Chemoprevention: How can it help reduce the risk of cancer?, Health News, ET HealthWorld
By Dr (Prof) Vijay PatilMumbai: Cancer is a leading cause of death worldwide, and its incidence is expected to increase in the coming years. Chemoprevention, the use of drugs to prevent or reverse the development of cancer, has emerged as a promising approach to reducing cancer risk. Factors that categorise a person to be at risk of developing cancer include older age, personal or family history of cancer, tobacco use, obesity, alcohol consumption, viral infections such as human papillomavirus (HPV), exposure to specific chemicals, and radiation. People who are at high risk of developing cancer or have a family history of cancer can participate in trials of chemoprevention. The ideal chemopreventive agents should be orally administered, without side effects, inexpensive, and highly effective. A large number of natural and synthetic compounds with anti-cancer properties have been identified and classified based on their mechanism of action or chemical structure. The major classes of chemopreventive agents are antioxidants, anti-inflammatory agents, and anti-hormonal agents. Antioxidants such as selenium and Vitamin E quench free radicals, induce cell apoptosis, and enhance immune function. Anti-inflammatory agents such as lycopene and beta-carotene not only quench singlet oxygen but also lipid peroxidation. Anti-hormonal agents such as tamoxifen and finasteride reduce cell proliferation by blocking hormone receptors. Chemopreventive agents can be classified according to their source, including hormonal, medication, diet-related agents, and vaccines. Primary chemoprevention involves administering chemopreventive agents to healthy populations or those at increased risk of cancer. Secondary chemoprevention is for patients with premalignant lesions that may progress to an invasive disease. Tertiary chemoprevention is done for patients who have undergone prior treatment to prevent disease recurrence or a second primary disease. Benefits of chemoprevention A major postulated benefit of chemoprevention is prolongation of life span due to controlled disease or prevention of disease recurrence. Chemopreventive drugs can also lower the risk of developing cancer. The drugs prescribed for chemoprevention can have short-term as well as long-term side effects, although their benefits outweigh the risks. For example, tamoxifen, when taken every day for a maximum of five years, has been shown to lower the incidence of breast cancer by 50 per cent among women at high risk of breast cancer but can cause side effects such as hot flashes and pose a risk of developing endometrial cancer. Chemoprevention for Breast and Cervical Cancer Chemoprevention is more prevalent in breast cancer than any other cancer, although it has also been used in prostate and colon cancers. The use of tamoxifen and raloxifene in high-risk patients for developing breast cancer is a good example of the prevalence of chemopreventive agents in clinical practice. Chemoprevention has an impact on various steps during tumor initiation, promotion, and progression. It can lower the risk of developing a new cancer or reduce the chances of disease recurrence. Persistent human papillomavirus (HPV) infection is the primary cause of cervical cancer, which is the leading cause of cancer death in women. Studies suggest that chemoprevention that is vaccination against HPV can reduce the incidence of cervical pre-cancer and cervical cancer. A Cochrane review of 26 trials with over 73,000 participants showed that HPV vaccination leads to the prevention of cervical pre-cancer, particularly in adolescent girls and women. In conclusion, chemoprevention has emerged as a promising approach to reducing cancer risk. The identification of new chemopreventive agents and their use in clinical practice can play a crucial role in preventing and controlling cancer. It is important to identify individuals at high risk of developing cancer and administer chemopreventive agents to reduce their risk. With continued research and development, chemoprevention has the potential to be a cost-effective intervention that can prolong life span and reduce the incidence of cancerDr (Prof) Vijay Patil, Consultant (Medical Oncology), P D Hinduja Hospital & Medical Research Centre, Khar(DISCLAIMER: The views expressed are sole of the author and ETHealthworld does not necessarily subscribe to it. ETHealthworld.com shall not be responsible for any damage caused to any person/organisation directly or indirectly.)
Sunday, April 9, 2023 at 9:33 am