Colorectal cancer.
Explore the source record for details and available documents.
Colorectal Neoplasms↗
Biomedical subjects
R H Begent
Publications and source records attributed to R H Begent.
Gestational and nongestational trophoblastic tumors distinguished by DNA analysis.
In three patients in whom a diagnosis of gestational trophoblastic tumor was possible on the basis of pathology and elevated levels of serum human chorionic gonadotrophin, locus-specific minisatellite probes were used to identify restriction fragment length polymorphisms (RFLP) in DNA from the tumor, the patient, and her partner. On the basis of results from these studies, one tumor, originally diagnosed as a germ cell tumor, was reclassified as a gestational choriocarcinoma, whereas a second tumor, diagnosed as gestational choriocarcinoma, was shown to be of nongestational origin. In the third case, a diagnosis of gestational trophoblastic tumor was confirmed, but in this case the androgenetic origin of the tumor indicated that it was derived, not from the antecedent term pregnancy, but from a previous pregnancy with hydatidiform mole. This study clearly demonstrates the value of DNA analysis in the classification of tumors with trophoblastic differentiation.
Adult↗
Localization of CEA messenger RNA by in situ hybridization in normal colonic mucosa and colorectal adenocarcinomas.
Carcinoembryonic antigen (CEA) mRNA expression was studied in 14 cases of normal colorectal mucosa and colonic adenocarcinomas using in situ hybridization with a 32P-labelled cDNA probe to the unique 3'-untranslated region of CEA. This approach has the advantage that the target mRNA remains in the cell of origin, whereas there is considerable ambiguity in immunocytochemistry data for CEA because the protein is secreted. Furthermore, the specific cDNA probe overcomes potential problems of immunological cross-reactivity with other members of the CEA family. The results demonstrated that abundant, heterogeneously distributed CEA mRNA was present in colorectal adenocarcinomas, with the highest levels in cells lining glandular structures. Parallel immunohistochemistry with anti-CEA monoclonal antibody A5B7 showed that the regions of tumours with the highest levels of CEA mRNA also had the highest CEA protein levels, suggesting that the heterogeneous distribution reflects CEA expression rather than differential secretion of the protein. In the normal colonic mucosa, CEA mRNA expression was observed in surface epithelial cells and goblet cells of the upper crypts, with very low hybridization in the mid crypt and at the base. This crypt-surface distribution was identical to that observed for CEA protein. In situ hybridization therefore confirms that high levels of CEA mRNA are expressed in differentiated surface epithelial cells of the normal colon.
Adenocarcinoma↗
Factors influencing variability of localisation of antibodies to carcinoembryonic antigen (CEA) in patients with colorectal carcinoma--implications for radioimmunotherapy.
Tumour localisation of anti-tumour antibodies varies greatly between patients. Factors which may be responsible for this have been investigated in 56 patients with colorectal carcinoma with a view to improving radioimmunotherapy. Thirty-seven to seventy-four MBq of 125-I labelled mouse monoclonal antibody to CEA, was given intravenously and tumour resected 70-480 h later. Percentage injected activity kg-1 (% inj.act kg-1) in tumour, was inversely correlated with the time interval between injection and operation (P = 0.004). To assess the influence of other parameters on localisation, patients were divided into two time groups according to time interval between injection and operation, 70-120 h (n = 33) and 144-480 h (n = 23). In neither group was there a significant correlation of % inj.act kg-1 with time. The % inj.act kg-1 in tumour showed a significant correlation with that in the blood for both groups (P = 0.005 and P = 0.01). There was no significant correlation for either time group between % inj.act kg-1 in tumour and serum CEA values, the per cent of tumour cells positive for CEA and vascularity. Tumour to blood ratios varied considerably (range 0.3-28.5:1) suggesting that factors other than time and persistence of activity in the blood contribute to efficient targeting. Tumour to blood ratios were inversely correlated with % inj.act kg-1 in blood for the 70-120 h group (P = 0.007), and were positively correlated with % inj.act kg-1 in tumour (P = 0.012). Autoradiography showed that antibody localised predominantly on tumour cells but was distributed heterogeneously, was not solely related to the expression of antigen and in some cases accumulated in necrotic more than viable areas of tumour. Penetration of antibody into malignant acinar structures was poor and CEA-positive cells closer to the blood supply were targeted to a greater extent than distant cells. Preoperative administration of radiolabelled antibody to CEA may be helpful in selecting patients with favourable localisation for radioimmunotherapy.
Antibodies, Monoclonal↗
Doppler assessment of the uterine circulation and the clinical behaviour of gestational trophoblastic tumours requiring chemotherapy.
The haemodynamics of the uterine arteries and myometrium were assessed using Doppler ultrasound in forty consecutive patients requiring treatment for invasive mole and choriocarcinoma. The investigations were performed prior to the commencement of chemotherapy and the subjects followed prospectively. The Doppler waveforms from the uterine arteries were analysed using the pulsatility index. It was found that patients with a pulsatility index of 1.1 or less were significantly more likely to develop drug resistance than those with a higher value (P < 0.04). There was no significant association between the pulsatility index and metastatic disease or uterine bleeding. Five out of eight patients who developed drug resistance could have avoided initial inadequate treatment if the Doppler findings were included in the scoring system for selecting chemotherapy for these tumours. It can be concluded that assessment of the uterine arteries using the pulsatility index prior to the treatment of patients with invasive mole and choriocarcinoma is of help in predicting those who will develop drug resistance.
Arteries↗
Monoclonal antibody administration. Current clinical pharmacokinetic status and future trends.
Explore the source record for details and available documents.
Animals↗
Comparison of ondansetron and ondansetron plus dexamethasone as antiemetic prophylaxis during cisplatin-containing chemotherapy.
Ondansetron, a serotonin antagonist, is effective in controlling the emesis associated with cancer chemotherapy; however, emesis in patients receiving high-dose cisplatin is poorly controlled by ondansetron alone. Dexamethasone is an effective antiemetic with no known interaction with serotonin receptors and was thus chosen for study in combination with ondansetron. 31 patients (30 male, 1 female; median age 28.5 years, range 18-49) receiving a 4-day course of a chemotherapy regimen containing cisplatin (100-120 mg/m2) for metastatic germ-cell tumours were entered in a randomised, double-blind, cross-over trial comparing oral ondansetron plus placebo with oral ondansetron plus dexamethasone as antiemetic prophylaxis. Ondansetron (8 mg every 8 h) was given to all patients for 8 days from the start of chemotherapy. Patients were given 8 mg of dexamethasone or placebo every 8 h starting 2 h before cisplatin (on day 4) and continuing for six doses (ie, for 2 days only). A second course of chemotherapy began 14 days after the start of the first, during which patients crossed over to the alternative antiemetic regimen. Results were available from 27 patients. In the 24-48 h after cisplatin 78% of patients taking ondansetron plus dexamethasone reported complete or major control of emesis compared with 30% of those taking ondansetron plus placebo (p = 0.001). Cross-over analysis showed a significant advantage for ondansetron plus dexamethasone in the control of nausea (p = 0.013) and emesis (p less than 0.001) over the 8-day study. 24 of 26 patients expressed a preference for the combination therapy (p less than 0.001). Ondansetron plus dexamethasone is effective antiemetic prophylaxis for high-dose cisplatin chemotherapy, has few side effects, and is active when given orally.
Administration, Oral↗
A phase-I study of repeated therapy with radiolabelled antibody to carcinoembryonic antigen using intermittent or continuous administration of cyclosporin A to suppress the immune response.
The anti-mouse antibody response was examined in patients receiving repeated i.v. therapy with radiolabelled mouse monoclonal antibody (MAb) to carcinoembryonic antigen (CEA): 131I anti-CEA was given approximately every 2 weeks with cyclosporin A, to suppress the anti-mouse antibody response. Two schedules of cyclosporin A--intermittent therapy for 6 days with each course of anti-CEA and continuous therapy--were compared. Suppression of the immune response in the intermittent high-dose (3 patients) and continuous low-dose groups (4 patients) was equivalent, but the latter regimen was less toxic. Repeated therapy led to the formation of small amounts of anti-mouse antibody, but provided that cyclosporin A was continued it did not prevent further therapy or lead to an increase in the rate of clearance of anti-CEA from blood. Without cyclosporin A no more than 2 courses of antibody therapy could be given. Patients received up to 4 doses of 131I anti-CEA. The nadir platelet count was related to the half-life of 131I anti-CEA in blood. Thrombocytopenia limited the amount of 131I anti-CEA that could be given and determined the interval between treatments. Effective suppression of the anti-antibody response is possible and this study has determined that myelosuppression is the principal obstacle to repeated therapy with radiolabelled antibody.
Adult↗
The effect of radiosensitizers on radio-immunotherapy, using 131I-labelled anti-CEA antibodies in a human colonic xenograft model.
Anti-CEA antibodies were used for radio-immunotherapy in an established LS174T colonic xenograft in nude mice. A single IV dose of either 131I-PK4S (polyclonal) or -A5B7 (monoclonal) antibody produced tumour regression, and significantly delayed subsequent tumour growth. Administration of a clearing second antibody, 24 hr post 131I-PK4S and at 5 times the dose, significantly reduced the therapeutic effect of radio-antibody alone. Tumours of mice given non-specific antibody or unlabelled anti-CEA antibody grew like those of untreated controls. In an attempt to enhance therapy without increasing dose, radiosensitizers normally employed with external beam radiation were used in combination therapy. When the hypoxic cell radiosensitizer misonidazole was combined with 131I-A5B7, it significantly prolonged tumour-growth inhibition over radio-antibody alone. Conversely, the therapeutic effect of either radio-antibody was significantly reduced when used in combination with the halogenated pyrimidine radiosensitizer 5-iododeoxyuridine. Neither sensitizer alone affected tumour growth.
Animals↗
Cytoreductive surgery in disseminated non-seminomatous germ cell tumours of testis.
Between 1977 and 1988, 67 patients underwent surgical removal of residual metastatic deposits following an aggressive chemotherapy regimen (cisplatin, vincristine, methotrexate and bleomycin alternating with etoposide, actinomycin D and cyclophosphamide) for disseminated germ cell tumours of the testis (stage IIB or above). Ninety-one surgical procedures were performed. There were 63 (69 per cent) retroperitoneal lymph node dissections, 16 (18 per cent) thoracotomies, three (3 per cent) hepatic resections, three (3 per cent) craniotomies, five (5 per cent) delayed orchidectomies and one anterolateral decompression of the vertebral column. Nine (13 per cent) patients required a repeat retroperitoneal node dissection and one patient needed a repeat thoracotomy to remove recurrent metastatic deposits during the period of follow-up. Multivisceral resections and vascular reconstruction procedures were required in 20 (30 per cent) patients undergoing retroperitoneal node dissection. Fifty-five (82 per cent) patients remain in complete remission with a mean follow-up period of 49.6 months (range 2-121 months). Nine (13 per cent) patients died with metastatic disease between 2 months to 4 years after operation. There were three deaths in the perioperative period (4 per cent). The histology of the resected metastases revealed undifferentiated active tumour in 20 (30 per cent) patients, differentiated mature teratoma in 29 (43 per cent) patients and fibrosis/necrosis in 18 (27 per cent) patients. Twelve (60 per cent) patients with undifferentiated elements and 15 patients (60 per cent) with raised preoperative tumour markers (poor prognostic categories) are in complete remission. Cytoreductive surgery in patients with metastatic germ cell tumours offers the best chance of remission following chemotherapy even in poor prognostic group categories.
Adolescent↗
The value of radioimmunoguided surgery in first and second look laparotomy for colorectal cancer.
Radioimmunoguided surgery (RIGS) using an anti-CEA (A5B7) monoclonal antibody has been assessed in 52 patients (43 primary excisions and nine second look procedures) undergoing surgery for colorectal carcinoma. The antibody localized in 97.8 percent of primary tumours and in 88.8 percent of the principal tumor in second look procedures. Additional information concerning the extent of primary tumor was obtained in 11 of 43 patients (25.5 percent) undergoing excision of primary carcinoma and five of nine patients (55 percent) in the second look series. Incorrect information was obtained about the extent of the primary tumour in six patients (11.3 percent), whereas no incorrect information was obtained during second look procedures. RIGS correctly predicted the subsequent Dukes' staging in 77 percent of first look cases (sensitivity 65 percent, specificity 90 percent), although accurate identification of individual nodes was impossible. The technique influenced the surgical procedure performed in 2 of 43 cases (4.6 percent) in primary surgery and in three of nine patients undergoing second look laparotomy (33 percent). RIGS in primary colorectal carcinoma may provide additional information concerning extent of locally advanced tumors in particular and the principle that the subsequent surgery may be influenced has been established. The technique appears to have a greater role in second look procedures where it may help determine the extent of recurrent tumour. Larger follow-up series are required to define how the additional information provided by this technique may best be exploited.
Aged↗
Weekly etoposide, methotrexate and actinomycin D, alternating with cyclophosphamide plus vincristine (EMA/CO): a phase II study in advanced gastric carcinoma.
A total of 27 patients with measurable/evaluable metastatic or locally advanced gastric carcinoma were given combination chemotherapy comprising etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine (EMA/CO). Ten achieved partial remission, giving a response rate of 37% (95% CI; 21.7%-66.3%), 12 attained stable disease, whereas five had disease progression despite treatment. Drug toxicity was moderate to severe. Five of those who achieved partial remission underwent an attempt to resect residual disease which was successful in only three patients.
Adenocarcinoma↗
Optimum management of pineal germ cell tumours.
Non-seminomatous pineal region germ cell tumours have a poor prognosis when treated with radiation alone but little is known of the results of treatment with modern chemotherapy. Between 1983 and 1990 five pineal region germ cell tumours presented to the Charing Cross Hospital, London. All five patients received the EpPlt/OMB chemotherapy schedule with escalated dose systemic methotrexate and intra-CSF methotrexate. Two patients had had prior radiotherapy. Four patients (80%) remain well and disease-free 6 months--5 years after completing therapy. Chemotherapy is an effective modality for the treatment of pineal germ cell tumours and should be used when non-seminomatous elements are present or when the placement of ventriculo-peritoneal shunt in the presence of malignant cells in the CSF presents a risk of dissemination.
Adolescent↗
In vivo uptake of 131I-5-iodo-2-deoxyuridine by malignant tumours in man.
Explore the source record for details and available documents.
Administration, Oral↗
Histamine, leukotriene C4 and interleukin-2 increase antibody uptake into a human carcinoma xenograft model.
Systemically administered radiolabelled anti-tumour antibody is ineffective in treating the majority of patients with liver metastasis from colorectal carcinoma. We have assessed whether agents which increase capillary permeability can increase tumour uptake of antibody isotope conjugate. We developed a xenograft model of colorectal carcinoma using an antibody directed against carcinoembryonic antigen (CEA). Tumours were grown subcutaneously in the hind limbs of athymic rats to derive their circulation from the femoral artery. Cannulae were placed in the common iliac artery and iliolumbar vein. Antibody was delivered systemically, regionally and regionally with histamine, leukotriene C4 and interleukin-2. Regionally administered anti-CEA antibody resulted in a significantly greater (P = 0.004) tumour to normal tissue ratio (1.66, s.d. = 0.68) compared to systematically administered antibody (1.25, s.d. = 0.73). The addition of vasoactive drugs produced an approximately 3-fold increase with an increase to a mean tumour:liver ratio of 3.24 (s.d. = 1.39) for histamine (P less than 0.001 compared to systemic delivery), 3.21 (s.d. = 1.13, P less than 0.001) for leukotriene C4 and 3.80 (s.d. = 1.53, P less than 0.001) for interleukin-2. The addition of histamine significantly (P = 0.004) increased the mean tumour to liver ratio (1.73, s.d. = 0.44) of non-specific antibody uptake compared with either systemic (1.12, s.d. = 0.24) or regional delivery (1.25, s.d. = 0.54) of non-specific antibody alone. Increasing tumour capillary permeability can produce a significant clinically useful increase in tumour uptake of antibody-isotope conjugate.
Animals↗
Results with the EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine) regimen in high risk gestational trophoblastic tumours, 1979 to 1989.
OBJECTIVE: To assess the efficacy, toxicity and survival in patients with high risk GTT treated with the EMA/CO regimen (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine/oncovine). DESIGN: Open non-randomized study of 148 consecutive patients referred to the Charing Cross Hospital between 1979 and 1989. SETTING: Trophoblastic disease centre in a London teaching hospital. SUBJECTS: 148 consecutive patients with high risk GTT were treated with the EMA/CO regimen. 76 patients had received no prior chemotherapy and 72 had received prior chemotherapy. MAIN OUTCOME MEASURES: Survival, causes of treatment failure and toxicity were analysed. RESULTS: Of 76 patients who had received no prior chemotherapy, 62 (82%) are in remission; an overall survival of 85% for the 148 patients. Ten of the 76 patients without prior chemotherapy died from extensive disease within 3 weeks of starting chemotherapy. The complete and partial response rates to EMA/CO chemotherapy were 80% and 18% respectively. The addition of cisplatin salvaged 9 of 11 (82%) who developed drug resistance and did not require surgery. Salvage surgery alone resulted in 7 of 8 (87%) having complete remissions. Relapse after EMA/CO chemotherapy is uncommon (5.4%) but survival is still relatively good with further chemotherapy and/or surgery with 6 (75%) of 8 patients obtaining a further sustained remission. Complications from EMA/CO chemotherapy are acceptable with myelosuppression being dose-limiting. Late sequelae are uncommon: menstruation usually returns with a few months, and no fetal abnormalities have been recorded in subsequent pregnancies. One patient developed what we presume to be a therapy-induced acute myeloid leukaemia. CONCLUSION: At present EMA/CO chemotherapy is our treatment of choice for patients with high risk GTT. Its toxicity is predictable and reversible. In patients developing drug resistance, salvage surgery is important. Future developments may include further dose intensification with the addition of haemopoietic growth factors, earlier diagnosis and the separation of gestational from non-gestational trophoblastic tumours.
Adult↗
In situ and slot hybridization analysis of RNA in colorectal tumours and normal colon shows distinct distributions of mitochondrial sequences.
cDNA clones of mRNAs with an abnormal abundance in familial adenomatous polyposis were used to examine the levels and distribution of the mRNAs in tissues from 15 patients with colorectal cancer. Of 12 cloned sequences studied by slot hybridization, one was substantially reduced in tumours compared with normal tissue. Sequence analysis showed this to code for IgA. In situ hybridization was consistent with slot hybridization and immunohistochemistry. Two mitochondrially encoded sequences had distinct distributions detected by in situ hybridization but did not have detectable quantitative differences in whole tumour or mucosa extracts.
Adenocarcinoma↗
A phase I/II study of the 5-HT3 antagonist GR38032F in the anti-emetic prophylaxis of patients receiving high-dose cisplatin chemotherapy.
A total of 24 patients who were receiving combination chemotherapy (POMB) including cisplatin at a dose of 100-120 mg/m2 were treated with the 5HT3 antagonist GR38032F (GR) as an anti-emetic prophylaxis. GR was given as a 15-min loading infusion followed by a 24-h infusion at three escalating dose levels of 1, 2 and 4 mg/h. In the first 24 h after commencing treatment, six patients had complete control of nausea and vomiting (CR), two had 1-2 emetic episodes (MR) and five had 3-5 emetic episodes (mR). The major response rate (CR + MR) was thus 35%. Eight responding patients (CR or MR) went on to receive oral GR at 8 or 12 mg t.i.d. for 5 days. In this group there was one CR, one MR, two mRs and four failures (F). There was no evidence of an improved therapeutic effect with increasing dose in either the infusion or the oral section of the study, although numbers were limited in the latter part of the trial. Toxicity was mild, with low-grade headache affecting 25% of patients being the most frequent side effect. Pharmacokinetic data was obtained in six patients at each dose level. There was a progressive rise in clearance with increasing dose, indicating that the kinetics are non-linear. However, there was no evidence of an association between high plasma levels and therapeutic efficacy. GR38032F is well tolerated and has promising single-agent activity in preventing vomiting induced by high-dose cisplatin.
Adult↗