I don't know how to respond to this study

It was a study of "more than 200 lung cancer patients".
Even I know that that number is really statistically insignificant.

BUT what I'm wondering about is the idea that quitting smoking after a cancer diagnosis is really a 'better' quality of life idea.

If they quit, they don't live any longer, but they don't deteriorate as fast.
BUT if they quit, then they're going through withdrawals while going through the chemo as well.

Specifically, their "performance status" -- a measure of patients' ability to care for themselves and function in daily life -- was generally higher, according to findings published in the medical journal Chest.

Patients who gave up cigarettes did not live appreciably longer than those who continued smoking, the study found, but the difference in quality of life highlights the importance of quitting even after lung cancer develops, according to the study authors.

"To the best of our knowledge, this is the first study to demonstrate a correlation between smoking cessation after diagnosis and performance status," write Dr. Sevin Baser and his colleagues.

Forgive me for being cynical, but doesn't the "ability to care for themselves and function in daily life" have something to do with the bottom line in terms of healthcare costs? You know, make them stop smoking while undergoing chemo and radiation, so they have to go through withdrawal at the sme time just to save a couple bucks?