Never heard of that one before. I am so glad I did quit for so many reasons, wish you all the luck in the world, it can be done!!!

@kowalski That doesn't sound like anything I'd come across. I just googled and found the attached reasons why smoking hampers recovery. It's from Cleveland Clinic but I'm pretty sure I'd seen the same either on Mayo's site or cancer.org when I was going through it. https://health.clevelandclinic.org/smoking-cancer-diagnosis-quit-now/

Quitting is hard. But your body will thank you, regardless of any “jolt” to your system. We don’t like to hear that we are addicted, but anyone who’s tried to quit has learned how addictive tobacco is.
Not quitting for fear of a jolt is an easy rationalization to keep smoking. Don’t believe it.
You’ve got this. Go for the jolt!

@kowalski, there are many approaches to successfully quite smoking. For some a gradual decrease helps, especially with aids like nicotine patches or quit medications. Others find cold turkey works for them. The website https://www.becomeanex.org/ in partnership with the Mayo Clinic Nicotine Dependence Center (NDC) offers support and resources.

Here's some information and a video specific to your questions:
Why it’s so important to quit smoking when you have cancer https://www.cancercareontario.ca/en/blog/Why%20it%E2%80%99s%20so%20important%20to%20quit%20smoking%20when%20you%20have%20cancer