UC San Diego Health Sciences News

Smoking not

Smoking causes roughly one-third of all cancer deaths and 87 percent of all lung cancer fatalities. An estimated 160,000 Americans this year will die of lung cancer, more than colon, breast and prostate cancer deaths combined.

Despite this harsh reality, a new study out of the University of Michigan reports that somewhere between 50 and 83 percent of cancer patients who smoke don’t stop after their diagnosis. For cancer patients who do try quit on their own, the relapse rate can be as high as 85 percent.

The downsides of continuing to smoke after a cancer diagnosis are many: It hampers treatment. It increases recurrence of the disease. It decreases survival.

The question, then, is why so many smokers with cancer keep smoking.

Study author Sonia Duffy said it appears to be a numbers game. Smokers with cancer must overcome a lot of hurdles to successfully quit. These include nicotine addiction, associated issues involving health, mental and physical, and healthcare access. These cancer patients, Duffy added, often suffer from sleep deprivation, poor nutrition, lack of confidence in being able to quit and poor socioeconomic status. Often, the grueling demands of their cancer treatments leave them little time or energy for quit-smoking programs.

Depression is another big issue: Among cancer patients, depression rates can be as high as 58 percent compared to 10 percent in the general population.

Perhaps the most surprising finding in the study is that only 56 percent of family physicians urge their cancer patients to quit smoking, according to the Michigan study. Most oncologists do advocate quitting, Duffy said, but their main focus is upon treating the cancer, not associated issues.

It’s not a pretty picture, but then neither are the physical effects of smoking. The image above bears witness. It depicts lung tissue from a patient who had panacinar emphysema, a form of emphysema in which the lungs’ multitudinous alveoli or air sacs are destroyed over time, reducing the lungs’ capacity to take in and process oxygen. Smoking is the primary cause of panacinar emphysema, though it can also be the result of a genetic disorder called alpha-1 antitrypsin deficiency.

In this image, the alveoli have generally collapsed, creating a darkened, non-functional mush of dead tissue. The only vessels that remain open are arteries, veins and bronchioles, the larger pathways that funnel air to alveoli.