Colon cancer is something that two people in my life have had and have also died from. They were completely different in every way. One of the people was a 24-year-old female that worked as a firefighter for two years at the time of her diagnosis. She had no family history of colon cancer and did not drink alcohol or use tobacco products. Her only symptom was unexpected weight loss. The other was a 50-year-old male with no family history of the disease but drank alcohol and smoked cigarettes regularly. He was diagnosed shortly after having his first routine colonoscopy. He was asymptomatic. They both died within two years after their diagnosis. 
Genetics: Alterations and Symptoms
Genetics can play a role in having colon cancer because “hereditary nonpolyposis colorectal cancer is the methylation of a gene whose protein product repairs damaged DNA” (Huether