system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we spend billions and billions of dollars on cancer research, and still use Chemotherapy as the most widely used treatment.

After having people come to my door asking for support in Cancer Research, I asked them how much further we've come in the last ten years, and they couldn't tell me.  And they said that Chemotherapy is still the most widely used treatment in America for Cancer.  After having multiple family members who have died from Cancer after going through Chemo, I am just curious how effective Chemo is against Cancer cells, and where is all the money going that we donate if it's not making any widely known progress.
gpt
Cancer is a broad spectrum of diseases that involve uncontrolled growth or production from your own cells.  As broad a term as cancer is, chemo might be even broader.  Chemo is medication that kills cells or targets them for killing, but does so preferentially to cancer cells than non-cancer cells.  
  
Cancer research and effective chemo is making a lot of progress, as pretty much everyone on here is saying.  Money for cancer research goes toward staffing cancer research centers/hospitals, testing chemo drugs, and testing cancer screening strategies, just to name a few things.  There are MANY cancers that we have developed a very effective chemo regimen for.  Testicular cancer is one that we are able to very effectively treat with chemo.  More recently, a specialized chemo drug for Her2 positive breast cancer has been developed.  This form of breast cancer used to be a death sentence, now it's one of the more favorable breast cancer diagnoses because of the efficacy of our available chemo.  
  
You'll never turn on the news to a headline of "chemotherapy stops all cancer all at once."  What's unfortunate is that the many small victories in cancer research don't receive the attention that they should, leaving the lay person to believe that there hasn't been progress.