CT screening for lung cancer: Frequency of enlarged adrenal glands identified in baseline and annual repeat rounds

Abstract

Objectives: To determine the frequency of adrenal enlargement of participants in a CT-screening program for lung cancer and demonstrate the progression during follow-up, separately for baseline and annual repeat rounds.

Materials and methods: HIPAA-compliant informed consent was obtained in 4,776 participants. The adrenal gland was defined as enlarged if it measured ≥6 mm at its largest diameter. Logistic regression analyses were performed.

Results: At baseline, 202 (4 %) of 4,776 participants had adrenal enlargement. Significant factors were age (OR = 1.4, 95 % CI: 1.2-1.7) and current smoker (OR = 1.8, 95 % CI: 1.3-2.4). Follow-up 7-18 months after baseline for 133 cases with adrenal enlargement <40 mm showed it decreased or was stable in 85 (64 %), and increased by <10 mm in 48 (36 %). Five (0.04 %) cases of adrenal enlargement were newly identified, none increased beyond 40 mm on follow-up. Adrenal enlargement was a significant predictor of a subsequent diagnosis of lung cancer (OR = 2.0, 95 % CI: 1.2-3.4).

Conclusion: Participants with adrenal enlargement <40 mm identified at baseline and on repeat screening could be reasonably assessed on subsequent annual screening. Adrenal enlargement increased with increasing pack-years of smoking. Adrenal enlargement was an independent predictor of a subsequent diagnosis of lung cancer.

Key points: • Adrenal enlargement was seen in 4 % of participants at baseline screening. • Age and currently smoking were significantly associated with adrenal enlargement. • 0.04 % of participants were newly identified with adrenal enlargement. • Annual follow-up for adrenal enlargement <40 mm was appropriate. • Adrenal enlargement was an independent predictor of a diagnosis of lung cancer.

Keywords: Adrenal enlargement; Adrenal masses; CT screening; Current smokers; Lung cancer.