Lung Cancer Screening?

More people in the US die from lung cancer than any other cancer. Yup, it’s true. Our number one cancer killer is not breast or prostate cancer (#2, for women and men, respectively), not colon cancer (#3 for both) or skin cancer (doesn’t even make the top ten). In fact, the lung cancer mortality rate (the number of deaths per 100,000 people) is more than double the rate of the number two cancer killers. Just to give you an idea, in the US in 2009, there were 205,974  people diagnosed with lung cancer: 110,000 men and over 95,000 women. In that same year, 158,000 people died of lung cancer.

This means that most of us know someone who has had lung cancer. Don’t you?

When I was thirteen, my godfather (a career bus driver for Golden Gate Transit and gifted salmon fisherman) died just three months after being diagnosed with lung cancer. He was a lifelong smoker. Almost ten years later, my mother’s mentor (a grandmother-figure for me) also died less than six months after being diagnosed. She was a prolific artist and a retired kindergarten teacher; she had been a smoker for over 40 years but had quit about 15 years before her diagnosis.

As a family doctor, I see lung cancer with some frequency. Just last week,  I was working at the hospital and a healthy 50-ish woman came in after several months of feeling short of breath. She, too, had been a long-time cigarette smoker but had quit eight years ago when her own mother died of lung cancer. Because she had no health insurance (cue for another post: uninsured in America),  her family doctor tried to avoid an expensive evaluation (a single chest radiograph can cost over $150), treated her for bronchitis, pneumonia, then COPD (chronic lung disease from smoking). Eventually, an x-ray showed an unmistakable lung cancer.

Last year, one of my favorite patients, a garrulous retired umpire and amateur historian who always had at least one joke for me during our clinic visits (usually clean jokes but occasionally a little off-color) passed away from metastatic lung cancer. Amazingly, he survived for more than 18 months after his diagnosis and was able to get a few things ‘in order’ before he died. Most important to him was  to donate his body to a medical school so that medical students could learn from him . And he did it! (cue another post: body donation)

And, in the plus column of cancer advances, also last year, one of my dearest patients was actually declared ‘cancer free’ from his inoperable lung cancer five years after he went through intensive chemotherapy and radiation.

Unfortunately, most everyone you or I have ever known with lung cancer has been really quite ill by the time they were diagnosed. (Studies show that 75% of people with lung cancer present ill with metastatic and/or incurable disease at time of diagnosis). And, unlike breast cancer (though, mammograms aren’t perfect-- another future post: mammograms) and cervical cancer (pap smears and HPV testing have revolutionized us: pap smears), historically we just haven’t had good ways to screen ‘healthy people’ for lung cancer.

Well, the new news in lung cancer is maybe times are changin’.  

We may actually start screening our highest risk patients for lung cancer. Soon.

Just to be clear remember that a SCREENING test is a test of totally well person to ‘screen’ for a disease, while a DIAGNOSTIC test is as test on a patient who comes in with symptoms (e.g. cough, weight loss, etc).

Just this week the United States Preventive Task Force (USPSTF-- you should know that  the USPSTF is one of my favorite go-to bible-sources. I consider them one of the most unbiased, non-partial, uninfluenced by finances official body who makes recommendations about various medical conditions) put out a DRAFT new recommendation, updated from their previous recs in 2004, in support of annual lung cancer screening, using annual low dose CT scans, for people ages 55-79 who have at least a 30 pack year smoking history (and have smoked in the past 15 years).

Why did they make this change?

There have been seven studies in the last 15 years looking at low dose CT scan screening for lung cancer. The largest, the National Lung Screening Trial (NLST) published in 2011, looked at 53,454 current or former smokers. This study showed that patients getting a low-dose helical CT scans  every year for three years had a 20% lower risk of dying from lung cancer  (and  a 6.7% lower risk of dying from all causes) than people who received chest X-rays every year. They reported that we need to screen 320 patients one time with a CT scan to prevent one lung cancer death. (This is called the NNT) Of note, three smaller European studies (all with under 5,000 patients) patients found no benefit to screening.

What does this mean for me?

Well first, off, I will stick with a hard party line. If you don’t smoke, don’t start. If you do, then quit. Now. Then you hardly have to worry about this stuff! However, if you are between the ages of 55 to 79 and are either a current smoker (for at least 30 pack years) or quit in the last 15 years, you might want to talk to your primary care doctor about getting a low dose CT scan. Remember, there is still radiation involved and no test is without risk The good news from a financial perspective is that the current ACA (Obamacare) agrees to cover All Grade A and B recommendations, so this study should be covered if you have health insurance (including Medicare, CMSP, MediCal, etc)

What are the risks?

Radiation exposure: radiation associated with one low dose CT ranged from 0.61 to 1.50 mSv

False positives: remember not every test result that comes back bad means there is something bad actually happening. This is one of the trickiest areas of medicine because people really want to trust tests, but tests are not perfect.

False reassurance: Screening tests don't necessarily pick up every cancer either, so just because your CT scan was normal doesn't mean you don't have cancer (yup, that's an uncomfortable one to swallow).

Overdiagnosis: Just like with other types of cancers (and even less worrisome illnesses like herpes or strep throat), the more we screen for the things, the more we find. We may find that some lung cancers picked up screening would have never progressed to make anyone sick, but it would be impossible to tease that out.

How does this change the game?

In two major ways: 1) If the USPSTF rating remains at B, then lung cancer screening will join other common cancer screenings (like breast and colon cancer screening) as covered entities under the Affordable Care Act (i.e. it will be covered by your health insurance) and 2) Smokers are going to get quite a few CT scans in their lifetime.

So, I have a better idea, how about you just put out that cigarette and call it quits, keep yourself out of this risk pool and call your mom?

Reference:

http://www.cdc.gov/cancer/lung/statistics/

http://sonoma.networkofcare.org/ph/indicator_detail.aspx?id=lung_canc_in&c=7

http://apps.nccd.cdc.gov/uscs/toptencancers.aspx

http://annals.org/article.aspx?articleid=1721248