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Tumor cell DNA (ploidy) content was measured prospectively in samples from 320 patients resected for colorectal cancer with a minimum follow-up time of 2 years. All patients were followed and those with recurrence were investigated carefully. There was no correlation between tumors with an abnormal cellular DNA content (aneuploid or tetraploid) and patient age, sex, tumor site, pathologic stage, or histologic grade. In 236 patients who underwent potentially curative operations, 75 (32%) had local and/or distant recurrence. The recurrence rate was significantly higher (test statistic, 4.3; P = 0.04) for those patients with aneuploid tumors (52 of 142, 37%) compared with those with diploid tumors (23 of 94, 24%). The subgroups of patients where ploidy exerted an effect were in patients with Stage B tumors or mobile tumors and in patients over 65 years of age. Further analysis showed that there was a twofold increase in local recurrence and a threefold increase in distant recurrence in patients with aneuploid tumors, but no excess of patients who had both local and distant recurrence. Measurement of DNA ploidy can identify a group of patients undergoing curative surgery for colorectal cancer at high risk for recurrence. In combination with clinicopathologic factors, DNA ploidy may be useful in analyzing the results of trials and in planning adjuvant therapy.

We have investigated the influence of tumour cell DNA content (ploidy) on survival of 416 patients undergoing excisional surgery for colorectal cancer. Two hundred and eleven (51%) tumours had an abnormal DNA content (aneuploid or tetraploid). There was no correlation between ploidy status, sex, age and pathological stage, histological grade, tumour site, local tumour extension or assessment of curability. Patients with tumours with an abnormal DNA content had a poorer survival 68/211 (32%) than patients with near normal (diploid) DNA content 88/205 (43%) (test statistic 5.0, P = 0.02). The patient subgroups in which DNA content exerted an influence on survival were: stage B tumours (P = 0.0058), moderately differentiated tumours (P = 0.004), rectal tumours (P = 0.02), and mobile tumours (P = 0.02). Multivariant analysis showed that pathological stage, local tumour extension and DNA ploidy were all independent prognostic indicators whereas histological grade, tumour site and assessment of 'curability' were not. The influence of pathological stage, however, was much greater than that of local tumor extension or DNA ploidy. Tumour cell DNA content together with pathological stage and local tumour extension may be used in a prognostic index and may be important in planning adjuvant therapy.

Arteriography does not reliably distinguish between acute and chronic arterial occlusions. Seventeen patients with acute lower limb ischaemia were investigated by arteriography and by imaging with a platelet-specific monoclonal antibody (P256 Fab'); 20 MBq 111In-labelled P256 Fab' was administered intravenously and patients were imaged at intervals of between 20 min and 24 h. Thirteen patients were subsequently treated with intra-arterial thrombolysis. In six the images showed foci of increased uptake of 111In-labelled P256 Fab' and the corresponding arterial segment was recanalized. Patency to 30 days was maintained in four cases. Seven patients had negative scans, only four of whom achieved lysis, and two of these suffered early rethrombosis. The remaining four patients were excluded from thrombolysis by the arteriographic appearances. 111In-labelled P256 Fab' imaging can identify sites of acute arterial thrombosis and may have clinical applications in the management of peripheral vascular disease. Further studies are required to test whether the technique has a role to play in patient selection for thrombolysis.

Tumor cell DNA (ploidy) content was measured prospectively in samples from 320 patients resected for colorectal cancer with a minimum follow-up time of 2 years. All patients were followed and those with recurrence were investigated carefully. There was no correlation between tumors with an abnormal cellular DNA content (aneuploid or tetraploid) and patient age, sex, tumor site, pathologic stage, or histologic grade. In 236 patients who underwent potentially curative operations, 75 (32%) had local and/or distant recurrence. The recurrence rate was significantly higher (test statistic, 4.3; P = 0.04) for those patients with aneuploid tumors (52 of 142, 37%) compared with those with diploid tumors (23 of 94, 24%). The subgroups of patients where ploidy exerted an effect were in patients with Stage B tumors or mobile tumors and in patients over 65 years of age. Further analysis showed that there was a twofold increase in local recurrence and a threefold increase in distant recurrence in patients with aneuploid tumors, but no excess of patients who had both local and distant recurrence. Measurement of DNA ploidy can identify a group of patients undergoing curative surgery for colorectal cancer at high risk for recurrence. In combination with clinicopathologic factors, DNA ploidy may be useful in analyzing the results of trials and in planning adjuvant therapy.

Forty-one patients with advanced colorectal cancer were entered into a randomized controlled trial of treatment with proglumide--a gastrin receptor antagonist. There was no difference in survival between the treated and the untreated groups of patients, although there was a trend towards increased survival in those treated patients with hepatic metastases alone. Proglumide does not cause regression in advanced colorectal cancer but larger studies would be required to detect an effect on tumour growth.

The hepatic perfusion index (HPI) was measured in 180 patients with colorectal cancer: 109 with primary colorectal cancer, 38 with suspected recurrent colorectal cancer and 33 following curative resection of colorectal cancer. In 21 patients with proven metastatic disease serial imaging studies were performed. HPI was determined using the peak of the left kidney time-activity curve to define the division of arterial and portal blood flow. HPI was elevated (greater than 0.37) in 54 of 115 patients (47%) with no evidence of hepatic metastases, 17 of 27 patients (63%) with hepatic metastases at initial presentation and 21 of 25 (84%) with metastatic disease detected during follow-up. Only 4 of 13 patients (31%) with local recurrence but no evidence of liver metastases had an elevated HPI. Serial imaging of patients with metastatic liver disease demonstrated a rising HPI with clinical disease progression in 18 of 21 patients (86%). This study confirms the association of an elevated HPI with hepatic metastases and suggests that a rising HPI in serial studies is associated with progression of disease but highlights the deficiency of one single HPI estimation in the identification of patients with overt hepatic metastases.

The development of human antibodies recognising mouse immunoglobulins represents an obstacle to effective antibody therapy. This study shows that patients produce modest titres of antibodies (predominantly anti-mouse rather than anti-idiotypic) after a single low-dose injection for immunoscintigraphy, suggesting that repeated imaging with the same or a different antibody could be a problem. Fusion of the lymphocytes from a patient who had been imaged twice previously resulted in a monoclonal antibody that specifically binds to an IgG2b isotypic determinant. Anti-IgG2b antibodies predominated in this patient's serum. Production of human monoclonal antibodies from patients given mouse monoclonal antibodies not only allows a finer dissection of the immune repertoire but also provides possible reagents for controlling the human anti-(mouse Ig) response, for selection of class-switch variants of mouse monoclonal antibodies and enhancing tumour imaging.

Primary aortoenteric fistula is rare. The most common cause is atherosclerosis, followed by infection and carcinoma of the head of the pancreas. A case of spontaneous aortojejunal fistula due to recurrent colorectal cancer is reported.

A major problem in the chemotherapy of colorectal cancers is their resistance to most cytotoxic drugs which may be due to insufficient cellular transport. Drugs conjugated to monoclonal antibodies recognising tumour antigens may overcome these difficulties by providing access of active agents to the tumour cells. The anti-tumour monoclonal antibody shown to localise in patients with colorectal cancer, 791T/36, has been investigated as a potential targeting antibody. Eight cell lines were established from surgically resected material and were shown to bind 791T/36 antibody. They were screened for their sensitivity to methotrexate, 5-fluorouracil and daunomycin. Although 5-fluorouracil is the drug of choice for chemotherapy of colorectal cancer it was the most cytotoxic drug in only 2 of the 8 cell lines. Only the 4 cell lines which were resistant to methotrexate showed less cytotoxicity with methotrexate than 5-fluorouracil. The cell lines which were resistant to methotrexate were more sensitive to 791T/36-methotrexate conjugates. Daunomycin was the most cytotoxic drug in 4 of the 8 cell lines. However, a similar cytotoxicity was observed for free drug and 791T/36 daunomycin in the two lines tested. Selective monoclonal antibody drug conjugates may offer a solution to treatment of tumours which are resistant to classical chemotherapeutic agents. This is the first report to show that newly established cell lines that are resistant to classical chemotherapeutic agents are rendered sensitive when the drug enters the cell as a drug monoclonal antibody carrier.

The reliability of the technique for measuring the hepatic perfusion index (HPI) for the detection of liver metastases has been examined. Dynamic images from 173 patients with primary and recurrent colorectal cancer have been analysed by two operators using the peak values of both the right and left kidney time-activity curves. In 14.4% of analyses the right kidney HPI method failed, while only 5.7% of analyses failed using the left kidney method. The results showed (a) that disagreement between the operators HPI values was small but statistically significant (p less than 0.05) and (b) that disagreement between the two methods was highly significant (p less than 10(-7)), with the left kidney method resulting in a lower HPI value. An upper limit of normal for left kidney HPI of 0.37 was predicted from the data, assuming the corresponding right kidney value to be 0.40.

Murine monoclonal antibodies directed against tumour associated antigens are potentially useful in tumour diagnosis and therapy. However, all the antigens they recognise may be heterogeneously expressed on tumours and this may allow escape of cells from therapy if a single monoclonal antibody is used. One approach is to use combinations of monoclonal antibodies recognising complementary cell surface antigens. A flow cytometric method which allows accurate quantitation of the intensity of staining and the percentage of fresh primary tumour cells binding a series of monoclonal antibodies has therefore been developed. This allows calculations as the number of drug molecules which could be potentially delivered by each monoclonal antibody and the optimal combination of antibodies which should be used. Monoclonal antibodies recognising Y hapten (C14), CEA (228, 161) and 791T-p72 antigen (791T/36) have been screened as a possible combination for colorectal cancer. There was inter-tumour variation in the binding of all the monoclonal antibodies although combinations could reduce or abrogate this problem. A combination of the monoclonal antibodies C14, 228, 791T/36 and 161 would recognise 100% of tumours. Sixty per cent of tumours bound all four antibodies, 78% any three, 90% any two and 100% any one antibody. There was also intra-tumour variation in the number of tumour cells per lesion that were recognised, the best monoclonal antibody, 161, stained a mean of 59% of cells per tumour whereas the anti-cytokeratin monoclonal antibody stained a mean of 74% of cells per tumour. An increased intensity of staining of tumour membranes was observed when a combination of C14 and 228 was used compared to binding of individual antibodies. Furthermore there was still no significant binding to normal colon membranes. Combinations of monoclonal antibodies which recognise a high percentage of tumours are likely to be necessary for monoclonal antibody drug targeting to prevent tumour recurrence and/or metastases.

Non-steroidal anti-inflammatory drugs have been accused of causing false positive results in faecal occult blood tests for colorectal cancer. A study was therefore performed in 10,931 people undergoing faecal occult blood screening tests to assess the effect of these drugs on the predictive value of a positive test result. Those with a positive result were interviewed and a full drug history was taken before they underwent a full colorectal examination. Of the 455 people with a positive result, 50 were taking non-steroidal anti-inflammatory drugs: 10 (20%) had colonic neoplasia. Of the 405 who were not taking non-steroidal anti-inflammatory drugs, 129 (32%) had colonic neoplasia. These detection rates were not significantly different, and the predictive value of a positive result for an adenoma larger than 1 cm was 14% in the group not taking anti-inflammatory drugs and 26% in the group taking them (not significant). These results suggest that a finding of occult faecal blood cannot be attributed to upper gastrointestinal tract bleeding caused by non-steroidal anti-inflammatory drugs and should be followed by a thorough colorectal examination.

Over a 3-year period 164 patients undergoing arterial reconstruction for lower limb ischaemia had direct arterial pressure measurements during the operation. The arterial pressure was measured by direct puncture of the vessel with a No. 23 gauge needle connected, via a cannula, to a pressure transducer. The pressure was measured proximal and distal to anastomoses or endarterectomies, and note was made both of the absolute pressure and waveform. At 3 months 95 per cent were patent. In nine patients (5 per cent), there was a significant fall of pressure across the reconstructed artery and in eight of these procedures were carried out to correct the fault. The technique of direct arterial pressure measurement is quick and easy to perform, with equipment that is used routinely for monitoring by the anaesthetist. There has been no evidence of damage due to the arterial puncture itself. It provides a simple, objective assessment of adequacy of an arterial reconstruction and may lead to the early correction of otherwise unrecognized faults, and thus prevent early graft occlusion.

The monoclonal antibody (MAb) 791T/36 which has previously been shown to localise in colorectal cancer has been conjugated to methotrexate (MTX) for potential use as a chemotherapeutic agent in malignant disease. To examine its biodistribution and tumour localisation, 16 patients with primary colorectal cancer were injected intravenously with 131I-labelled 791T/36-MTX conjugate and imaged using a gamma camera after 48-72 hr. Serial blood samples were taken to determine the levels of circulating conjugate and samples of tumour and normal colon were assayed for uptake of radioactivity. Whole body biodistribution, visualised by gamma scintigraphy, and blood clearance of both the antibody and drug moieties of 791T/36-MTX were similar to that previously found with unconjugated antibody. Assays of tissue radioactivity showed positive tumour uptake of drug-antibody conjugate (T:NT greater than 1.9:1) in 13/15 primary tumour specimens (median T:NT = 2.9:1). These studies indicate that 791T/36-MTX conjugates may have potential in the treatment of metastatic colorectal carcinoma.

Imacis-1 is a combination of F (ab')2 antibody fragments, of two monoclonal antibodies, anti-CEA and 19.9, radiolabelled with Iodine-131. Thirteen patients with 14 tumours (eight pancreatic, six colorectal) were imaged to evaluate the ability of this radiopharmaceutical to detect both pancreatic and colorectal cancer. Positive tumour uptake was demonstrated by external gamma camera imaging in six patients with pancreatic cancer and in three with colorectal cancer. The results of this preliminary study confirm the ability of this antibody cocktail to localise in colorectal cancer and suggest that it may be of value in the detection of pancreatic cancer.

An asymptomatic population of 37,000 people in the Nottingham area were offered faecal occult blood tests in a screening study for colorectal cancer. Seventeen thousand nine hundred and thirty people completed the tests and 481 individuals with positive tests underwent full investigation of the colon. Eight people with previously undiagnosed inflammatory bowel disease were identified. In five cases there was total ulcerative colitis; in one a proctitis and in two Crohn's disease. Two further patients with ulcerative colitis were identified; they had been lost to follow up for 25 and 45 years respectively. The combined prevalence of inflammatory bowel disease was 56/10(5) and it is likely that current studies of the epidemiology of these conditions may underestimate the true prevalence by between 27% and 38%.

A flow cytometric technique has been established for accurately quantitating the cell surface density of MHC antigens and the percentage of cells expressing MHC antigens in 38 colorectal tumours. Thirty-four percent of tumours were partially or completely negative for HLA-ABC antigen expression. Although the quantity of HLA-ABC antigens varied widely, there was no correlation between the density of HLA-ABC antigens, or the percentage of cells expressing these antigens and clinicopathological stage. Fifty percent of the colorectal tumours expressed HLA-DR with varying antigen densities. All of the poorly differentiated tumours expressed HLA-DR but there was no correlation between expression of HLA-DR and clinicopathological stage. The aneuploid tumours expressed more HLA-ABC and HLA-DR antigens on a higher percentage of cells than the diploid tumours. Abnormal expression of the tumour associated antigens CEA, Y haptenic blood group and 791T p72 also correlated with expression of HLA-ABC and HLA-DR antigens on colorectal tumours. The majority of early derived in vitro dividing cells failed to express both HLA-ABC and HLA-DR antigens although they expressed high levels of tumour associated antigens. If there is a correlation between in vitro and in vivo growth perhaps tumours are maintained and seeded by MHC antigen negative cells.

Two hundred and nineteen patients underwent gastrectomy for cancer in Nottingham University Hospital between January 1978 and December 1985. Twenty of these patients had early gastric cancer (EGC). Barium meal was performed in 15 patients and upper gastrointestinal endoscopy in 15. In all cases, barium meal failed to define the early nature of this disease. Only two lesions were thought to be EGC endoscopically and at laparotomy three were considered to be EGC. As neither radiologist, endoscopist nor surgeon can reliably identify EGC, all patients with gastric cancer in the absence of proven metastases should undergo gastrectomy.