Radiotherapy for Rectal Cancer: An Exploration of Factors Associated with Symptoms and Tumour Response

O'Gorman, Claire (2014) Radiotherapy for Rectal Cancer: An Exploration of Factors Associated with Symptoms and Tumour Response. PhD thesis, Waterford Institute of Technology.

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Preoperative radiotherapy is widely accepted as standard treatment for rectal cancer as it is associated with remarkable improvements in locoregional control. However, both the illness and treatment lead to a number of side effects which may negatively influence QoL. Few studies have investigated this specifically in relation to rectal cancer patients, particularly regarding fatigue. KRAS is mutated in 30%-50% of rectal cancer cases and mediates the expression of the cytokines IL-6 and IL-8. Exploration of KRAS status and expression levels of IL-6 and IL-8 as factors associated with radiosensitivity, in terms of tumour response and symptom presentation would be helpful in guiding treatment protocols, as individuals react differently due to inherent radiosensitivity. Therefore, the aim of this two armed study was to 1) investigate symptom presentation and 2) explore potential factors associated with radiosensitivity in rectal cancer patients receiving preoperative radiotherapy. An exploratory, correlational design was adopted which used nonprobability, convenience sampling to select suitable participants. Data in relation to symptoms and QoL was collected at 4 time points over a 10 week period. Tumour tissue was analysed to determine KRAS status and expression levels of IL-6 and IL-8, with these cytokines also measured in blood plasma using micro-array technology. Data was analysed using SPSS. The final sample consisted of 35 rectal cancer patients, with ages ranging from 34-82 years. One-way repeated measures ANOVA found that levels of fatigue, bowel function symptoms, nutrition, pain, dermatological issues and urinary function symptoms changed significantly over time. Lower levels of global QoL were associated with increases in fatigue, constipation, bloating, blood and mucous in stool, stool frequency, appetite loss, weight worry, dry mouth, pain, urinary frequency and lower levels of sexual interest. KRAS status was not associated with tumour response to treatment or expression of IL-6 and IL-8, although plasma levels of these cytokines were indicative of tumour size. Furthermore, both cytokines correlated with faecal incontinence. These findings demonstrate the importance of the close monitoring and management of symptoms during radiotherapy for rectal cancer in order to optimise QoL and avoid interruptions to treatment. KRAS status is not indicative of tumour response, although further subtype analysis is required. In addition, IL-6 and IL-8 may be useful as potential biomarkers in terms of tumour size.

Item Type: Thesis (PhD)
Uncontrolled Keywords: Rectal cancer, Radiotherapy
Departments or Groups: *NONE OF THESE*
Divisions: School of Health Sciences > Department of Nursing
Depositing User: Derek Langford
Date Deposited: 25 Sep 2014 14:15
Last Modified: 22 Aug 2016 10:27

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