samples were examined by a cyto-pathologist present during the procedure. The surgical pathology and subsequent treatment were noted. Results: Twelve (26%) out of the 46 patients had EUS guided FNA using the curvi-linear array echoendoscope (CLA-E). In eight (67%) of the cases, suspicious lymph nodes were sampled and in the remaining four (33%), areas suspicious for recurrence by CT scan or endoscopy, with negative biopsy, underwent FNA. Nine (75%) of the 12 FNA's were positive for detection of malignant cells. All cases of recurrent CRC were correctly diagnosed by FNA. There were five (63%) patients with positive lymph nodes. Four (80%) of the five patients went for pre-operative neo-adjuvant therapy based on these results and one patient went for postoperative treatment. There were three (37%) patients with negative lymph nodes. Two of these patients underwent preoperative neo-adjuvant therapy and one went straight for surgery. No complications were associated with intubation with the CLA-E or the FNA. Maximum depth achieved with CLA-E was 40cm. Conclusion: EUS guided FNA changed the management in a total of 75% of the patients biopsied by CLA-E by selecting patients into a surgical or upfront chemo-radiation treatment branch. In addition, EUS guided FNA accurately diagnosed recurrence of CRC in 100% of the patients. In summary, EUS guided FNA with the CLA-E has an important role in staging of CRC and predicting reccurrence of disease.

結腸・直腸癌再発の診断におけるFDG-PETの有用性と医療経済効果

結腸・直腸癌再発の診断におけるFDG-PETの有用性と医療経済効果

Intraoperative electron beam radiotherapy in recurrent colorectal carcinoma.

The installation of a dedicated linear accelerator in a shielded operating room in 1992 allowed us to start a feasibility study of intraoperative electron beam radiation therapy (IOERT) in colorectal carcinoma. From March 1992 to February 1996, 28 patients with recurrent colorectal carcinoma were treated with maximal surgical resection and IOERT to the pelvis (n = 20) or paraortics (n = 8). IOERT dose ranged from 10 to 20 Gy with electron energies of 6-15 MeV. Postoperative external beam radiation therapy (EBRT) of 45-50 Gy was planned for the previously unirradiated patients. IOERT was well tolerated, but 10 (70%) of 13 patients in the previously unirradiated group did not complete the EBRT per protocol. Eight patients (29%) had some morbidity including surgically related fistula distal from IOERT sites. Two patients developed pelvic pain, which can be attributed to IOERT. Three-year local control at sites treated with IOERT was 40% (53% for previously irradiated patients and 27% for previously unirradiated patients). The 3-year actuarial overall survival was 12% (17% for previously irradiated patients and 8% for previously unirradiated patients). Our initial experience showed that it was feasible to treat poor prognostic colorectal cancer patients with IOERT. The morbidity observed was mainly related to extensive surgery in high-risk patients. Poor local control was obtained in patients treated with low-dose IOERT alone. Hence, previously unirradiated patients are encouraged to complete the planned EBRT or, alternatively, are considered for EBRT preoperatively or are given a higher IOERT dose (up to 20 Gy) if EBRT will not be given. Since IORT doses >20 Gy are associated with nerve toxicity, we currently add limited dose EBRT in the previously irradiated group. Patients with disease located in multiple abdominal sites are no longer considered candidates for IOERT.

Intraoperative electron beam radiotherapy in recurrent colorectal carcinoma

Background and Objectives The installation of a dedicated linear accelerator in a shielded operating room in 1992 allowed us to start a feasibility study of intraoperative electron beam radiation therapy (IOERT) in colorectal carcinoma. Methods From March 1992 to February 1996, 28 patients with recurrent colorectal carcinoma were treated with maximal surgical resection and IOERT to the pelvis (n = 20) or paraortics (n = 8). IOERT dose ranged from 10 to 20 Gy with electron energies of 6–15 MeV. Postoperative external beam radiation therapy (EBRT) of 45–50 Gy was planned for the previously unirradiated patients. Results IOERT was well tolerated, but 10 (70%) of 13 patients in the previously unirradiated group did not complete the EBRT per protocol. Eight patients (29%) had some morbidity including surgically related fistula distal from IOERT sites. Two patients developed pelvic pain, which can be attributed to IOERT. Three-year local control at sites treated with IOERT was 40% (53% for previously irradiated patients and 27% for previously unirradiated patients). The 3-year actuarial overall survival was 12% (17% for previously irradiated patients and 8% for previously unirradiated patients). Conclusions Our initial experience showed that it was feasible to treat poor prognostic colorectal cancer patients with IOERT. The morbidity observed was mainly related to extensive surgery in high-risk patients. Poor local control was obtained in patients treated with low-dose IOERT alone. Hence, previously unirradiated patients are encouraged to complete the planned EBRT or, alternatively, are considered for EBRT preoperatively or are given a higher IOERT dose (up to 20 Gy) if EBRT will not be given. Since IORT doses >20 Gy are associated with nerve toxicity, we currently add limited dose EBRT in the previously irradiated group. Patients with disease located in multiple abdominal sites are no longer considered candidates for IOERT. J. Surg. Oncol. 1999;72:66–71. © 1999 Wiley-Liss, Inc.

Phase II study of first-line LY231514 (multi-targeted antifolate) in patients with locally advanced or metastatic colorectal cancer: An NCIC Clinical Trials Group study

Metastatic colon cancer is difficult to treat with treatment being palliative and with little effect on survival. This trial has evaluated the effects of LY231514 (Multitargeted antifolate (MTA)) given to previously untreated patients with recurrent or metastatic colorectal carcinoma. All patients were required to have a histological diagnosis of colorectal adenocarcinoma with measurable disease and no prior chemotherapy for metastatic disease. Patients had to have had performance status of 0-2, pretreatment absolute granulocyte count of > or = 1.5 x 10(9)/l and a platelet count of > or = 150 x 10(9)l. Patients received MTA at a dose of 600 mg/m2 by 10 minute infusion on day 1 repeated every 21 days. After the first 9 patients, this dose was reduced down to 500 mg/m2 every 21 days because of toxicity. Doses of MTA were modified depending on nadir counts. Thirty-two eligible patients were enrolled and twenty-nine were evaluable for response. Three patients did not have repeat radiological testing to determine response because they went off study after only one cycle of treatment due to toxicity. In the 29 evaluable patients, there was 1 complete response, 4 partial responses and 14 patients with stable disease. Response rate was 17.2% (95% confidence intervals: 5.8%-35.8%). All responses occurred in the patients receiving a starting dose of MTA 500 mg/m2. Median time to progression for all eligible patients was 3.3 months. The most common toxicities experienced were mild to moderate fever, lethargy, anorexia, nausea, vomiting, stomatitis, abdominal pain, diarrhea, and skin rash. There was one death due to sepsis. Single-agent MTA at 500 mg/m2 given every three weeks has modest activity in metastatic colorectal carcinoma.

Radioimmunoguided surgery for recurrent colorectal cancer manifested by isolated CEA elevation

BACKGROUND Carcinoembryonic antigen (CEA) is a sensitive marker for detecting recurrent colorectal carcinoma. An asymptomatic rise of CEA can precede by several months the detection of recurrent cancer by standard imaging modalities. Yet, surgeons are hesitant to operate solely on the basis of an observed increase in CEA. We investigated the ability of radioimmunoguided surgery to enhance the surgeon's capability of detecting intraabdominal disease in these patients. METHODS Nineteen patients who underwent radioimmunoguided surgery for suspected tumor recurrence based solely on elevated CEA were included in the study. They underwent colonoscopy and CT of the abdomen and chest, all of which were negative. They then underwent scintigraphy scan with an anti-CEA monoclonal antibody (MoAb) labeled with 99mTc or Indium I-111. All patients were injected with the CC49 MoAb (an anti-TAG-72 tumor-associated glycoprotein) labeled with 125I three weeks before surgery. During surgery, traditional exploration was followed by survey with a gamma-detecting probe. RESULTS Traditional surgical exploration identified 26 recurrent tumors: 7 hepatic, 8 pelvic, 6 retroperitoneal, 3 colonic, 1 splenic, and 1 anastomotic. Radioimmunoguided surgical exploration confirmed all recurrent tumors and identified additional tumor sites in seven patients that resulted in changing the surgical plan. CEA scans correlated with intraabdominal findings in seven patients. Abdominal pathology did not correlate completely with the scans in three patients, and CEA scan results were undetermined in two patients. CONCLUSION Patients with elevated CEA and no other findings should be operated upon without delay, and radioimmunoguided surgery should be used to enhance the surgeon's knowledge of the extent of disease. Cancer 2000;89:1692–8. © 2000 American Cancer Society.

A new thermo-expandable shape-memory nickel-titanium alloy stent for the management of ureteric strictures.

To assess the ease on insertion, patient tolerance, undesirable side-effects, degree of encrustation and duration of upper tract decompression with a new thermo-expandable shape memory alloy ureteric stent. From November 1996 to October 1998, 15 patients with ureteric strictures were treated with a new nickel-titanium shape-memory alloy stent, the Memokath 051 (Engineers & Doctors A/S, Hornbaek, Denmark). A total of 22 insertions were carried out. Ureteric obstruction was caused by recurrent colorectal carcinoma in four patients; two patients each with transitional cell carcinoma of the bladder, iatrogenic injury or ischaemia at the uretero-ileal anastomosis; and one patient each with metastatic lymph nodes from prostatic carcinoma, radiation-induced fibrosis, pelvi-ureteric junction obstruction, metastatic carcinoma of the vagina and extra-luminal endometriosis. The stent has a shaft diameter of 9 F and its proximal end expands to 17 F. The first three patients were treated with the original version, which expanded to 14 F. The unexpanded stent is inserted into the ureter after initial dilatation of the stricture to 12 F. The stent is expanded by injection with sterile water preheated to 50 degrees C. The procedures were carried out under a general anaesthetic and patients were allowed home the next day. The follow-up protocol included initial intravenous urography (IVU) at 6 weeks, with assessment of a mid-stream urine sample and renal function tests. These were repeated at 3-monthly intervals. Isotopic renography was performed when indicated. The mean (range) follow-up was 10.6 (2-21) months; there was complete relief of upper tract obstruction in all patients. No stent-related symptoms, e.g. pain, sepsis, haematuria or frequency, were noted and no encrustation has occurred so far. The stent migrated in the first three patients with the original smaller diameter of stent but decompression of the upper tracts was maintained. None of the modified wider stents have migrated. The return of peristalsis in the proximal ureter was detected during IVU. There was no apparent endothelial growth through the stent material and no re-admissions for stent-related complications. Early experience with this new stent is very encouraging. All patients have maintained satisfactory decompression of their upper tracts with no need for repeated hospitalization for stent changes. There have been no untoward side-effects so far. This stent appears to have a valuable place in the long-term management of ureteric strictures; it is probably most suited for malignant ureteric obstruction. It should be considered in the management of selected benign strictures that require long-term JJ stenting.

Carcinoembryonic antigen: its value in the follow-up of patients with colorectal cancer.

We examined the value of carcinoembryonic antigen (CEA) monitoring for detecting treatable recurrence of colorectal carcinoma. CEA assays were undertaken in 193 patients over a 2-year period. The levels in 34 patients were raised in one or more assays above the laboratory-defined upper limit of normal; 31 cases were reviewed retrospectively. In 10% of patients there were Dukes' A lesions at the initial resection, in 39% Dukes' B, and in 52% Dukes' C1 or C2. Tumours were rectal in 61%. Median follow-up was 3 years (range, 16 years-2 months). In 23 of 31 (74%) there were symptoms or signs of recurrent disease prior to or simultaneously with an observed rise in CEA; in 8 the CEA rise preceded the onset of symptoms or the appearance of signs. Of the 31 cases 26 underwent investigation for recurrent disease, but in only 6 of these was the investigation driven by the observed rise in CEA rather than the onset of symptoms or presence of signs. Three of these six were false-positive results (50%), one has been lost to follow-up, and two had confirmed recurrence. Neither of the two with recurrence had operable disease. One of the two had no further treatment, and one underwent laparotomy at which multiple peritoneal seedlings were found. In both of the two cases going to laparotomy, one of which was prompted by a high CEA, widely disseminated disease was found. Over a 2-year period, serial CEA measurement thus yielded no patient benefit.

Impact of Radioimmunoscintigraphy on the Management of Colorectal and Ovarian Cancer Patients: A Retrospective Study

Noninvasive differentiation of benign from malignant disease has emerged as an important diagnostic challenge in the current age of health-care cost containment. Most physicians today acknowledge that early and accurate detection of cancer is important in successful treatment. Antibodies have been developed, labeled with radioactive isotopes, and used to detect and treat malignant tumors. During the past few years, several radiolabeled antibodies have received approval from the U.S. Food and Drug Administration for imaging colorectal, lung, ovarian, and prostate carcinomas, thus expanding and improving the physician's ability to detect and follow cancer in patients. At present, there is ample evidence in the literature to suggest that imaging with the IIIIn-labeled monoclonal antibody B72.3 is clinically useful for detecting primary/recurrent colorectal and recurrent ovarian carcinomas. In this article, we present a retrospective review of 136 patients from 10 moderate-sized hospitals who underwent a study with radioimmunoscintigraphy (R1S), using the IIIIn B72.3 antibody and standard diagnostic examinations for the detection of recurrent colorectal or ovarian carcinoma. The resulting data were analyzed in an effort to determine if (and how) information obtained from this radioimmunoscinti-graphic procedure is being used by referring physicians. Our findings suggest a gradually increasing use of scan findings with the IIIIn B72.3 antibody in making patient-management decisions.

Intraoperative high dose rate brachytherapy in recurrent or metastatic colorectal carcinoma.

The survival of patients with recurrent or metastatic colorectal cancer usually is less than 12 months. In an attempt to improve this dismal prognosis, we investigated the role of intraoperative high dose rate brachytherapy (IOHDR) in the management of these patients. From April 1992 to December 1996, 26 patients with locally recurrent or metastatic colorectal carcinoma were treated with maximal surgical resection and IOHDR. Intraoperative radiation dose ranged from 10 to 20 Gy, prescribed at 0.5 cm depth. The residual tumor irradiated was microscopic in 16 patients (62%) and gross residual in 10 patients (38%). Six patients received postoperative external beam radiation therapy. After a median follow-up of 28 months (range 6 to 54 months), seven of 15 evaluable patients (47%) failed in the area treated with IOHDR. The median time to local failure was 21 months (range 4 to 52 months). The median survival was 23 months (microscopic 24 months; gross 17 months), with a 4-year actuarial survival rate of 36%. Major morbidity was observed in 7 patients (47%) and usually was surgery-related. The use of IOHDR in association with radical resection increases local control in patients with recurrent or metastatic colorectal cancer. Patients with microscopic residual disease achieved a better result than do those with gross residual disease. Future strategies include the addition of limited EBRT dose to IOHDR, even for previously irradiated patients.

Use of carcinoembryonic antigen radioimmunodetection and computed tomography for predicting the resectability of recurrent colorectal cancer.

The objective was to determine the role of arcitumomab (CEA-Scan; Immunomedics, Morris Plains, NJ), an anticarcinoembryonic antigen (CEA) Fab' labeled with technetium-99m, in the presurgical evaluation of patients with recurrent or metastatic colorectal carcinoma. Surgical resection is the only method known to cure recurrent or metastatic colorectal carcinoma. The location and extent of disease must be determined before surgery. The role of antibody imaging, a new cancer detection modality, in preoperative evaluation for resection of locally recurrent or metastatic colorectal cancer has not been established, either alone or in combination with standard diagnostic modalities. In a blinded analysis of 209 patients with known or suspected colorectal cancer, the accuracy of arcitumomab, alone and combined with computed tomography (CT), was compared to that of CT for predicting abdominopelvic tumor resectability by correlating the results with surgical and histopathologic findings. Arcitumomab alone or combined with CT was found to be significantly more accurate for predicting surgical outcome than CT alone. When the results of CT and arcitumomab were concordant for abdominopelvic resectability, nonresectability, or absence of disease, the prediction was accurate in 67%, 100%, and 64%, respectively. Thus, the concordance for nonresectability (100% correct) may obviate the need for other diagnostic modalities or exploratory surgery. When the two tests were discordant, arcitumomab was correct substantially more often than CT. Because the liver is the most common site of distant metastasis in colorectal cancer, a subset of patients with hepatic disease was also analyzed; findings were similar to the overall resectability results. The product's safety profile was excellent: the incidence of induction of an immune response against arcitumomab was <1% and that of potentially adverse events was 1.2%. The accuracy of arcitumomab for assessing resectability status is greater than that of CT, both in all patients undergoing evaluation for curative abdominopelvic resection of colorectal cancer and in the subset of patients with suspected or proven liver metastases. The additional use of arcitumomab with CT potentially doubles the number of patients who could be saved the cost, morbidity, and mortality of unnecessary abdominopelvic surgery and increases those who are potentially resectable for cure by 40%.

THE APPROACH TO THE PATIENT WITH SINGLE AND MULTIPLE LIVER METASTASES, PULMONARY METASTASES, AND INTRA-ABDOMINAL METASTASES FROM COLORECTAL CARCINOMA

Recurrent colorectal carcinoma constitutes a major health care problem, with 90,000 patients diagnosed annually with metastatic disease. Recent advances have offered treatment to selected patients with liver, lung, and intra-abdominal metastases. Resection of liver secondary tumors improves 5-year survival from 0% to approximately 30% and offers the only possibility for cure. As experience mounts, hepatic surgery can be performed with quite acceptable morbidity and mortality. Adjuvant therapies are being developed that may improve results with surgery alone. Cryoablation is a new technique that appears to effectively eradicate liver tumors, but its role remains to be defined. In patients with unresectable disease, the benefit of hepatic artery infusion of chemotherapy is unproven. Resection of pulmonary metastases significantly improves survival in patients with solitary nodules. Consistent data regarding the benefit of pulmonary metastatectomy in patients with multiple nodules are not available. Combined cytoreductive surgery and intraperitoneal hyperthermic chemotherapy is being investigated as a treatment for peritoneal carcinomatosis from colorectal cancer. Although selected patients may benefit, this combined treatment modality appears to be less effective in patients with colorectal cancer than with other types of cancer.

Local recurrence of rectal cancer: evaluation with F-18 fluorodeoxyglucose PET imaging.

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) is a useful technique for detection of malignancy. The purpose of this study was to determine if FDG-PET scanning using visual and quantitative analyses can identify patients with recurrent colorectal tumor following abdominoperineal resection. Eighteen patients were evaluated for possible local recurrence of rectal carcinoma following abdominoperineal resection. The clinical presentation included rising carcinoembryonic antigen levels (n = 5), increasing size of a presacral mass on computed tomography or magnetic resonance (n = 13), or local symptoms (n = 3). Axial PET images of the pelvis were obtained following an injection of 10 mCi of FDG prior to biopsy. Quantitative analysis was performed by calculation of a standardized uptake ratio (SUR), and the images were interpreted by two radiologists in consensus. FDG-PET findings were correlated with histological or cytological findings and with the clinical outcome. Recurrent malignancy was confirmed in 13 patients by surgery (n = 8) or percutaneous biopsy (n = 5). Benign lesions were confirmed in five patients by surgery (n = 1), biopsy (n = 3), or clinical follow up (n = 1). Visual analysis of the FDG-PET data had a sensitivity of 92.3% (12/13) for recurrent disease (95% confidence limits; 63.9%, 99.8%) and a specificity of 80% (4/5; 95% confidence limits; 28.3%, 99.4%). SUR values were significantly higher in malignant lesions (range = 2.92-19.74, mean = 6.89) than in benign ones (range = 1.40-3.47, mean = 1.96; p = 0.002). FDG-PET is an accurate technique for detection of locally recurrent colorectal carcinoma. Visual analysis is equivalent to quantitative analysis for detection of disease.

Serum carcinoembryonic antigen concentration doubling time correlates with tumor biology and life expectancy in patients with recurrent gastrointestinal carcinoma.

To determine if carcinoembryonic antigen (CEA) concentration doubling time (DT) can predict the course of disease and characterize tumor biology. Retrospective case series of patients who exhibited a distinct increase in circulating CEA during disease recurrence in the routine postoperative follow-up. A tertiary general hospital. Twenty patients with recurrent gastric carcinoma and 17 patients with recurrent colorectal carcinoma. The CEA DT was determined from semilogarithmic plots of CEA concentration time courses. The quantitative analyses of the CEA DT as related to various host and tumor characteristics, modes of recurrence, and life expectancy. The mean CEA DTs for gastric and colorectal carcinomas were 229 days and 86 days, respectively. Although there were no significant differences with regard to patient age, tumor size, gross appearance, and histological differentiation, women had shorter CEA DT than did men. Flow cytometric analysis showed that tumors with a higher proportion of cells in S phase (> or = 15%) had significantly shorter CEA DT than those with a lower S-phase fraction (< 15%). There was a significant correlation between the CEA DT and the length of survival after the initial CEA concentration increase in patients with recurrent gastric and colorectal carcinomas. In the multiple regression analysis of patients who had been treated with curative surgery and chemotherapy, CEA DT proved to be a major independent prognostic factor. Carcinoembryonic antigen DT predicts life expectancy in patients with adenocarcinoma of the gastrointestinal tract. Differences in survival time are closely associated with variations in the biological aggressiveness of individual tumors.

Value of carcinoembryonic antigen monitoring in curative surgery for recurrent colorectal carcinoma.

This study is designed to review a carcinoembryonic antigen (CEA)-driven postoperative protocol designed to identify patients suitable for curative reresection when recurrent colorectal cancer is identified. A total of 285 patients who were operated on for colon or rectal carcinoma between 1981 and 1985 were evaluated (with CEA levels) every two months for the first two years, every three months for the third year, every six months for years 4 and 5, and annually thereafter. CEA levels above 5 microg were considered abnormal and were evaluated with diagnostic imaging and/or endoscopy. Follow-up was available for 280 patients (98.2 percent). Distribution of patients by Astler-Coller was: A, 14 percent; B1, 20 percent; B2, 39 percent; C1, 5 percent; C2, 21 percent. There were 62 of 280 patients (22 percent) who developed elevated CEA levels, with 44 patients who demonstrated clinical or radiographic evidence of recurrence. Eleven patients were selected for surgery with curative intent (4 hepatic resections, 1 pulmonary wedge resection, 2 abdominoperineal resections, 2 segmental bowel resections, and 2 cranial metastasectomies). Three of 11 patients (27 percent) benefited and have disease-free survivals greater than 60 months. Of the 223 patients without elevated CEA, 22 (9.9 percent) had recurrent cancer without any survivors. Overall, 3 of 285 patients (1.1 percent) were cured as a result of CEA follow-up. CEA-driven surgery is useful in selected patients and can produce long-term survivors.

Primary and recurrent colorectal cancer masquerading as gynaecological malignancy.

To make clinicians more aware of the phenomenon of primary and recurrent colorectal and anal carcinoma masquerading as primary gynaecological malignancy, we reviewed the records of 8 women referred to our gynaecological oncology unit with primary colorectal cancer (1), recurrent colorectal cancer (6) and primary anal cancer (1). Seven of these patients presented with abnormal vaginal bleeding or discharge. All patients had Papanicolaou smears performed; 7 were abnormal and 1 unsuitable for cytological assessment. None of the 6 patients with recurrent carcinoma had been previously treated with more than standard anterior or abdominoperineal resection; no radiotherapy had been given, and only 1 patient had received chemotherapy. These patients were treated in our gynaecological oncology unit for their recurrence by surgery and/or chemotherapy and/or irradiation. All 6 had further recurrences in the pelvis despite this aggressive therapy. Follow-up of colorectal cancer in women should involve gynaecological history, pelvirectal examination and Pap smear at each visit. Correct diagnosis of the colorectal origin of a genital tract tumour is made on careful history, examination and biopsy. An abnormal Pap smear may be the first indication of recurrent colorectal cancer in the cervix and vagina, although most patients ultimately present with abnormal vaginal bleeding. The presence of a tumour invading both cervix and posterior vaginal wall is suggestive of spread from a colorectal tumour compared to the more common lateral spread of a cervical primary.

Positron emission tomography to stage suspected metastatic colorectal carcinoma to the liver

Accurate detection of recurrent colorectal carcinoma remains a clinical challenge. Positron emission tomography (PET) using 18F-fluorodeoxyglucose (18FDG) is an imaging technique that allows direct evaluation of cellular metabolism. 18F-fluorodeoxyglucose PET was compared to computed tomography (CT) and CT portography for staging metastatic colorectal carcinoma. Twenty-four patients previously treated for colorectal carcinoma who had suspected recurrence to the liver underwent an 18FDG PET scan of the entire body. All patients had either a CT scan of the abdomen (n = 17), a CT portogram (n = 18), or both (n = 11). The final diagnosis was obtained by tissue pathology in 19 patients and clinical follow-up in 5 patients. A total of 60 suspicious lesions were identified. Of the 55 intrahepatic lesions, 39 were malignant and 16 were benign. Of the 5 extra-hepatic lesions, 4 were malignant. The 18FDG PET imaging had a higher accuracy (93%) than CT and CT portography (both 76%) in detecting metastatic disease to the liver, and detected unsuspected extrahepatic recurrence in 4 patients. Although the sensitivity of 18FDG PET (90%) was slightly lower than that of CT portography (97%), the specificity was much higher (100% versus 9%), including postsurgical sites. 18FDG PET altered surgical plans in 6 (25%) of 24 patients. 18FDG PET is extremely useful in staging patients with suspected metastatic colorectal carcinoma to the liver.

Indium-111 OncoScint CR/OV and F-18 FDG in colorectal and ovarian carcinoma recurrences. Early observations.

Indium-111 satumomab pendetide (In-111 OncoScint) planar and SPECT imaging and F-18 FDG positron emission tomography (PET) have been found individually to be helpful in the detection of recurrent colorectal and ovarian cancer, but have not been compared. Twelve patients who were examined for recurrent colorectal or ovarian carcinoma underwent both In-111 OncoScint imaging and F-18 FDG PET imaging. All had normal or equivocal results of CT or MR studies. Tumor detection abilities were similar in most cases. However, Oncoscint demonstrated an advantage in the detection of carcinomatosis. PET demonstrated an advantage in detecting focal tumor recurrence in one case and, not unexpectedly, in detecting liver metastases. All positive nuclear studies for tumor were found to be true-positives at pathology (7 patients), or by diagnostic new CT changes (1 patient). Finally, unreported, bone marrow, bowel, and colostomy sites appear to be normal sites of localization of F-18 FDG 1 hour after injection.

特集ＩＩ 大腸癌再発の予知とその対策 腫ようマーカーによる大腸癌再発の予知

大腸癌再発予知のために有用と考えられる各種腫瘍マーカーについて,知っておくべき基礎的知見と実際の使用上の注意について解説した.CEAとCA19-9の2種類は分化型腺癌で臨床的有用性が高く最も一般的な腫瘍マーカーであるが,肝炎,肝硬変,その他の良性疾患でも時に偽陽性となることがある.CEAの急激な上昇は肝転移によることが多く,逆に肺転移のみの場合はCEAの陽性率は低いので注意が必要である.CA19-9はLewis(a-,b-)の症例では一般に上昇しないと考えられ,そのような場合には他の腫瘍マーカーを用いるべきである.ST-439は癌における陽性率は前二者に比べて低いが,良性疾患での偽陽性率は低く特異性にすぐれている.Sialyl-Tnは粘液癌の再発の診断に有用である.CA125は腹膜転移の診断に有用であるが,良性の胸腹水貯留あるいは開腹術後等の場合に陽性となることがある.以上,個々の腫瘍マーカーの特性をわきまえ,適応に応じて選択することが重要である.