by Alex Shimanovksy, MD
Cancer is among the leading causes of death worldwide. By 2040, the number of new cancer-related death is expected to rise to 16.5 million1. Cancer is primarily a disease of an aging population; this reflects on the impressive gains modern medicine made against infectious and cardiovascular diseases which were and are the leading causes of death, respectively. This transition marks a pronounced epidemiological shift, where oncological diseases will become the number one cause of death worldwide. Unfortunately, while the pace of scientific research and cancer-related treatments have accelerated, we are far from finding a cure.
Cancer is viewed as insidious and relentless, the king of human suffering. As oncologists, we are trained to try our hardest to try and “cure” the disease. However, as we gain knowledge on the biology of the disease, the further away a complete cure seems to be. We now understand that breast cancer in one person is different from breast cancer in another. Even within the same tumor, studies have demonstrated the heterogeneity of individual cancer cells2. The increase in our understanding of heterogeneity has led to advancements in specific therapeutic approaches that includes immunotherapy and target therapy. These treatments have yielded huge gains, with improved overall survival, fewer side-effects and improved patient quality of life; far better than the “sledgehammer” approach of chemotherapy. However, while these treatments may prolong life and reduce suffering, eventually the cancer cells evolve and mutate, and they start to evade the treatment.
The constant evolution and the complexity of cancer biology creates an enormous challenge towards finding a cure. Let alone a “silver bullet” – a single pill that would cure cancer. One tried-and-true approach to reduce the incidence and mortality of diseases is through prevention. By improving sanitation and with the use of vaccines, we were able to reduce infections. Similarly, smoking cessation and improvement in hypertension and cholesterol management help reduce advanced cardiovascular disease. Sure, antibiotics and cardiac stents have their roles, but prevention of these diseases clearly improved mortality as demonstrated by our aging population.
Like the evolution of cancer cells, the causation of cancer is shifting. While tobacco-use and cancer-causing infections (I.e., HPV) are declining, our ever-aging population is on the rise. Furthermore, the rise in obesity rates could make it the number one risk of carcinogenesis in the developing world. According to a Lancet Public Health report, obesity accounts for up to 60% of endometrial, 36% of gallbladder, 33% of kidney and 17% pancreatic cancers3. A report by JAMA Oncology found that about half of cancer related deaths can be prevented through lifestyle modification such as exercise, avoiding heavy alcohol drinking and smoking cessation (primary prevention)4.
The lag time between cancer diagnosis and the development of cancer cells can be up to 20 years. Mammography, colonoscopy, and low-dose CT (Computed Tomography) screening have demonstrated that early detection can reduce mortality by as much as 20%. Development of screening techniques such as liquid DNA, new imaging techniques and screening technologies can help detect those cells early so that they can be treated before it has time to spread.
Consequently, while specific cancer therapy can prolong life and improve survival, we must focus on preventing the development of disease in the first place. Lifestyle modification, vaccinations and development of screening techniques can reduce cancer-related mortality and death in the future.
1. Shah SC, Kayamba V, Peek RM, Jr., Heimburger D. Cancer Control in Low- and Middle-Income Countries: Is It Time to Consider Screening? J Glob Oncol. Mar 2019;5:1-8. doi:10.1200/JGO.18.00200
2. Meacham CE, Morrison SJ. Tumour heterogeneity and cancer cell plasticity. Nature. Sep 19 2013;501(7467):328-37. doi:10.1038/nature12624
3. Sung H, Siegel RL, Rosenberg PS, Jemal A. Emerging cancer trends among young adults in the USA: analysis of a population-based cancer registry. Lancet Public Health. Mar 2019;4(3):e137-e147. doi:10.1016/S2468-2667(18)30267-6
4. Song M, Giovannucci E. Preventable Incidence and Mortality of Carcinoma Associated With Lifestyle Factors Among White Adults in the United States. JAMA Oncol. Sep 1 2016;2(9):1154-61. doi:10.1001/jamaoncol.2016.0843