Outcomes of Patients with ≥ 8mm Indeterminate Pulmonary Nodules at the Time of Liver Resection for Metastatic Colorectal Cancer.

BACKGROUND: The significance of indeterminate pulmonary nodules (IPNs) at the time of definitive surgical resection of colorectal liver metastases (CRLM) is not well understood. We examined how the presence of IPNs at the time of resection of liver metastases impacts clinical outcomes and identified predictive factors for the development of pulmonary metastases. METHODS: Adult patients with CRLM who underwent curative intent liver resection between 1/2005 and 12/2022 were retrospectively identified and included if an IPN was present pre-operatively. Overall survival and time to pulmonary metastasis were analyzed using Kaplan-Meier; univariate/multivariate Cox regression identified predictive factors. RESULTS: Of the 517 patients who underwent surgical resection of CRLM, 36 (7%) had IPNs. The median overall survival for patients with IPNs was 52.5 month compared to 62.7 months for those without IPNs (p = 0.0072). Of the 31 patients with IPNs with long-term follow-up, 13 (42%) developed pulmonary metastases from an IPN. No significant differences in baseline characteristics were observed between patients whose IPNs progressed to pulmonary metastasis. There were non-significant trends toward higher rates of left-sided primary tumors, metachronous presentation, bilobar and larger-volume hepatic disease (≥5cm), and spiculated pulmonary nodules in the cohort whose IPNs later progressed to pulmonary metastases. CONCLUSIONS: Patients with IPNs detected prior to CRLM resection had a shortened overall survival. However, presence of IPNs alone should not exclude patients from curative surgery, as outcomes remain excellent.