The characteristics and outcomes of patients with solid tumours admitted to Intensive Care in the West of Scotland

Puxty, Kathryn Ann (2018) The characteristics and outcomes of patients with solid tumours admitted to Intensive Care in the West of Scotland. MD thesis, University of Glasgow.

Abstract

Cancer is one of the commonest conditions among patients admitted to Intensive Care Units (ICU). However, little is known about how it affects likelihood of ICU admission and subsequent clinical progress. What literature does exist is often not generalisable to current UK practice.
The aims of the studies presented in this thesis are to determine the features that are associated with ICU admission in patients with solid tumours; to describe how the solid tumour population in ICU differs from the ICU population without cancer; how this impacts upon survival; and finally, to describe the long-term outcomes of solid tumour patients that have survived ICU and those features associated with mortality.
I undertook a detailed systematic review of the international literature relating to survival following ICU admission for patients with solid tumours. This revealed a paucity of high quality studies and led to recommendations for improving the conduct and reporting of future research in this field.
Using retrospective cohorts from prospectively collected databases, variables relating to patients in the West of Scotland diagnosed with a cancer between 1st January 2000 and 31st December 2009 were analysed. The rate of ICU admission within two years following cancer incidence was investigated, and the factors associated with admission described. The Scottish Intensive Care Society Audit Group (SICSAG) database was used to detail information pertaining to critical illness and to provide data on patients without an underlying tumour that were admitted to ICU during the same study period. Three cohorts were defined: patients with a solid tumour that were admitted to ICU, patients with a solid tumour that were not admitted to ICU, and ICU patients without a cancer diagnosis.
One in twenty patients diagnosed with a solid tumour (5.2%) were admitted to ICU with the majority receiving organ support during their ICU stay. ICU admission tended to occur soon after cancer diagnosis and was therefore likely related to the cancer diagnosis or its treatment. The rate of ICU admission was greatest for bowel malignancies (16.5% of colorectal cancer patients) and for those tumours that require peri-operative ICU support for tumour resection surgery such as head and neck cancers (12.8%), stomach cancer (11.3%) and oesophageal cancer (10.2%). When compared with the ICU population without cancer, patients with solid tumours tended to be older (median age 68 years vs. 59 years, respectively), with a higher proportion of elective hospitalisations (52.7% vs. 10.0%) and were predominantly admitted to ICU with a surgical illness (89.3% vs. 55.0%).
Surgical ICU admissions have a favourable ICU and hospital mortality if they have an underlying cancer diagnosis compared with surgical ICU patients without cancer (hospital mortality 22.9% vs. 28.1%, respectively). A potential explanation for this would be a higher proportion of level 2 admissions, lower utilisation of multi-organ support and an opportunity for pre-operative optimisation within the cancer group. ICU cancer patients admitted with a medical diagnosis have poorer short-term survival than those without cancer (hospital mortality 49.1% vs. 41.7%, respectively) and this difference is even more pronounced in those that received organ support (62.5% vs. 46.2%).
In patients that survive an admission to ICU the presence of cancer has the largest impact upon mortality risk in the longer-term with a risk of death over three times greater than in the population of ICU survivors without cancer. Long-term survival varies considerably by underlying tumour type with four-year survival varying from 10.0% in patients with hepatocellular carcinoma to 73.3% in patients with testicular cancer. Cancer-related factors such as tumour stage have an important role in determining mortality risk in the longer term for survivors of ICU with cancer. In patients with colorectal cancer that had survived an ICU admission the risk of death after six-months was significantly higher in patients with Dukes D stage vs. Dukes A (HR 8.66).
The work presented in this thesis systematically reviews and summarises the current published outcomes of patients with solid tumours admitted to ICU, demonstrates that among the solid tumour population ICU admission is common and shows that short-term outcomes vary significantly by features associated with both the critical illness and the underlying tumour type. In patients that survive an ICU admission the presence, type and stage of cancer is important for determining on-going mortality risk. This information may be used when clinicians are discussing potential outcomes following admission to critical care with cancer patients. Future studies should focus on the administration of treatments for cancer after critical illness and whether they differ from those received by those patients without an ICU admission. Prospective studies are required to describe the pre-ICU deteriorations in physiology in cancer patients with critical illness including those considered, but not admitted, to ICU. Outcomes for this latter group are unknown and given the high burden of illness severity documented in ICUs within the UK, these studies may identify a group of patients for whom critical care would be beneficial but is not currently provided.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: Critical care, ICU, cancer, survival, outcomes.
• Subjects: R Medicine > R Medicine (General); R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Funder's Name: Cancer Research UK (CRUK)
• Supervisor's Name: Quasim, Dr. Tara and Morrison, Dr. David
• Date of Award: 2018
• Depositing User: Dr Kathryn A Puxty
• Unique ID: glathesis:2018-8910
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Apr 2018 10:48
• Last Modified: 20 Jul 2018 12:40
• URI: https://theses.gla.ac.uk/id/eprint/8910