David Koch was incredibly gifted, both genetically and financially, and became a chemical engineer, businessman, political activist, and philanthropist.  With one of his brothers, he grew a vast inheritance into joint ownership of Koch Industries, and at the time of his death he was the 11th richest person in the world, worth $48 billion.  He attended excellent schools, Deerfield Academy and Massachusetts Institute of Technology (MIT), where he earned his bachelor's degree in 1962 and a master's degree in chemical engineering in 1963. He was one of the best basketball players ever to play for MIT, averaging 21 points per game, and for many years he held their single-game scoring record of 41 points. 
In 1992, at age 52, he was diagnosed with advanced prostate cancer that had already spread beyond the prostate.  Most cases of prostate cancer never kill a person, but the younger the age at first diagnosis, the more likely it is to be the aggressive type of the cancer that spreads through the body.  Koch was treated many times with radiation, surgery and anti-male hormones, but the cancer always came back. His  doctors told him he had only a few years to live, yet he fought the disease for 27 years.  His brother recalled that, "David liked to say that a combination of brilliant doctors, state of the art medications and his own stubbornness kept the cancer at bay."  He died at age 79 on August 23, 2019, presumably from the progression of his prostate cancer. 
A Life of Politics and Philanthropy 
David Koch was born in Wichita, Kansas in 1940.  His father, Fred Chase Koch, was a chemical engineer and entrepreneur who founded an oil refinery that eventually became Koch Industries, which is listed by Forbes Magazine as the second-largest privately held company in the United States.  After Fred Koch's death in 1967 and many legal battles, his second son, Charles, primarily ran the company from Kansas, while David set up an office in New York City.  Charles and David bought out their other two brothers, Frederick and William.  David and Charles became co-owners of Koch Industries, each with 42 percent of the company.  They both used their wealth to support the Libertarian and Republican parties and candidates.  In 1980, David Koch was the vice-presidential running mate in the unsuccessful campaign of Ed Clark, the Libertarian candidate for U.S. President. The ticket received one percent of the votes.  In 1984, Koch broke with the Libertarian party and became a Republican.  At age 78, he retired from Koch Industries "due to declining health."
Koch was listed in Forbes as the richest person in New York City, and was a highly-visible supporter of many cultural institutions there including Lincoln Center, the American Museum of Natural History, and the New York City Ballet.  After his diagnosis with prostate cancer, he donated more than $400 million to various organizations for medical research, including $185 million to MIT to establish the Institute for Integrative Cancer Research.

His Prostate Cancer
I do not have access to David Koch's medical records, but from information that has been released to the public, I can reach several conclusions:
•  Almost all North American men will develop prostate cancer if they live long enough, and the 15-year survival rate is 96 percent.  The average age of prostate cancer diagnosis is 66, and most patients will die from unrelated causes such as heart attacks or diabetes.  We know that Koch had the aggressive form of prostate cancer because he was diagnosed at the very young age of 52, and the cancer had already spread.
• All four of the Koch brothers have had prostate cancer (National Committee for Responsive Philanthropy, 2008).   A family history of prostate cancer is the strongest risk factor for the disease, and five to ten percent of prostate cancers appear to have genetic factors (Memorial Sloan Kettering Cancer Center, mskcc.org).  Various genes have been implicated, including the BRCA gene mutations that are also associated with breast cancer and ovarian cancer.  
• Koch had access to the best specialists and the most advanced treatments, and cost was no object.  Most men are limited to the treatment options that will be covered by their health insurance.  
Lifestyle Factors that Increase Risk for Prostate Cancer
Prostate cancer is diagnosed in one of every seven North American men. It is the second most frequently diagnosed cancer in men in the United States, after skin cancer, with 220,800 new cases and 27,540 deaths each year. Autopsy results of men who died from other causes show that almost 30 percent over age 50 have evidence of prostate cancer and more than 50 percent in their 70s already have the disease (Urol Clin North Am, 1989;16:635–655). 
There is some evidence that your lifestyle influences your risk for prostate cancer, and if you develop prostate cancer, it influences whether you will die from it.  Many studies suggest that prostate cancer, like heart attacks, strokes and diabetes, is a disease of inflammation, where your immune system attacks cells and damages the genetic DNA material to turn normal prostate cells into cancer cells.   Several studies associate smoking, being obese, and having a sedentary lifestyle with increased risk for prostate cancer.   Other risk factors are not firmly proven.
• Most risk factors for heart attacks are also risk factors for developing prostate cancer: high blood sugar, high insulin levels, high cholesterol, and diabetes or pre-diabetes (Horm Cancer, April, 2016;7(2):75-83). 
• Obesity is associated with increased death rate, more advanced-stage prostate cancer and higher Gleason scores (a measure of how malignant the prostate cancer cells look under a microscope), because it promotes the spread of the cancer once a man has it (Int J Oncol, March 2006;28(3):737-45).
• Storing excess fat in your belly markedly increases inflammation and thus increases risk for prostate cancer and chance for dying from prostate cancer, while adopting an anti-inflammatory lifestyle can help to prevent prostate cancer from spreading through your body (Cancer, May 2019; 125(16))
• High blood sugar (fasting sugar over 100) in men diagnosed with prostate cancer markedly increases risk of dying from prostate cancer (Prostate Cancer Prostatic Dis, June, 2013;16(2):204-8).
• Exercise is associated with reduced risk for both slow-growing and rapidly-growing prostate cancer that kills (Journal of Urology, November 2009;182(5):2226–2231).
• Men who participated most frequently in vigorous exercise had a 30 percent reduced risk of developing advanced prostate cancer and 25 percent reduced risk of dying from prostate cancer than those who exercised the least (European Urology, October 22, 2018).  Men in the highest group of intense exercisers had the equivalent of 25 minutes of running daily, with bicycling, swimming, heavy outdoor work, tennis or racquetball.

My Recommendations for Preventing and Treating Prostate Cancer
After a man is diagnosed with prostate cancer, the same risk factors associated with the disease also increase risk for prostate cancer progressing and being fatal.   Men diagnosed with prostate cancer are less likely to have the prostate cancer spread and kill them if they avoid smoking, maintain a healthy body weight, exercise regularly and intensely, and eat a high-plant diet (World J Urol, 2017 Jun; 35(6): 867–874).  
Most risk factors for heart attacks are also risk factors for prostate cancer (J Amer College of Cardiology: Cardiovascular Imaging, December, 2015).  It is likely that the most beneficial diet to prevent and treat prostate cancer is exactly the same as the diet recommended to prevent heart attacks: 
• eat lots of fruits, vegetables, seeds and nuts 
• restrict sugar-added foods and drinks and other refined carbohydrates
• restrict red meat and processed meats
• restrict fried foods and foods browned at high temperatures 
You should also try to exercise every day and lose excess weight if you are overweight.
May 3, 1940 – August 23, 2019