Do you believe a cure for cancer should have been found by now?

First, understand that "cancer" is not one thing.  Cancer is many things, in many varieties, and lots of flavors.  Polio is a single disease; cancer is many diseases.  There will never be one cure for cancer.

Second, if tomorrow you figured out that drinking yak urine will cure cancer, then you will collapse a multi-billion dollar industry, putting thousands of people out of work, from donation officers to oncology nurses, to scientists.  If tomorrow you figured out that drinking yak urine will cure cancer, you would likely suddenly disappear.

They will never cure most forms of cancer as cancer is one of nature's built in kill switches!

If and when they think they have cured one form it will most likely evolve and treatments will become ineffective!

What for? cancer makes money

you noticed? the profit is the rule law

Why would anyone doubt wish an accomplished cancer researcher like Chris Rock?

Are you honestly so simple minded that you think comedians are an unimpeachable source of medical knowledge?   Cancer isn't like other diseases as its cause is our own bodies not doing their jobs correctly (so much for the intelligent design idea) and not reproducing cells correctly.   It may not have a "cure" in the traditional sense of the word.

As with everyone else that keeps posting variations of this same nonsense, you overlook all the obvious holes in the conspiracy theory that cancer is durable and that the mysterious "they" are holding back a cure.  The fact that research is going on in several countries and research is being shared in cancer research all across the globe.    Any research team that actually found a cure wouldn't be able to be silenced as it would guarantee them a place in medical history for all time. A cure couldn't possibly be silenced by any shadowy group because there is nothing they could do to silence all the people that would be involved in a group that had found a cure.   Also the fact that the rich and powerful still die if cancer proves that there is no hidden cure.

Cancer can be cured, but stupid people keep repeating "cancer cannot be cured" over and over... using definitions of "cure" that no one uses. You cannot "cure" a bacterial infection anymore than you can "cure" cancer... but you can treat it and have a large success rate with particular types of bacteria while having a low success rate with other types.

In a country with universal health care, a cure for all cancers would save a lot of money.

Imagine how much profit is made from 'treating' cancer: The drug companies are making a fortune! All that profit would vanish if there were a cure. Maximizing profits - through every possible means - is the underlying principle of the market economy! It is something of a shame that so many millions have to suffer so much to sustain the Stock Market.

As mentioned cancer is not one monolithic disease. Breast cancer is different from lung and is different from prostate cancer. Only the ignorant think it is and don't know the difference. 

Dead people don't buy things and its hard to make money off of dead people because they don't pay their bills regularly. There is no money in allowing people to die of cancer. The pharmaceutical industry is a very large industry that treats other conditions besides cancer. They are losing more money by people being dead than by being alive. If they were successfully treated for cancer then they will continue to be productive in the economy as consumers. 

Finding a cure for "cancer" would allow those people to continue to pay for many more drugs for the rest of their lives. They could make money off of heart disease, kidney disease and other many diseases out there. If they don't die of cancer then they will die of some other disease that pharmaceutical companies can make money on. There is no incentive in letting people die of cancer for the short term small money gain. Finding a cure for cancer would big a big money making drug for the drug companies. They would also make more money with them living and dying of other diseases that they can also make money on. 

The pharmaceutical industry is not hiding a cure nor are they killing people who claim to have a cure. It makes no logical sense at all. The "cancer industry" is a small fraction of the people who are sick in hospitals and in clinics. The bulk of the money being made is not dependent on cancer patients. That is true for hospitals and that is true for the pharmaceutical industry. 

With his vast knowledge of medicine, it's surprising that he makes a living telling jokes on stage.

I suppose it's a continuation of the comedy that some people are dumb enough to give his words about cancer research any weight.

By Chris Rock's logic (or lack thereof) pharmaceuticals would not create new and improved versions of their products. My wife had breast cancer at a fairly young age and has been in remission for 20+ years - when a decade before the life expectancy for the particular type cancer was less than a decade. SO if it was all about money they could have stopped anytime.