Lung Cancer Screening: A new standard of care?
Jacques P. Fontaine, MD, FACS
Thoracic Surgeon, Moffitt Cancer Center
Lung cancer is not the most common cancer in men. Prostate cancer is. And lung cancer is not the most common cancer in women. Breast cancer is. However, lung cancer kills more American men than prostate cancer and more American women than breast cancer, colon cancer and cervical cancer combined. Lung cancer is the leading cause of cancer-related deaths in the United States. And while the incidence of smoking is slowly decreasing, the incidence of lung cancer continues to rise.
The 5-year overall survival rate for lung cancer is 16 percent compared to 97 percent for prostate cancer and 84 percent for breast cancer. There are two reasons for this. First, the tumor biology is very aggressive. Second, most lung cancers are diagnosed in advanced stages where prognosis is very poor. The great majorities of early stage lung cancers are asymptomatic and discovered incidentally. The prognosis of very early stage, asymptomatic lung cancers is comparable to that of prostate, breast and colon cancers. Certainly, smoking cessation and prevention programs aimed at adolescents and young adults is the best long-term method to decrease the impact of this cancer on our society. However, the most practical and immediate method to improve the prognosis for our lung cancer patients is to diagnose them earlier when the chance of a cure is much better. Renewed interest has thus emerged in the significance of lung cancer screening programs.
Successful government-funded screening programs for prostate cancer, breast cancer, colon cancer and cervical cancer have been in place for years. Until recently there were no screening programs for lung cancer, the number one cancer killer in America.
Previous lung cancer screening programs using chest X-rays were ineffective. To determine whether CT scans were more sensitive and could be an effective screening tool, the National Cancer Institute (NCI) funded a large multicenter, prospective randomized trial, which enrolled 53,456 patients between 2002 and 2004. The fact that so many patients were enrolled so quickly is a testament to patients’ willingness to enroll in lung cancer screening programs. Patients in this study were considered at high risk for developing lung cancer and consisted of asymptomatic men and women between the ages of 55 and 74 who had a 30 pack-year history of smoking. The patients were randomized to an annual CXR or to an annual CT Scan.
A “positive” screen was a CT Scan demonstrating a 4mm non-calcified nodule. An astounding 24 percent of patients were found to have a positive CT Scan. Various investigational algorithms for these pulmonary nodules were used to determine which nodules were suspicious enough to warrant a biopsy. These “work-up” algorithms, which included the use of PET Scans and repeat interval CT Scans, were not standardized and therefore more realistic of generalized medical practice. Using proper work-up algorithms, only 8 percent of patients found to have pulmonary nodules were deemed suspicious enough to warrant a biopsy. This represented less than 2 percent of the screened population. Of the patients who did undergo a biopsy, 53 percent were found to have a lung cancer, and the majority of the time (63 percent) it was an early Stage I cancer. Due to the fact that so many of these lung cancers were detected at an early stage, this translated to a 20 percent reduction in mortality. The cost of having lung cancer screening covered by commercial healthcare insurance plans would be less than $1 per month for policy holders – far cheaper than breast cancer screening at about $3 per month. In terms of cost effectiveness, the cost per life-year saved would be below $19,000. This compares favorably to cost per life-year saved in breast ($31,000 - $52,000), colon ($19,000 - $29,000) and cervical ($50,000 - $75,000) cancers.
On the other hand, these results also highlight the fact that 47 percent of patients who underwent a biopsy did not end up having a lung cancer and therefore underwent an “unnecessary” biopsy. We can be reassured, however, that patients with pulmonary nodules deemed suspicious enough to require a biopsy were at very low risk of being harmed by a “negative” biopsy, since the complication rate was extremely low (0.05 percent) due to the minimally invasive techniques used (bronchoscopy, percutaneous needle or thoracoscopy). Avoiding unnecessary scans or biopsies is a top priority for multidisciplinary teams specializing in lung cancer and using rigorous algorithms. With proper use of algorithms, 92 percent of patients found to have a pulmonary nodule on CT screening avoided a biopsy, and none developed a lung cancer from a false negative screen.
CT Scan screening for lung cancer not only impacts survival from the disease, but also the way we treat it. Surgical resection remains the best treatment modality with the highest cure rate for early stage lung cancer. Because lung cancers are typically diagnosed in advanced stages, however, even for those patients where lung resection is an option, the cancers are often too large for minimally invasive, lung-sparing surgical techniques. Thus, another major advantage derived from CT Scan screening for lung cancer is the fact that the majority of these lung cancers are discovered at an early stage when they measure less than 2cm. These small tumors are ideally resected using minimally invasive techniques of thoracoscopy (VATS) or robotic surgery, rather than using a more traditional and invasive thoracotomy.
The costs of lung cancer screening are already covered by medical insurance carriers in Japan, and some third-party carriers in the United States are in the process of approving coverage for this screening modality. Nonetheless, lung cancer screening programs are already being offered throughout the country with an out-of-pocket patient cost of up to $350. The radiation dose from a screening CT is similar to that of a screening mammogram and 10 times lower than a regular diagnostic CT scan of the chest.
Moffitt Cancer Center offers lung cancer screening, which includes a consultation with our specialized multidisciplinary team. Our team treats more lung cancer patients than any other institution in Florida. Over 70 percent of our lung cancer resections are performed using minimally invasive techniques, including robotic lung sparing surgery, with results superior to the national average. In addition, our surgical team has performed the most robotic lung surgeries in the state.