Screening and the association between cervical cancer and known reproductive and hormonal factors
<p>Epidemiological studies have shown associations between reproductive and hormonal factors and cervical carcinogenesis, but have had limited information on previous cervical screening. Screening is known to reduce the incidence of invasive cervical cancer (ICC) and there is some evidence tha...
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| Format: | Thesis |
| Language: | English |
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2022
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| _version_ | 1826310650902609920 |
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| author | Chiuri, K |
| author2 | Beral, V |
| author_facet | Beral, V Chiuri, K |
| author_sort | Chiuri, K |
| collection | OXFORD |
| description | <p>Epidemiological studies have shown associations between reproductive and hormonal factors and cervical carcinogenesis, but have had limited information on previous cervical screening. Screening is known to reduce the incidence of invasive cervical cancer (ICC) and there is some evidence that reproductive and hormonal factors affect screening uptake. The main aim of this thesis was to examine the risk of cervical neoplasia i.e., pre-invasive cervical intraepithelial neoplasia grade 3 (CIN3) and ICC, associated with reproductive factors, namely parity and age at first birth, and hormonal factors, namely use of oral contraceptives (OC) and menopausal hormone therapy (MHT), taking into account confounding by screening history.</p>
<p>Analyses involved over 800,000 women in the Million Women Study with linked NHS Cervical Screening Programme records, including over 1400 cases of CIN3 and 1000 cases of ICC. Using logistic regression, non-attendance for cervical screening was found to vary considerably according to reproductive and hormonal factors. Using Cox regression to estimate relative risks of cervical neoplasia, I found that early childbearing was associated with increased risks of CIN3 and ICC after adjustment for multiparity. For hormonal factors, while use of OCs was not associated with overall ICC, there were heterogenous associations by histo-type. In particular, among users of OCs risks were increased for squamous cell carcinoma (SCC) but reduced for adenocarcinoma (AC). The increased risk of SCC with increasing duration of use of OCs persisted for up to 30 years after cessation of use. Use of MHT was associated with a reduction in risk of ICC which was also heterogenous by histo-type; for SCC there was a significant reduction in risk with MHT use, but no significant association with AC.</p>
<p>This large prospective analysis confirms that early childbearing contributes to cervical neoplasia risk and suggests that long duration use of OCs confers a persistent risk of invasive SCC. This study also provides new evidence that hormonal risk factors for cervical cancer may vary between the two major histo-types, SCC and AC, highlighting the need for further research on these cancers.</p> |
| first_indexed | 2024-03-07T07:55:03Z |
| format | Thesis |
| id | oxford-uuid:c9afe951-90ab-40e2-a521-811a7de64add |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:55:03Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | oxford-uuid:c9afe951-90ab-40e2-a521-811a7de64add2023-08-08T15:48:10ZScreening and the association between cervical cancer and known reproductive and hormonal factorsThesishttp://purl.org/coar/resource_type/c_db06uuid:c9afe951-90ab-40e2-a521-811a7de64addEpidemiologyCancer EpidemiologyEnglishHyrax Deposit2022Chiuri, KBeral, VBarnes, ISweetland, S<p>Epidemiological studies have shown associations between reproductive and hormonal factors and cervical carcinogenesis, but have had limited information on previous cervical screening. Screening is known to reduce the incidence of invasive cervical cancer (ICC) and there is some evidence that reproductive and hormonal factors affect screening uptake. The main aim of this thesis was to examine the risk of cervical neoplasia i.e., pre-invasive cervical intraepithelial neoplasia grade 3 (CIN3) and ICC, associated with reproductive factors, namely parity and age at first birth, and hormonal factors, namely use of oral contraceptives (OC) and menopausal hormone therapy (MHT), taking into account confounding by screening history.</p> <p>Analyses involved over 800,000 women in the Million Women Study with linked NHS Cervical Screening Programme records, including over 1400 cases of CIN3 and 1000 cases of ICC. Using logistic regression, non-attendance for cervical screening was found to vary considerably according to reproductive and hormonal factors. Using Cox regression to estimate relative risks of cervical neoplasia, I found that early childbearing was associated with increased risks of CIN3 and ICC after adjustment for multiparity. For hormonal factors, while use of OCs was not associated with overall ICC, there were heterogenous associations by histo-type. In particular, among users of OCs risks were increased for squamous cell carcinoma (SCC) but reduced for adenocarcinoma (AC). The increased risk of SCC with increasing duration of use of OCs persisted for up to 30 years after cessation of use. Use of MHT was associated with a reduction in risk of ICC which was also heterogenous by histo-type; for SCC there was a significant reduction in risk with MHT use, but no significant association with AC.</p> <p>This large prospective analysis confirms that early childbearing contributes to cervical neoplasia risk and suggests that long duration use of OCs confers a persistent risk of invasive SCC. This study also provides new evidence that hormonal risk factors for cervical cancer may vary between the two major histo-types, SCC and AC, highlighting the need for further research on these cancers.</p> |
| spellingShingle | Epidemiology Cancer Epidemiology Chiuri, K Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title | Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title_full | Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title_fullStr | Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title_full_unstemmed | Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title_short | Screening and the association between cervical cancer and known reproductive and hormonal factors |
| title_sort | screening and the association between cervical cancer and known reproductive and hormonal factors |
| topic | Epidemiology Cancer Epidemiology |
| work_keys_str_mv | AT chiurik screeningandtheassociationbetweencervicalcancerandknownreproductiveandhormonalfactors |