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Introduction Since President Richard M. Nixon declared a “War on Cancer” in 1971, the federal government has spent over $105 billion on cancer research efforts. Has the time, effort, and money spent on this issue been worthwhile? The opinions on this matter vary greatly. Introduction Some prominent professors and researchers have claimed that meaningful progress has been made against cancer. However, they generally only report on the success of treating certain cancers. The cancers for which little or no progress has been made in treatment are not mentioned. Introduction Contrary to these claims of success, the death rate of cancer victims (adjusted for the size and age of the population) has only dropped 5% since 1950. This was according to an article by Gina Kolata of The New York Times. The Cancer Facts The war on cancer has not been effective. It is not decreasing as fast as other devastating ailments. For example, the death rate for stroke/cardiovascular diseases have fallen by 74% and 64% respectively from 1950-2006. Once again, the death rate for cancer has only decreased by 5%. Decrease in stroke/cardiovascular disease is due to: 1. Methods of controlling high blood pressure 2. Use of aspirin 3. Use of beta blockers 4. Use of calcium channel blockers and ACE inhibitors Cancer therapy is obviously decades behind stroke/cardiovascular disease therapy. U.S. Mortality, 2006 Rank Cause of Death No. of Deaths % of All Deaths 1 Heart Diseases 631,636 26.0 2 Cancer 559,888 23.1 3 Cerebrovascular Diseases 137,119 5.7 4 Chronic Lower Respiratory Diseases 124,583 5.1 5 Accidents (unintentional injuries) 121,599 5.0 6 Diabetes Mellitus 72,449 3.0 7 Alzheimer Disease 72,432 3.0 8 Influenza & Pneumonia 56,326 2.3 9 Nephritis 45,344 1.9 Septicemia 34,234 1.4 10 *Includes nephrotic syndrome and nephrosis Sources: U.S. Mortality Data 2006, National Health and Statistics, Centers for Disease Control and Prevention, 2009 Methodological Issues Detection Bias If a patient discovers a malignant tumor early and starts treatment right away, even with a worthless treatment, it appears that the patient lives longer. If a second patient discovers the malignant tumor later, and starts the same worthless treatment, it is not considered nearly as effective. Progression of different cancers ○ Some cancers grow very slowly, therefore the patient may end up living longer. ○ Some cancers progress much faster, therefore shortening the patient’s life span. Publication Bias Only positive results are published What Do We Know About Cancer? Example of Probable or Definite Causes of Cancer (American Cancer Society 2009) External Factors ○ ○ ○ ○ Tobacco Chemicals (e.g., asbestos, benzene, alcohol) Radiation Infections, organisms (e.g., hepatitis B, papilloma virus, Helicobacter) ○ Hormone replacement therapy with estrogen Internal Factors ○ Genetic mutations Inherited Acquired ○ Hormones (e.g., estrogen) ○ Immune disorders (e.g., AIDS) ○ Epigenetic changes ○ Obesity What Do We Know About Cancer? What we don’t know Completely unknown causal mechanism Diagnosis Cancer Therapy Objectives of Therapy Prolongation of life or cure ○ Surgical removal of tumor or cure Improvement of quality of life ○ Chemotherapy, radiation Mild to severe side effects ○ Other drugs to help counteract symptoms from treatment Vomiting, low white blood cell count, heart failure, nerve damage, and diarrhea Value of treatment ○ Cost vs. Benefit analysis Cancer Therapy Metastatic Cancers Cured with Chemotherapy and Radiation Account for a small percentage of cancers Testicular cancer, choriocarcinoma, Hodgkin’s and non-Hodgkin’s lymphoma, leukemia, breast cancer, and ovarian cancer Cancer Therapy Lung Cancer The most common form of cancer The chances of survival are slim if the cancer is not 100% removed. 60% of patients die within the first year after diagnosis. 15% of patients only survive up to 5 years. Cancer Therapy Breast Cancer Slow cancer 5-10 year survival rate if surgery occurs Death rate has declined since 1975 27% likelihood that a person will survive five years if the cancer is metastatic Early detection by screening Cancer Therapy Breast Cancer (Continued) DCIS (ductal carcinoma in situ) ○ 62,000 cases discovered each year ○ In 50% of diagnosed patients, the lesions will not progress and there is no reason for treatment. ○ American Cancer Society (in 2009) recommended that all patients with DCIS undergo some sort of therapy. ○ These patients most likely undergo surgery. ○ It is estimated that, annually, 30,000 patients are unnecessarily treated for DCIS. Prostate Cancer Pancreatic Cancer Common Cancers Current Death and Survival Statistics (American Cancer Society 2009) % of Cancer Deaths One-Year Survival % Five-Year Survival % Lung 28 41 15 Colon/Rectum 9 83 64 Breast 8 >95 89 Pancreas 6 24 5 Prostate 5 * * Leukemia 4 ** 51 Lymphoma 4 82 68 Liver 3 *** <10 Other 33 **** **** Cancer Origin * Survival statistics for prostate cancer are very misleading since they include many treated cancers that would not have harmed (or killed) the patient. ** Leukemia is a heterogenous group of diseases. The five-year survival figure is an average of all types. *** Liver cancer is a rapidly fatal disease in which treatment is ineffective. **** Other cancers are so heterogenous that the reader should consult the American Cancer Society (2009) for specific data. Smart Drugs Smart Drugs Drugs that focus on a particular vulnerability of a type of cancer 90% of these so-called “smart” drugs can cost more than $20,000 for a 12 week treatment. They generally only offer a survival benefit of 2 months or less. 60-80% of oncologists’ revenue comes from the use of anti-cancer drugs in their practices. Smart Drugs Bevacizumab (Avastin) is the 9th largest selling drug in the U.S. It is an intravenous man-made antibody that blocks the growth of VEGF (vascular endothelial growth factor). Tumors and other normal tissue release VEGF to increase blood vessel growth. This helps nourish the tissue. This drug and others like it rarely make a patient live longer, or have a better quality of life. Smart Drugs Bevacizumab (Avastin) - Utility Cancer Evidence for Prolongation of Life; time* Bowel/Rectum Yes, four months (median survival) with other drugs Lung No+ Breast No Kidney No Glioblastoma (Brain) No *Compared to randomized control (if available). + ”No” means a lack of a statistically significant prolongation. Why Has the War on Cancer Failed? We don’t understand the causes of the majority of cancers. Most of the treatments (chemotherapy and radiation) are nonspecific cell killers. The clinical trials have not fostered innovation, and they need reform. The screening for useful drugs against cancer cells hasn’t worked. Animal models of cancer tend to be inadequate. Cancer research has consistently yielded unproductive “facts”. Where Should We Go from Here? We do not understand exactly what causes most cancers. For example, we know that lung cancer can be caused by tobacco use. However, we don’t know exactly how it causes cancer, or how to effectively treat it. Are the causes genetic, epigenetic, or are cancers caused by something else altogether? Without finding the absolute mechanisms and root causes of cancers, we cannot expect to make meaningful progress in this field. What Should We Do Now? Despite the aforementioned lack of knowledge regarding the cure for cancer, we can still decrease the rate of cancer deaths by exploring preventative measures and early cancer screening. What Should We Do Now? Prevention Smoking cessation reduces the risk of lung and other types of cancer. Minimizing hormone therapy reduces one’s risk of contracting breast cancer. Vaccines which are practically 100% effective can be used to prevent: ○ Hepatitis B (which can cause liver cancer) ○ Human Papilloma Virus (which can cause cervical, anal, and penis cancers) Helicobacter, which is a cause of some stomach cancers, can be practically eliminated with antibiotics. Avoid contracting the AIDS virus. This can lead to the development of sarcoma. What Should We Do Now? Prevention (continued) Chemoprophylaxis (preventative medicine) ○ Finasteride and tamoxifen can be used to decrease prostate and breast cancer, respectively, in high risk patients. Decreased alcohol consumption can significantly reduce the occurrences of liver and esophageal cancers. Obesity also can be linked to an increased risk of contracting many different cancers. If we curtail obesity, we decrease the risk of having cancer. What Should We Do Now? Screen for: Cervical cancer Colorectal cancer We should screen for breast cancer, even though it generally leads to overdiagnosis. The benefit of overdiagnosis generally outweighs the harm. We need a better understanding of different cancers and their causes. We need to utilize better animal models in our research. Once the appropriate causes and targets are identified, we need to develop better drugs to treat cancer patients. What Should We Do Now? We definitely need a better understanding of cancer and its causes. If we had this understanding and followed the prevention and screening recommendations, we could greatly reduce the occurrence of cancers. Treatment for other ailments and diseases has progressed greatly along these paths. Why can’t we do this for cancer? Works Cited Spector, Reynold. "The War on Cancer: A Progress Report for Skeptics." 2012. Comp. Eileen Daniel. Taking Sides: Clashing Views in Health and Society. 10th ed. Columbus, OH: McGraw-Hill Higher Education, 2012. 70-79. Print.