Does quitting smoking help after a lung cancer diagnosis?

Question

Hello doctor,

My grandfather is 78 and was diagnosed with lung cancer, stage 3A squamous cell carcinoma, about a year ago. He smoked from his early 20s until about age 70 and always said he would quit eventually, but never really did until his health forced him.

After the lung cancer diagnosis was confirmed, he finally stopped completely. But now, when anyone brings up quitting, he just shrugs and says it does not matter now; the damage is already done.

His oncologist has him on stereotactic radiotherapy since surgery was not an option due to his COPD - FEV1 at 38 %. From a purely medical perspective, is he right?

Does quitting smoking at 78, after a lifetime of smoking and a lung cancer diagnosis, actually have any measurable clinical benefit? I ask because part of me wants to validate what he feels, and part of me wants to give him a real reason to stay stopped. His mood has been very low, and I do not want to give him false hope, but I also do not want him to feel like nothing he does matters anymore.

Please help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query.

I understand why he feels that way. Many patients in his situation say something similar. It often comes from a sense that the damage is already done. But medically, that is not quite true. Even now, stopping smoking still makes a meaningful difference.

At this stage, the focus is not only on treating the disease but also on how comfortably he can live day to day. Continuing to smoke would worsen his breathing, increase the risk of flare-ups of COPD (chronic obstructive pulmonary disease, a progressive, incurable lung disease that restricts airflow, making it difficult to breathe), and add to his overall discomfort. Since his lung function is already reduced, even a small additional strain from smoking can noticeably increase breathlessness.

In practice, there is a clear difference between patients who continue smoking and those who stop. Those who quit usually tolerate treatments like radiotherapy better, have fewer complications such as infections or persistent cough, and tend to feel more stable overall. It may not change everything, but it can make a real difference in how he feels.

There is also evidence that quitting smoking after a lung cancer diagnosis can improve outcomes, including survival in some cases. More importantly, it reduces day-to-day suffering, and that is very significant.

What he is expressing is more emotional than medical. He may feel that nothing will change the situation now. Instead of correcting him directly, it often helps to frame it differently. You could tell him that by not smoking, he is helping himself breathe easier and go through treatment with less difficulty. That tends to connect better than talking about long-term benefits.

He has already taken an important step by stopping. That still matters, even now.

I hope this answers your query.

Please let me know if I can assist you further.

Thank you.