Lung Cancer Screening in Primary Care

The study “Results of Lung Cancer Screening in the Community” was conducted to address concerns regarding the generalizability of the National Lung Screening Trial (NLST) findings to community settings. The previous NLST study reported a 20% decrease in lung cancer mortality using lung cancer screening (LCS) in high risk patient populations. However, the NLST study utilized expert medical centers in the detection and treatment of lung cancer. This paper seeks to evaluate LCS in non-university, tertiary care, community settings.
Patients were recruited from a wide array of settings including non-university tertiary clinics, community medical centers, and free-standing imaging centers. Primary care physicians referred patients for screening, and shared decision making preceding a patient receiving a low-dose CT scan. All CT scans were categorized into 4 categories, with category 1-3 being negative, benign, or probably benign respectively. Category 4 scans, which were suspicious for lung cancer, were reviewed by a multidisciplinary thoracic disease conference. The conference included physicians from a variety of specialties including medical oncology, thoracic surgery, radiation oncology, and pulmonology. The group agreed that having a dedicated group of highly specialized physicians to review scans would be difficult to achieve in community settings, especially those with limited resources. Furthermore, patients with suspected lung cancer were scheduled to follow-up with thoracic specialists who were locally and nationally recognized. Additionally, almost all follow-up (99.9%) went through the study’s LCS coordinator. Thus, an LCS coordinator appeared essential for successful follow-up.
The demographics of patients in the study were 86% white, 44% were 55-64 years, 56% were 65-81 years, 50% male and female, 40% were former smokers, and 60% were current smokers. The authors stated their patient population group was more diverse than the LCS study (which reported 91% white). However, the group agreed that the difference was minimal and that there was little diversity as 86% of their patient population is white. The group agreed that data regarding insurance status, hospital setting (whether it was a community setting or not), and information regarding socioeconomic status would be beneficial. Furthermore, collecting and stratifying patients based on zip code would provide increased information on whether patients were in urban or rural areas.
Of the 4,666 initial referrals, 3,402 patients were included in the study. Reasons for excluding the 1,264 individuals were not reported. The group thought it could be concerning as patients may have been excluded due to factors such as lack of insurance or distance from CT scanners. Of the 3,402 patients included, 2,791 (82%) had enrolled or completed the LCS during the study period.
Of the patients included in the study, 500 patients required further imaging with 501 additional chest CT’s ordered. 176 patients underwent invasive interventions including 141 invasive diagnostic procedures and 85 surgeries. There were 12 diagnostic and 11 surgical complications reported. The most common diagnostic procedure complication was pneumothorax with 10 reported, and among the surgical complications, there were 2 deaths. However, adverse events were not correlated to the stage of lung cancer. Increased information would allow for better understanding of the risks as it would be expected that patients diagnosed at a higher stage of lung cancer experienced more adverse effects. A promising result was that no adverse events were reported with the initial CT scan.
Of the 2,791 patients enrolled in LCS, 95 were diagnosed with lung cancer with 67 patients diagnosed as early stage non-small cell lung cancer. An additional 16 cancers were diagnosed including renal, breast, and colon cancers. The group agreed the results of the screening were promising as 70% of lung cancers detected were in early stages allowing for more effective treatments and reduced mortality. However, healthcare system type of the patients was not reported. This information would be useful to determine if there was a marked difference in diagnosis rates depending on the patient’s healthcare systems.
The authors admit that the study may not be very generalizable as it was conducted in an integrated health care system (Providence St Joseph Health). In areas where the healthcare system is not integrated, such as in cities with competing healthcare systems, the results of LCS may be less than favorable. Furthermore, the study utilized locally and nationally recognized chest specialists in their thoracic oncology program. This further weakens the generalizability of the study as many healthcare systems, especially community programs, do not have the resources to employ a highly specialized team. The generalizability of the study is further limited as socioeconomic information of the patients were not included. Lower socioeconomic communities tend to have lower resources and difficulty following up due to a number of factors such as lack of insurance, inability to miss work, difficulty obtaining child care, inadequate transportation, and a long commute to healthcare which may alter the success of a LCS program. Additionally, the group agreed that a cost vs benefit analysis of the screening would be useful as an expensive screening with small benefit may be difficult to implement in financially struggling health centers.
The conclusion of the paper that LCS in community settings can be successfully performed was not completely supported by the data. The data does not stratify the patient pools based on location of initial referral, or differentiate the results based on whether the patient was located in a community or another hospital system. Therefore, the proportion of patients from community settings was unknown. The demographic information of the patients is limited, and it is unknown if patients identified with lung cancer were from community centers. The group acknowledges that the data may have been removed from the paper in interest of cohesiveness and space, and overall thought the study was conducted to a high standard.