Rationale: Cancer cachexia is a complex metabolic syndrome characterized by clinically relevant loss of muscle mass with or without loss of fat mass. To determine how treatment methods can be most effective, full insight in changes in gene expression, body composition, muscle function and muscle metabolism are of great importance.

Objective: Main aim of the study is to investigate the differences in gene expression, body composition, muscle function and muscle metabolism in colon cancer patients compared to controls.

Study design: Observational study Study population: 40 colon cancer patients undergoing a tumor resection (30 primary tumor and 10 liver metastases) and 15 control patients undergoing an inguinal hernia repair (♂, 10) or an abdominal hysterectomy (♀, 5).

Main study parameters/endpoints: Primary study parameter will be gene expression (transcriptomic and polymerase chain reaction analyses of muscle biopsies). Secondary parameters will be body composition (determined in available CT scans and bio impedance analysis and with DEXA), muscle function parameters (grip and knee flexion/extension strength and measured in a biopsy), metabolic markers (measured in fat and muscle biopsies), biochemical markers (measured in blood/serum) and gene expression of fat biopsies.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The investigators expect no additional risk for the subjects due to the proposed measurements. Biopsies will be taken during the planned operation and therefore is not expected to cause a significant increase in burden for the patient. All other measurements are non-invasive, observational measurements with no risk of any harmful side effects.

Inclusion Criteria:

• CC patients:

In order to be eligible to participate in this study, a subject must meet all of the following inclusion criteria:

• Diagnosed with primary colon cancer (30) or liver metastases due to colon cancer(10)

• Eligible for a primary tumor or liver metastases resection procedure

  • Controls:

• Eligible for an inguinal hernia repair (♂, 10) or an abdominal hysterectomy (♀, 5)

Exclusion Criteria:

• CC patients:

A potential subject who meets any of the following criteria will be excluded from participation in this study:

• Having had chemotherapy or an operational procedure of the abdomen in the past 6 months

• Suffering from malabsorption

  • Controls:

• Having had treatment for previous or current tumors

For the control group the investigators include men with inguinal hernia and women eligible for abdominal hysterectomy.

40 colon cancer (CC) patients (♀ and ♂) undergoing primary tumor resection operation (30 patients) or liver metastases surgery (10 patients) and 15 control patients undergoing an inguinal hernia repair (♂, 10) or an abdominal hysterectomy (♀, 5) will be included in the study. Since the investigators do not know the number of patients in the colon cancer group willing to cooperate in the study, the investigators decided to take 5 patients of each control group (50% men and women). Note: during the study the investigators see more men than women joining the study so therefore the investigators raised the number of male controls to 10.