Lung cancer remains the leading cause of cancer-related deaths in the nation. Last year alone, lung cancer claimed the lives of 142,670 people, roughly 27% of cancer deaths overall. And the overall five-year survival rate remains horribly low (~19%) despite the relatively recent development of targeted lung cancer treatments for driver mutations (EGFR, ALK, ROS-1 etc.). Much of the mortality arises due to the fact that most lung cancers are detected at a late stage and not amenable to curative treatments (surgery or radiation). Typically, lung cancer will not present with symptoms such as chronic cough, chest wall pain, hemoptysis or recurrent pneumonia until the disease is at stage IIIB/IV. Even screening with standard chest X-ray can miss up to 85% of early stage lung cancers.
In 2011, the National Lung Cancer Screening Trial showed that early detection is possible with low-dose chest CT (LDCT) in appropriately chosen patients. In this study, a total of 53,454 patients age 55 to 74 with a minimum 30 pack year history of smoking were enrolled starting in 2002 and at 33 centers across the US and followed for five years. A 20% reduction in lung cancer specific mortality was observed compared with chest X-ray alone in this trial. The reason for this significant improvement in survival is that screening with LDCT shifts the stage of diagnosis from late (stage III/IV) and poor prognosis to early (stage I/II) with good prognosis. In 2014, the United States Preventative Services Task Force (USPSTF) recommended annual LDCT for high risk individuals, and in 2015 these scans were approved for coverage by CMS. Recently, the USPSTF recommended annual screening for high-risk patients up to 80 years of age.
CMS Requirements for LDCT:
- Be 55–77 years of age.
- Be asymptomatic (no signs or symptoms of lung cancer).
- Have a tobacco smoking history of at least 30 pack-years (one pack-year = smoking one pack per day for one year; 1 pack = 20 cigarettes).
- Be a current smoker or one who has quit smoking within the last 15 years.
- Receive a written order for lung cancer screening with LDCT that meets the requirements described in the NCD.
Of course, one of the requirements for being screened is that the patient should be medically able to receive some sort of therapy should they be found to have a lung cancer. Given the complexities of new targeted oncologic treatments, targeted radiation treatments and minimally invasive thoracic surgery including robotic resections, the decision as to whether a patient is a treatment candidate may be quite challenging and may require referral to one or more of these specialties.
Also, one of the problems with LDCT for lung cancer screening is that the number of benign lung nodules identified far outnumbers the lung cancers that are seen. As such, part of the decision making with newly seen lung nodules is what to do next. This can be a complex decision and is usually based on many parameters including size, location, growth, shape and characteristics of the lung nodule in question as well as patient smoking history, family history, lung function, etc.
In fact, many institutions, including Northside Hospital, are creating specific teams made up of pulmonologists, medical and radiation oncologists, radiologists, pathologists and thoracic surgeons to not only review LDCT scans but also make recommendations and chose any interventions or further studies that may be needed. In this way, we try to avoid potentially unnecessary, costly or potentially harmful further diagnostic procedures and interventions.
In summary, lung cancer screening is not just a low-dose CT scan, but is in fact a process involving multiple specialists and other diagnostic modalities to both identify and treat lung cancer and to avoid potentially unnecessary tests or procedures. When all this works together, we can improve our patients’ lives by helping them beat lung cancer.
