Wow...didn't live long after diagnosis.  There's a video clip of him announcing he had lung cancer (the hoarseness noted is a dark omen.  Indicates involvement of the recurrent laryngeal nerve near the trachea...suggesting advanced cancer at the time). 

One of the greats, to be sure.  Very eerie.  He was the last surviving member of the original anchors of World News Tonight, the others being Frank Reynolds and Max Robinson. 

Smoking.  Yep folks it does cause lung cancer (and  many other illnesses) but so many millions either refuse to believe it or think it will not affect them.   And...what is really scary is the very long latency in carcinogenic effect, especially with lung cancer.   Even after quitting, lung cancer can turn up 15-20 years later.    Jennings was a case in point (he returned to smoking after being quit for 20 years after 9/11), and George Harrison had a similar scenario.   However the statistical cancer risk is nearly at non-smoker level 10-15 years after quitting, but thereafter never goes quite as low as someone who had never smoked. 

QUIT NOW, and stay quit. 

Suggestions/thoughts:

1. The physical withdrawals can be easily quelled with a nicotine patch. This must be prescribed by a physician and followed.

2.  There are some medications which help if carefully monitored by a physician, notably Wellbutrin (Buproprion).

3. You must really want to quit (this is the most important step).

4. Rewards come early.  People feel enormously better within weeks. Cardiovascular system can improve as early as 6 weeks post quit, and can approach non-smoker in one year. 

Remember...SMOKING is a DRAG

Gene