The impact of socio-economic factors on outcome from breast cancer

Henley, Natasha Cherono (2006) The impact of socio-economic factors on outcome from breast cancer. MSc(R) thesis, University of Glasgow.

Abstract

For many years it has been recognised that a deprivation gap exists in breast cancer. The aim of this thesis is to identify if there remains a survival gap between affluent and deprived women and to what extent treatment and pathology are responsible. All women treated for primary operable invasive breast cancer in Glasgow between 1995 and 1998 were analysed. In total, 1717 women were treated. Median follow up was just over 6 years. Overall 5 year survival was 80.4%. There was a trend for worse survival in the most deprived group (83.9% vs. 77.8% in the most affluent group) but this was not significant. Interestingly, deprived women had larger, node positive tumours and were more likely to be symptomatic but this did not affect survival. On multivariate analysis age, Nottingham prognostic index (NPI) and oestrogen receptor (ER) status were independent predictors of survival. These results suggest that the deprivation gap may no longer exist in Glasgow. While, follow up may not be long enough to identify a deprivation gap, the introduction of standardised treatment by multidisciplinary teams may have had an impact on narrowing the deprivation gap. Surgical treatment for breast cancer can be by mastectomy or conservation surgery. The differences in survival suggest that perhaps surgeons themselves are treating affluent and deprived women differently. Women diagnosed between 1996 and 2001 were analysed to see if surgical treatment varied between affluent and deprived women. Deprived women were treated appropriately and it was tumour size that determined surgery not biased treatment. There was, however, significant variation in mastectomy rate between hospitals suggesting that there is a lack of consensus on the best surgical management of primary operative breast cancer. It has previously been shown that affluent women not only have a higher incidence of breast cancer but they are also more likely to have ER positive disease. ER positive breast cancer is more likely to respond to hormonal therapy and is less likely to recur, resulting in a better prognosis. It is also associated with nulliparity, late age at first birth, late menopause and HRT use. All of these reproductive factors have increased in the last 20 to 30 years but more so for affluent women. Two cohorts of patients were compared. The first were diagnosed 1980-1988 and had ER status determined by ligand binding assay, the second, diagnosed between 1996 and 2001, had ER determined by immunohistochemistry. The proportion of ER positive tumours rose from 50.1% in the early cohort to 79.3% in the late cohort. This increase was independent of age, deprivation or hospital of diagnosis (p<0.001). The proportion of ER positive breast cancers increased for all deprivation categories but there was no significant difference between the most and least deprived. Some of this rise is due to changes in the methodology of determining ER status; however, this does not explain all of the difference. Increases in the prevalence of the aetiological factors for ER positive breast cancer are, in some part, responsible. Differences in the host response to the tumour may be responsible for survival differences. The systemic inflammatory response, as measured by C-reactive protein (CRP) to cancer predict prognosis in a variety of solid tumours. In addition, deprived people appear to have a raised "background" level of inflammation which may contribute to survival differences between rich and poor. There no longer appears to be a deprivation gap in survival for women with breast cancer. Differences in surgical treatment do, however, exist but this appears to be due to bigger tumours in deprived women. Hormonal, aetiological factors for ER positive breast cancer have increased overall for all women but this does not seem to contribute to socioeconomic differences in tumour pathology. The systemic inflammatory response may play a role in predicting survival from breast cancer but it does not appear to differ between social classes. Improvements in diagnosis and delivery of treatment must therefore play the largest role in narrowing the deprivation gap.

• Item Type: Thesis (MSc(R))
• Qualification Level: Doctoral
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Cooke, Prof. Tim
• Date of Award: 2006
• Depositing User: Mrs Monika Milewska-Fiertek
• Unique ID: glathesis:2006-39038
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 20 Dec 2018 16:23
• Last Modified: 20 Dec 2018 16:27
• URI: https://theses.gla.ac.uk/id/eprint/39038

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