Aortic Aneurysm Natural Progression is Not Influenced by Concomitant Malignancy and Chemotherapy

Abstract

Aortic aneurysms occur concomitantly with malignancy in approximately 1.0-17.0% of patients. There is little published information regarding the effects of subsequent oncological therapies on aortic aneurysm growth. The aim of this study was to determine the effects of chemoradiation therapies on the natural progression of small abdominal aortic aneurysm (AAA), thoracic aortic aneurysm, and thoracoabdominal aortic aneurysm. Patients with aortic aneurysms with and without malignancy between 2005 and 2017 were identified within institutional databases using Current Procedural Terminology and International Classification of Disease codes. Inclusion criteria included complete chemotherapy documentation, a minimum of 3 multiplanar axial/coronal imaging or ultrasonography before, during, and after receiving therapy or 2 studies for patients without malignancy. Propensity matching, Cox and linear regression, and Kaplan-Meier survival analyses were performed. A total of 159 (172 aneurysms) patients with malignancy and 127 (149 aneurysms) patients without malignancy were included. Average patient demographics were 74.4±9.8-years-old, Caucasian (66.8%), male (70.3%), with hypertension (71.1%), current smoking (24.5%), coronary atherosclerotic disease (26.2%), and AAA (71.0%). The most common malignancy was lung cancer (48.4%) with most chemotherapy regimens including a platinum-based alkylating agent and concurrent antimetabolite (56.0%). The overall median follow-up time was 28.2 (range 3.1-174.4) months. Aortic aneurysms in patients without malignancy grew to larger sizes (4.43±0.96 vs. 4.14±1.00, P=0.008) with similar median growth rates (0.12 vs. 0.12cm/year, P=0.090), had more atypical morphologic features (14.1% vs. 0.6%, P<0.001), more frequently underwent repair (22.1% vs. 8.7%, P=0.001), and more frequently required emergency repair for rupture (5.4% vs. 0.0%, P=0.087). Cox regression identified initial aortic size ≥4.0cm (hazard ratio [HR] 3.028), AAA (HR 2.146), chronic aortic findings (3.589), and the use of topoisomerase inhibitors (HR 2.694). Linear regression demonstrated increased growth rates predicted by antimetabolite chemotherapy (β 0.170), initial aortic size (β 0.086), and abdominal aortic location (β 0.139, all P<0.002). Small aortic aneurysms with concomitant malignancies are discovered at smaller initial sizes, grow at similar rates, require fewer interventions, and have fewer ruptures and acute dissections than patients without malignancy. Antimetabolite therapies modestly accelerate aneurysmal growth, and patients receiving topoisomerase inhibitors may require earlier repair. Patients with concomitant disease can be confidently treated according to standard institutional aneurysm surveillance protocols. Overall, we recommend treatment of the malignancy before small aortic aneurysm repair as these aneurysms behave similarly to those in patients without malignancy.