Interesting thread. Agree and disagree in part. The instruction to write like ordinary people do often means using words like “mestastasize” or “lame” and even “seminal” metaphorically. Most words are metaphorical extensions of earlier ones and we would be poorer if we declared them off limits.

As someone whose father died of cancer tragically early I have never read metaphorical “tumor” and been taken to that memory. Others might. But if we write anticipating the worst possible reaction from every reader we can’t follow the instruction to write in a plain, straightforward style.