Dr Mark Socinski on the Need for Lung Cancer Screening in Eligible Patients

Mark A. Socinski, MD, executive director at AdventHealth Cancer Institute, discusses the importance of lung cancer screening in eligible patients, including the need for primary care providers to ensure screening is being implemented.

Transcript

Why is screening so important for eligible individuals, and which patients should be screened?

Lung cancer has been the leading cause of cancer-related deaths for decades. So for the past decade or so, we've had evidence from 2 randomized clinical trials looking at low-dose spiral CT scanning in high-risk patients. The high-risk patients were essentially patients between the ages of 50 and 80—one guideline uses the age of 77, so close to 80—and you have to have a certain pack-year exposure to cigarette smoking, and you have to have smoked within the past 15 years, because that defines a high-risk group. The pack-year initially was 30 pack-years. How we calculate pack-years is if you smoked 1 pack a day for 30 years, that would be a 30 pack-year exposure. If you smoked 2 packs a day for 30 years, that would be a 60 pack-year exposure.

We do know from early research on cigarette smoking that there's kind of a dose-response effect. The more you smoke, the more likely you are to develop lung cancer, although the vast majority of patients who smoke will not develop lung cancer but may develop other problems like heart disease and COPD and all that stuff.

The original studies compared the low-dose spiral CT strategy to chest x-ray. Even though chest x-ray had never been established as a standard screening problem, the trial was designed to do something on the control arm. And it showed a significant reduction in lung cancer mortality, about a 20% risk in those high-risk patients. It really mainly detected cancer at an earlier stage where it was much more highly curable. Obviously, the cure rate of cancer is inversely related to the stage. If you have stage I disease, you're much more likely to be cured than if you have stage IV disease. Subsequent trials have validated this.

The interesting thing also is all-cause mortality. Not only was lung cancer mortality decreased, but all-cause mortality was decreased. The thinking there is there were other problems that were detected on the CT scan. First and foremost was coronary calcifications, suggesting that they detected and diagnosed significant cardiovascular heart disease, where one could intervene before you had some sort of catastrophic cardiac event. And again, the all-cause mortality was decreased.

So, the the spiral CT scan strategy is real in terms of helping people. Now, one of the issues that we have is that it is woefully underpracticed in the United States. The number of patients who are not getting screened that would fit into the categories that I've mentioned previously—50 years of age or older. They've lowered the pack-year exposure to 20 pack-years now, based on some more recent data. It's not happening, and I really don't understand, from my perspective as a lung cancer doctor, why that shouldn't be. But I've heard primary care doctors—because this is really a primary care issue. This is not something we deal with as a cancer doctor, because these people don't have cancer.

The other important point about the screening trials that's important to understand is patients have to be asymptomatic. So obviously, if you have a cough or chest pain or something like that, where you have a symptom, then it's not screening, it's diagnostic at that point. So they're asymptomatic, and if you detect a small cancer when the patient is asymptomatic, the studies have clearly shown it's much more likely to be stage I disease where surgery is highly curable.

From the primary care perspective, they have failed to broadly endorse this. I think national organizations broadly endorse it, however, making it work on Main Street USA. It shouldn't be for reimbursement reasons—it's endorsed by CMS in Medicare patients, which obviously are the older population—but it clearly is a screening procedure that does as much to reduce lung cancer mortality as mammograms and colonoscopies and all the other screening things that we do—pap smears for cervical cancer, and that sort of thing. So it should be part of the routine screening aspect of it if you fit into those high-risk categories.