Processed meats are red meat and poultry products that have been preserved by smoking, curing, salting, and/or the addition of chemical preservatives. Examples of processed meat include hot dogs, sausages, bacon, and luncheon meats. Processed meat is associated with an increased risk of colorectal cancer, and evidence also suggests it is associated with stomach cancer. The International Agency for Research on Cancer (IARC) classifies processed meat as a Group 1 carcinogen (meaning it is carcinogenic to humans), and red meat as a Group 2A carcinogen (meaning it is probably carcinogenic to humans).

However, more research is needed to understand how red meat and processed meats influence cancer risk. The increased risk may be explained by the iron and fat content in red meat, and/or the salt and nitrates/nitrites in processed meats. Additionally, when meat is cooked at high temperatures, substances are formed that may cause cancer.

Source - https://progressreport.cancer.gov/prevention/diet_alcohol/red_meat