Evaluating Prognosis and Prognostic Factors in Critically Ill Patients With and Without Cancer: An Observational Comparative Study

Objective There is a lack of published data on the prognosis and factors predicting mortality in the intensive care unit (ICU) for cancer patients in our region. This study aims to examine the outcomes and factors affecting mortality in cancer patients admitted to the ICU in the Eastern Province of Saudi Arabia, in comparison to non-cancer patients. Materials and methods This retrospective study analyzed data from patients admitted to a single tertiary center's critical care unit between January 2022 and October 2023. We compared cancer patients (solid and hematological malignancies) to non-cancer patients (admitted under internal medicine), excluding elective cases and those with pre-existing Do Not Resuscitate (DNR) orders. Results A study of 313 patients, comprising 165 (53.7%) cancer patients and 148 (47.3%) non-cancer patients, revealed the following findings: Septic shock (74.1%) and respiratory failure (55.3%) were the primary reasons for ICU admission. Among cancer patients, breast cancer (20%) was the most prevalent, followed by colorectal (15.2%) and lung cancers (7.3%). Most oncology patients (78.8%) had metastasis. Median ICU and hospital stays were four and 12 days, respectively, with no significant differences between cancer and non-cancer patients. Cancer patients had significantly higher ICU mortality (58.8% vs. 36.5%) and in-hospital mortality rates (72.7% vs. 43.9%) compared to non-cancer patients. Multivariate analysis identified cancer diagnosis and ischemic heart disease as independent predictors of mortality. Mechanical ventilation was the sole predictor of ICU mortality among cancer patients, while DNR status predicted ICU mortality among non-cancer patients. Conclusion Critically ill cancer patients admitted to the ICU face higher mortality rates compared to non-cancer patients despite similar lengths of stay. Invasive mechanical ventilation emerges as a key predictor of mortality among cancer patients. Conversely, cancer diagnosis predicts mortality across both groups. These findings underscore the importance of discussing end-of-life care goals with advanced-stage cancer patients requiring mechanical ventilation.