Research project Physical activity, the immune system and colon cancer - is there a connection?
Colorectal cancer is the third most common cancer in the world and the second most common cancer as a cause of death. The incidence is increasing in Sweden and is now estimated at about 4000 for colon cancer and 1900 for rectal cancer.
Physical activity, both before and after diagnosis, reduces the risk of developing colorectal cancer and correlates with both reduced overall and cancer-specific mortality. The causal relationship between physical activity and reduced mortality is not understood. It has been found in preclinical studies that the density of immune cells in the microenvironment of the tumor correlates with the prognosis. In animal models, it has been shown that exercise can lead to both slower growth of tumors and smaller tumor mass. Physical activity has also been shown to mobilize immune system cells from lymphoid tissue to other parts of the body.
Sarcopenia is a progressive muscle disease characterized by low muscle strength and low muscle quality or quantity. Radiologically, from a cross-section in the lumbar level, one can estimate both muscle mass and muscle quality. Furthermore, studies have shown a connection between prognosis in colorectal cancer and these radiological measures.
Of course, obtaining a colon cancer diagnosis and later undergoing surgery is life-changing, which can change one's life and the way one looks at life. Having a high level of physical activity after surgery has been shown to correlate with postoperative recovery. Furthermore, patients with higher self-rated physical activity before planned colorectal cancer surgery have also been shown to estimate their own recovery better. Helping patients maintain their physical activity even after colon cancer diagnosis can be an important tool to both facilitate postoperative recovery and maintain quality of life in patients.
The thesis work includes four parts of the project and aims to increase knowledge about the connection between physical activity, colorectal cancer and the immune system and also body composition. We also want to investigate which factors for the individual patient are important for maintaining physical activity even after diagnosis.
1. PACOS – Physical activity and its impact on colon cancer surgery
Prospective cohort study in which patients diagnosed with colon cancer undergo physical tests preoperatively. High and low physical activity are compared in groups regarding the presence of immunoinfiltration in the tumor microenvironment
(Data collection in progress)
2. Retrospective study where the Västerbotten Cohort (VIP) registry is used and coordinated with the Swedish Colorectal Cancer Registry. Patients are divided into groups depending on their response to the 5-point scale regarding physical activity in their free time. The groups are compared for the presence of immunoinfiltration in the microenvironment of the tumors.
Density of CD3+ and CD8+ cells in the microenvironment of colorectal cancer according to pre-diagnostic physical activity.
Renman D, Gylling B, Vidman L, Bodén S, Strigård K, Palmqvist R, Harlid S, Gunnarsson U, Van Guelpen B. Cancer Epidemiol Biomarkers Prev. 2021 Oct 4. Online ahead of print.
PMID: 34607838.
3. Retrospective study where the Västerbotten cohort (VIP) registry is used and coordinated with the Swedish Colorectal Cancer Registry. Patients are divided into two groups (high and low physical activity) according to their response to the 5-point scale regarding physical activity in their free time. The groups are compared for the occurrence of sarcopenia and myosteatosis at diagnosis, respectively. Furthermore, survival analysis is also carried out to investigate whether there is an additive effect of both being physically inactive and being sarcopic or myosteatotic in diagnosis.
(Script work in progress)
4. Qualitative study aimed at describing how physically active people diagnosed with colon cancer are affected by their diagnosis and whether or how their exercise habits change after diagnosis before starting treatment.
Attitudes to and Experiences of Physical Activity After Colon Cancer Diagnosis Amongst Physically Active Individuals - A Qualitative Study
Renman D, Strigård K, Palmqvist R, Näsvall P, Gunnarsson U, Edin-Liljegren A. Cancer Control. 2022 Jan-Dec. PMID: 36066380
DOI:10.1177/10732748221119352
