Hello all, my case is in QA category of a hospital. Every month, there are around 500 questions which the customers submit to our website, and the director asks to publish all of the questions with the answer from the doctor.

If it still continues, there will be thousands of QA urls. However, there are a lot of QA urls with nearly the same content or question or title of question. Therefore, I am afraid that CANNIBALIZATION will take place. So how to solve it without causing harms to SEO? I got two ideas:

1. I supposed that noindex or cannonical tag to TOO MANY (for examples 500,000 QA urls) are BAD to SEO or not? Is there any public information from Google?
2. I will edit each of the QA urls to add internal links to the seo QA/post to transfer link juice and navigate Google bot, in order to avoid cannibalization.

Please note that,
Some of the QA urls will be kept it normally indexed since I also rank some keywords for them. Therefore, some SEO QA wil be kept indexed for ranking low competitive keywords (like questions...) and the multitle others will be NOINDEXED OR CANONICALED if I choose FIRST option.
My boss asks to publish all questions seperately because each situation of patient is quite different (despite that the main purpose is the same). If possible, I will combine, but I can not.