How Multimorbidity Affects Cancer Treatment: Analyzing the Impact on Treatment Safety and Effectiveness in Clinical Trials

Cancer survival rates have greatly improved since the 1970s, largely due to the development of new targeted therapies. However, people with cancer often face additional health challenges known as multimorbidity—when someone has more than one chronic condition at the same time. The most common types of multimorbidity in cancer patients are cardiometabolic diseases, including kidney disease, heart disease, and diabetes (high blood sugar). These conditions often develop together and can make each other worse. In fact, people who already have one or more of these conditions before being diagnosed with cancer are more likely to experience worsening health and reduced quality of life.

Multimorbidity is widespread among cancer patients. It is estimated that between 20% and 50% of people with cancer also have kidney disease, 10% to 40% have heart disease, and 8% to 18% have diabetes. Despite the high number of cancer patients affected by multimorbidity, clinical cancer trials often exclude these individuals, which means there is limited evidence on how cancer treatments work for people with multiple chronic conditions. This is a significant gap, as these patients may respond differently to treatments or face more side effects.

Our research aims to fill this gap by analyzing data from past clinical cancer trials. Specifically, we will use individual patient data from a global research database called Vivli. We will focus on understanding how many cancer trial participants had multimorbidity and explore the reasons why some patients drop out of trials. We will also investigate whether cancer treatments are equally effective and safe for people with pre-existing health conditions, such as heart disease, kidney disease, or diabetes.

The results of this study could have important benefits. First, they may help us understand whether excluding patients with multimorbidity from clinical trials is justified, or if these patients should be included in future studies. Second, our findings could lead to better guidelines for monitoring cancer patients who have other chronic conditions, improving their treatment and care.