Who should be screened?

In October, 2011, the National Comprehensive Cancer Network, a professional organization of the leading cancer centers in the United States, revised its guidelines on lung cancer screening.

NCCN gave its highest recommendation (with a Category 1 level of consensus agreement) to CT screening for current smokers and former smokers (who quit within the past 15 years) with a 30 pack year history (number of packs a day times the number of years of smoking) who are between the ages of 55 and 74;

Medicare Part B (Medical Insurance) covers lung cancer screenings with low dose computed tomography once each year if you meet all of these conditions:

  • You’re age 50-77.
  • You don’t have signs or symptoms of lung cancer (you’re asymptomatic).
  • You’re either a current smoker or you quit smoking within the last 15 years.
  • You have a tobacco smoking history of at least 20 “pack years” (an average of one pack (20 cigarettes) per day for 20 years).
  • You get an order from your doctor or other health care provider.

Your costs in Original Medicare

You pay nothing for the screening if your doctor or other health care provider accepts assignment

Things to know

Before your first lung cancer screening, you’ll need to schedule an appointment with your doctor or other health care provider to discuss the benefits and risks and decide if a screening is right for you.

More needs to be done to identify which smokers and former smokers are at highest risk, and which other groups may benefit from screening. But as more people at obvious high risk are screened, we can learn how to refine the screening process to make it safer, cheaper and more efficient.

To diagnose a nodule as a cancer, one needs to have biopsy of the nodule done, which can be accomplished by bronchoscopy.

Examination of the airways by bronchoscopy may show areas of tumor that can be biopsied for diagnosis by a pulmonologist. A tumor in the central areas of the lung or arising from the larger airways is accessible to sampling using this technique. Bronchoscopy may be performed using a rigid or a flexible fiber optic bronchoscope and can be performed in a same-day outpatient bronchoscopy suite. There are several ways bronchoscopy can be performed, as outlined below:

  • Simple bronchosopy
  • EBUS bronchoscopy
  • ENB bronchoscopy

ENB bronchoscopy : Patient education brochure
ENB bronchoscopy : Animation (large file)
Bronchoscopy : Patient Info

What are the risks involved?

Additional Testing

The goal of screening is to diagnose a cancer at an early stage when it is most treatable and curable. The step by step procedure for screening and determining whether suspicious findings are cancer or not cancer is called a protocol.

CT scanners can “see” minute lung abnormalities as small as a grain of rice.  If the scan picks up any findings suspicious for lung cancer, such as nodules over a certain size, or enlarged lymph nodes near the lung, or a lesion in the main airways, it is classified as a positive screen.

That does not mean that the suspicious findings are definitely cancer.  Many people, especially smokers or former smokers, will have a positive screen that could be caused by inflammation, scarring or other lung diseases rather than lung cancer.

About 10-20% of people screened for cancer by mammography, colonoscopy, PSA testing, or CT scans will have a positive screen which requires additional testing. Most will be false positives and only a small percentage will prove to be cancer.

On average about 12% of those screened at I-ELCAP sites will have a positive screen.  Positive scans averaged 25% at NLST sites which did not follow the more rigorous I-ELCAP protocol.

Positive screens will usually be followed by a second scan two or three months later to check for any change or increase in volume. Nodules larger than a grape found on the first scan, and those that appear to be growing on the second scan, may be further tested with a positron emission tomography (PET) scan to check for metabolic activity in the nodule that may indicate cancer.

A biopsy may be needed so that a small sample of tissue from the nodule can be examined under a microscope for cancer cells. Tissue is collected through a tube inserted down the windpipe (bronchoscopy) or with a needle through the chest wall (percutaneous fine-needle aspiration). Both procedures entail some risk of bleeding, infection or collapsed lung and should only be done by experienced doctors.

Even with all these precautions, some nodules – about 0. 5% – that are not cancerous may end up being removed by unnecessary surgery. All lung surgery carries significant risk and after effects.

Anxiety

Understandably many people who have suspicious findings (a positive scan) will experience anxiety during the evaluation period. But studies have shown that anxiety rapidly disappears when subsequent tests rule out cancer. For those whose cancers are confirmed, their anxiety must be weighed against the benefit of having the tumor diagnosed at a very early stage when treatment can be most successful.

It must be emphasized that CT-based lung cancer screening is not a test, but rather a process. The approximately 15% of individuals who have a solid lung nodule larger than five mm or a non-solid nodule larger than eight mm in diameter have further testing to determine if the individual with a nodule has a cancer (approximately 12%) or a benign nodule (approximately 88%) in the lung. The type of test, the order of tests and the time at which further testing should best be done is outlined in an organized plan called an algorithm or regimen.

The 88% of individuals who receive a negative report will logically be relieved of anxiety that might have been experienced before, during or after the performance of the CT scan. For this reason it is important to minimize the delay between performance of the scan and the generation of a report.

With respect to anxiety in screening, it should be understood that screened subjects start with a level of anxiety; that the reason for an individual enrolling in a screening program is anxiety about dying of cancer based upon information received in public health information or from a private physician.

There is good data from multiple studies indicating that research subjects tolerate anxiety experienced before and during cancer screening, as well as anxiety caused by positive screening results, and consider it to be a reasonable tradeoff for the benefit they derive from screening.

Radiation

Screening scans that check people who have no symptoms for lung cancer are given at low dose. In fact, screening scans are referred to as low dose scans. Follow-up scans that may have to be done to determine if any change or growth has occurred should be at the same low-dose.

Under the I-ELCAP protocol, the radiation from a CT screening scan has been reduced to about the same as a mammogram – from less than 1 to 1.5 millisieverts (mSv).  Similar, but slightly higher low dose scans were used in the NLST trial.

On average, people living in the United States are exposed to 3 mSv a year, and up to 10mSv at higher altitudes.

What if the nodule is cancerous?

Because most lung cancers found by screening are small size and early stage, treatment is most often surgery. However, surgery involves differing levels of risk (from less than 1% to as high as 5%) depending on the type of surgery (removal of a wedge section, a lobe or an entire lung) and the experience of the surgeon. Consequently, surgery should only be done by accredited thoracic surgeons with experience in lung cancers.

Emerging data suggests that screen-detected lung cancers can be routinely managed with less invasive video-assisted surgery (VATS) which can reduce the side effects, length of hospital stay and cost, and also significantly reduce the risk of mortality from the surgery. Some studies indicate that VATS can reduce the risk of surgical mortality to 0.1%.

Acknowledgement : http://www.screenforlungcancer.org/who-should-be-screened/#everyone, accessed 10/06/2012