Some cancers have long-established screening guidelines for early detection, but not lung cancer, the leading cause of cancer-related deaths in the United States. Now, for heavy smokers at least, screening with low dose spiral CT (LDCT) scans has been shown to lower the risk of dying of lung cancer by 20 percent when compared to screening with chest X- rays.
While some cancers have long-established screening guidelines for early detection, lung cancer, the leading cause of cancer-related deaths in the United States, had no recommendations until recently.
Now, for heavy smokers at least, we have news: Screening with LDCT scans lowered the risk of dying from lung cancer by 20 percent when compared to screening with chest
The National Lung Screening Trial (NLST) is important because it’s the first time we’ve been able to establish that a screening test for lung cancer can save lives.
Lung cancer remains the leading cause of cancer-related mortality in the United States. It’s estimated about a quarter of a million people will be diagnosed this year, and there will be about 160,000 deaths.
The landmark screening study involved more than 50,000 current and former heavy smokers (people who smoked the equivalent of a pack of cigarettes a day for 30 years and were age 55 to 74). At the start of the study, they were randomly assigned to receive a LDCT or chest X-ray.
Participants were screened annually for three years and then were followed for five years after that. The results showed 354 lung cancer deaths among those who had been screened with CT scans vs. 442 deaths among those who had chest X-rays.
The National Comprehensive Cancer Network and the American Society of Clinical Oncology have provided guidelines for screening for high-risk individuals, but there is much about the NLST study that needs to be analyzed before LDCT scanning to detect lung cancer is more widely recommended. For example, risks associated with LDCT scanning need to be considered. These include:
False positives. The increased sensitivity of CT scans can lead to false positive results—suspecting cancer where there is none, which can lead to invasive procedures, necessary
surgery, and anxiety.
Exposure to radiation. There may be an increased risk of developing cancer from the radiation that’s absorbed from CT scanning. Although this risk is small, you have to weigh it vs. the benefit.
Screening mammograms for breast cancer, pap smears for cervical cancer, and
colonoscopies for colon cancers help in detecting these diseases at early stages and provide a curative treatment. Screening guidelines for above mentioned cancers, have been widely adopted as the standard of care.
It remains to be seen whether the NLST results will lead to changes in screening
guidelines for lung cancer. Although, the NLST trial suggests benefits of screening for lung cancer with CT scans among heavy smokers, it’s still early to recommend anything other than this limited use.
If you’re a heavy smoker—or used to be one—discuss the potential benefits and risks
of lung LDCT scan screening with your doctor given the information we now have. This NLST study has provided considerable optimism for early detection of lung cancer, but smoking is still the primary cause of lung cancer. Education and helping smokers to quit are the best ways to prevent lung cancer.