Comorbidity in lung cancer: influence on treatment and survival

Grose, Derek B. (2016) Comorbidity in lung cancer: influence on treatment and survival. MD thesis, University of Glasgow.

Abstract

Lung cancer is the commonest cancer in Scotland and survival rates for patients in Scotland appear lower than in many other European countries. Although this variation in survival is usually interpreted as evidence of variation in facilities, access to care and clinical practice it is possible that the increased comorbidity and poor performance status of the Scottish population may contribute to the observed disparities in treatment and outcomes, although this has never been proven.

The overall aim of the Thesis was to examine the impact of comorbidity in lung cancer, to attempt to quantify the extent and severity of comorbidity and to explore its relationship with treatment and survival.

Between 2005 and 2008 all newly diagnosed lung cancer patients coming through the Multi-Disciplinary Teams (MDTs) in four Scottish Centres were included in the study. Patient demographics, World Health Organization/Eastern Cooperative Oncology Group performance status (PS), clinic-pathological features, stage, comorbidity, markers of systemic inflammation and proposed primary treatment modality were all recorded. Information on date of death was obtained via survival analysis undertaken by the Information Service Division (ISD) of NHS Scotland. Death records were complete until 1 June 2011, which served as the censor date for those alive.

Chapter 4 examines the variations in demographics and baseline characteristics seen between the centres and reveals significant differences between the centres such as deprivation, stage at presentation, PS and treatments offered.

Chapter 5 explores the relationship between comorbidity and the patient cohort. It shows that comorbidity can be quantified using a scoring index (the Scottish Comorbidity Scoring System (SCSS)) and that increasing comorbidity is associated with treatment centre and socio-economic status, with the most deprived patients having increased levels of co-morbidity. It also demonstrates that comorbidity appears to have an impact on treatment offered.

Chapter 6 examines the relationship between systemic inflammation (utilizing the well established modified Glasgow Prognostic Score (mGPS)) and outcome in the patient cohort. It confirms previous work supporting the use of the mGPS in predicting lung cancer survival and also shows how it might be used to provide more objective risk stratification in patients diagnosed with lung cancer.

Chapter 7 explores the relationship between a novel comorbidity scoring system (SCSS) and the already established Charlson Comorbidity Index (CCI) and the modified Glasgow Prognostic Score (mGPS). This study aimed to determine which of these factors provided the most accurate information on survival. The novel comorbidity scoring system, the SCSS compares very favourably with the more established CCI. In addition this study demonstrates clear differences between patients having potentially radically treatable disease (NSCLC stage I – IIIa) and disease which would generally be considered incurable (NSCLC IIIb/IV and SCLC).

Chapter 8 examines the reasons for the clinician decision-making process and if these reasons do indeed mirror the individual patient’s demographics, fitness and stage. In the majority of patients, both in the early and advanced stage at presentation, the treatment decision appears to be appropriate given the recorded fitness, PS and comorbidity. However in a small but significant number of patients there did appear to be discrepancies between the clinician’s reasons for sub-optimal therapy and the recorded objective assessment of the patient in question.

The work presented in this thesis has demonstrated the significant extent of comorbidity in lung cancer and the important role it appears to play (along with systemic inflammation) in determining treatment choice and survival.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: lung cancer, epidemiology, comorbidity.
• Subjects: R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Supervisor's Name: Milroy, Dr. Robert and McMillan, Prof. Donald
• Date of Award: 2016
• Depositing User: Dr Derek Grose
• Unique ID: glathesis:2016-7079
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 24 Mar 2016 14:34
• Last Modified: 12 Apr 2016 08:38
• URI: https://theses.gla.ac.uk/id/eprint/7079