Today is the American Cancer Society's Great American Smokeout - a day smokers can circle on their calendars as the day they quit smoking.While smoking has been most recognizably linked to lung cancer, quitting can also reduce your risk of bladder, head and neck, pancreatic and esophageal cancers - to name a few. And it's never too late to quit. On my flight back from meeting with the American Cancer Society this week, I sat next to a man who mentioned that his father was recently diagnosed with lung cancer. He mentioned his father had been a smoker, but had quit and started treatment. It's never too late to quit. There have been several studies showing patients who quit smoking during treatment have a better response than those who continue to smoke. Thankfully there are resources out there to help you to quit - and to help those you love to quit, including:National Cancer Institute SmokeFree.govCenters for Disease Control and PreventionAmerican Cancer SocietyFor those who continue to struggle with tobacco addiction, I thought it might be nice to hear from someone who has been there - President Obama. "The fact is, quitting smoking is hard. Believe me, I know."