Durdey, Paul;
(1990)
The perioperative assessment of rectal neoplasia.
Masters thesis (M.S), UCL (University College London).
Text
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Abstract
Despite technical advances and introduction of adjuvant therapy, mortality from rectal neoplasia remains static. Many patients present with disseminated disease, beyond cure by surgery alone. Even after "curative" excision, recurrence, both local and distant can occur. The objectives of this thesis were twofold, firstly to assess accurately the extent of tumour spread at presentation, and secondly to examine certain biological parameters of these growths. Thus high risk patients could be identified, which would allow a more rational approach to treatment of the individual. An initial retrospective study demonstrated that patients with local intrapelvic spread of tumour had significantly higher local recurrence and lower survival rates than those without spread. Patients with clinically fixed tumours due to peritumoral fibrosis had recurrence and survival rates comparable with the latter group. A prospective study revealed that digital rectal examination is inaccurate in assessing local status of the tumour. Pelvic computerised tomography (CT) proved significantly superior in assessing presence or absence of local spread. Serum levels of carcinoembryonic antigen (CEA) and acute phase reactant proteins (APRP) appear able to refine the results of CT, and accurately identified inflammatory fixation. Clinical examination and routine measurement of liver function could not identify the majority of liver secondaries. Hepatic CT proved superior to ultrasound in detecting macroscopic metastases. Serum CEA correlated with tumour load. "Occult" metastases were not detected by any modality. Three aspects of biological behaviour were addressed, tumour differentiation, a possible mechanism of tumour infiltration, and tumour growth rate. Degree of histological differentiation of the main tumour could not be determined accurately by examination of pre-operative biopsies, even if multiple. Flow cytometric analysis was significantly better than subjective assessment. Elevated levels of three proteolytic enzyme, collagenase, collagenase-like peptidase, and cathepsin B were Identified In recto-sigmoid tumours. High cathepsin B levels appeared to correlate with local tumour infiltration. Tumour growth rate was assessed by production of an In vitro model, multlcellular tumour spheroids (MTS) from individual carcinomas. Growth rates of MTS In vitro correlated inversely with patient survival. This perioperative assessment may thus allow a more rational and individual approach to treatment of rectal neoplasia.
Type: | Thesis (Masters) |
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Qualification: | M.S |
Title: | The perioperative assessment of rectal neoplasia |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Thesis digitised by ProQuest. |
Keywords: | Health and environmental sciences; Tumor spread |
URI: | https://discovery.ucl.ac.uk/id/eprint/10123590 |
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