So - the first source there has no abstract available - did you look at it? Why include it when we don’t know what it says.

The second source - what exactly did you take away from that? What’s your understanding of the phrase ‘surrogate end-point’?

The third source doesn’t say chemotherapy is ineffective - it’s saying that it is very unpleasant and there needs to be additional research on reducing general toxicity and therefore effectiveness

The forth source is saying chemotherapy is expensive. No abstract available.

At this point I give up the will to live - you aren’t providing us with sources that demostrate your original claim that “drugs have never been proven effective at improving survival” - you’re just throwing vaguely related links at us in the hope taht we won’t look too carefully.