Chronic inflammation and cancer

     There are many cancers that are closely related to chronic inflammatory conditions, as shown in Figure 1 below.

    The above pictures have permission to use. Reference: Kamp DW, Shacter E, Weitzman SA. Chronic inflammation and cancer: the role of the mitochondria. Oncology (Williston Park). 2011;25(5):400-13) http://www.cancernetwork.com/ oncology-journal/chronic-inflammation-and-cancer-role-mitochondria

Inflammatory bowel disease (IBD) and colorectal cancer (CRC) have the most significant correlation. Patients with inflammatory bowel disease are 5-7 times more likely to develop colorectal cancer than ordinary people.     

    Approximately 4/10 of patients with ulcerative colitis develop colorectal cancer (ulcerative colitis is an IBD) after 25-35 years. 15

    

    In addition, there is evidence to prove the link between cancer and inflammation: drugs that reduce inflammation also reduce the risk of some cancers. Studies have found that continued use of non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of developing certain cancers. NSAID is a common class of pain relief drugs, including ibuprofen, aspirin, and naproxen. 

    Continuous use of non-aspirin non-steroidal anti-inflammatory drugs (for at least 6 months) reduces the risk of colon cancer by 50%, and long-term use of aspirin reduces the risk of colon cancer by 40%. 16NSAID blocks the protein that causes inflammation, called cyclooxygenase (COX). 17 Aspirin prevents cancer by reducing the metabolite 2-hydroxyglutarate (2HG) in the plasma. The accumulation of 182HG is related to the activation of the oncogene MYC. 19 This is another mechanism by which aspirin prevents cancer. In addition, aspirin also reduces the risk of death from prostate cancer. 20 The US Preventive Services Task Force recommends: “Adults aged 50-59 can use aspirin at low doses to prevent cardiovascular disease (CVD) and colorectal cancer (CRC) for the first time, because 10% of adults aged 50-59 Or higher risk will develop 10 years of CVD, low-dose aspirin use for at least 10 years, will not increase the risk of bleeding, expected to extend life by at least 10 years." twenty one

    The phenomenon of association does not necessarily imply causality. The above-mentioned studies mainly showed the correlation between inflammation and cancer, but did not clearly show that inflammation can cause cancer. Currently, some studies are determining what causes inflammation to cause cancer. These inflammations will be discussed in the following chapters.