More frequent CT scans not linked to better outcomes after lung cancer surgery

Frequent postoperative surveillance imaging after lung cancer resection did not improve outcomes for patients with stage I non-small cell lung cancer, according to data published in Journal of the National Cancer Institute.

Guidelines from National Comprehensive Cancer Network, ASCO and other organizations recommend chest CT scans every 6 months for the first 2 to 3 years following lung resection. However, fewer scans could streamline care, lower costs and reduce anxiety associated with more frequent surveillance, researchers wrote.

“Our study builds on a growing body of evidence that more frequent surveillance does not improve outcomes in early-stage lung cancer,” Brendan T. Heiden, MD, MPHS, surgical resident and research fellow at Washington University School of Medicine in St. Louis, told Healio. “While this may be a somewhat surprising finding, similar observations have been found in other malignancies, including colon cancer. Although the potential benefits of more frequent surveillance may be intuitive — ie, earlier detection, more aggressive treatment, etc. — the potential harms of overly aggressive surveillance must also be considered.”

Background

Surgical resection is standard treatment for patients with early-stage NSCLC. However, approximately 20% to 50% of patients develop recurrence within 5 years. Consequently, surveillance has become a crucial part of postoperative care.

However, prior studies suggested more frequent postoperative surveillance imaging with CT may not improve outcomes for patients who undergo resection for stage I NSCLC.

Heiden and colleagues aimed to assess the relationship between surveillance frequency and RFS and OS.

Methodology

Researchers performed a retrospective cohort study of veterans with pathologic stage I NSCLC who underwent surgery between 2006 and 2016.

The cohort included 6,171 patients (median age, 67.5 years; 96.3% male) who underwent low-frequency surveillance (< 2 scans per year/every 6 to 12 months; n = 3,047) or high-frequency surveillance ( 2 scans per year/every 3 to 6 months; n = 3,124).

Researchers excluded patients who received more than four scans per year, as well as those who received only one scan over a 2-year period.

Results

After median follow-up of 7.3 years (range, 3.4-12.5), researchers determined 1,360 (22%) patients developed recurrence.

Results showed no association between high-frequency surveillance and longer RFS (adjusted HR = 0.93; 95% CI, 0.83-1.04) or OS (adjusted HR = 1.04; 95% CI, 0.96-1.12).

Factors associated with high-frequency surveillance included being a former smoker (vs. current, adjusted OR [aOR] = 1.18; 95% CI, 1.05-1.33), receiving a wedge resection (vs. lobectomy, aOR = 1.21; 95% CI, 1.05-1.39) and having follow-up with an oncologist (aOR = 1.58; 95% CI, 1.42-1.77).

Black individuals received low-frequency surveillance at a greater rate than white individuals (aOR = 0.64; 95% CI, 0.54-0.75).

Researchers reported median OS of 65.7 months (95% CI, 64-67.4) in the low-frequency group and 64.4 months (95% CI, 62.6-66.1) in the high-frequency group.

“These findings — in agreement with a growing body of other studies — suggest that post-resection lung cancer surveillance should occur at least annually, but that no clear benefit exists for more than semiannual surveillance within the first 2years after surgery for stage I disease,” Heiden told Healio.

Next steps

Researchers did not observe an association between more aggressive surveillance and improved cancer-specific outcomes, pointing toward the potential to adjust guidelines.

“[Although] additional prospective studies are needed to confirm these observations, future lung cancer treatment guidelines should consider less frequent surveillance — especially [for] low-risk groups, such as patients with early-stage disease,” Heiden told Healio.

For more information:

Brendan T. Heiden, MD, MPHS, can be reached at Washington University School of Medicine in St. Louis, 660 S. Euclid Ave., Campus Box 8234, St. Louis, MO 63110; email: bheiden@wustl.edu.