The Wall Street Journal has an article about the War on Cancer act, which was passed 40 years ago.
From the CDC, the amount people who survive cancer after being diagnosed has tripled over the last 30 years:
From the same report, death rates from cancer have been falling for all major demographics, for most of the major types of cancer.
Furthermore, you could posit that cancer treatments are doing a better job at maintaining quality of life after diagnosis. More and more treatments take place in a patients home, or in a social setting, and less often in a lab or hospital.
From a report from the National Institute of Health, lost years of productivity are dis-proportionately focused in lung cancer patients. This is encouraging in a backhanded way, since lung cancer is mostly the result of smoking, which is a lifestyle issue more than a medical issue.
Overall, these are good reasons to be optimistic. There aren’t too many examples of unsolved problems in cancer treatments. The more relevant issue is why it occurs so much in the first place.