THE ART OF WATCHFUL WAITING: PULMONARY NODULES WITH EXTENDED SURVEILLANCE PERIODS IDENTIFIED AS PRIMARY LUNG MALIGNANCY IN VETERANS

Abstract

TOPIC: Lung Cancer TYPE: Original Investigations PURPOSE: Lung cancer screening has resulted in earlier, more accurate detection of pulmonary nodules, likely as a result of continued surveillance. Organizing care and timely follow up for patients with pulmonary nodules that require “watchful waiting” can be challenging. Comprehensive evaluation in a dedicated pulmonary nodule clinic (PNC) may help streamline further diagnostic workup and clinical care, while providing appropriate nodule risk assessment. In an effort to identify clinical characteristics and pulmonary nodule features that may indicate an increased risk for pre-neoplastic lesions, we reviewed a historical cohort of veterans in our single institution Veteran Health Affairs (VHA) medical center PNC. METHODS: We performed a retrospective cohort study of all patients seen in our PNC with a cancer diagnosis between January 2013 and February 2021. Patients with time to initial diagnosis of greater than 100 days, indicating ongoing surveillance, were included. Patients with metastatic disease, extra-pulmonary malignancy and time to diagnosis less than 100 days were excluded. Data collected included patient demographics, nodule characteristics, and cancer care outcomes including histological subtype, stage, and timeliness as well as method of diagnosis and treatment. RESULTS: We identified 430 patients with a new cancer diagnosis, the majority of which had metastatic disease, extra-pulmonary malignancy or were diagnosed within 100 days of nodule identification. Of those, 79 were enrolled in active surveillance, with an average age of 69 years. The majority of patients were men (94.9%) of which 51.9% were African American. The prevalence of previous smoking exposure was 90.0%, with 46.8% carrying a formal diagnosis of COPD. The pulmonary nodules in our cohort were primarily solid (54.4%) or mixed (22.8%). These were also either solitary (48.1%) or multiple i.e., 2-4 nodules (36.7%). The average longest dimension was around 18 mm. The most common methods of diagnosis were fiberoptic bronchoscopy (41.0%) and surgical resection (37.2%). The most frequent histological subtype was adenocarcinoma (68.4%) in which 91% of cases were treated with curative intent. The average time to diagnosis and treatment was 332 and 354 days, respectively. CONCLUSIONS: Pulmonary nodule risk assessment and surveillance remains paramount to ensure appropriate monitoring in patients with pre-malignant pulmonary nodules, or nodules not immediately actionable at time of identification. In patients enrolled in ongoing surveillance programs, we were able to identify characteristics that reflected an increased risk of malignancy for veterans, including current or previous exposure to smoking as well as previous hx of COPD, solid lesions and nodule size > 1 cm. Consistent with prior literature, the presence of 5+ pulmonary nodules conferred a lower risk of malignancy. In our cohort, the majority of nodules were diagnosed with bronchoscopy and the most frequent histological subtype was adenocarcinoma. CLINICAL IMPLICATIONS: Ongoing follow up in patients with risk factors for lung cancer without initial actionable nodules is imperative, as these nodules may progress to malignancy. Close monitoring may facilitate timely biopsy and earlier stage at diagnosis in this population.“This material is the result of work supported with resources and the use of facilities at the VA Maryland Health Care System, Baltimore, Maryland.” DISCLOSURES: No relevant relationships by Hatoon Abbas, source=Web Response No relevant relationships by Fahid Alghanim, source=Web Response No relevant relationships by Max An, source=Web Response No relevant relationships by Janaki Deepak, source=Web Response No relevant relationships by William Grier, source=Web Response No relevant relationships by Kevin Li, source=Web Response No relevant relationships by Avelino Verceles, source=Web Response