Outcomes of Incidental Pulmonary Nodules in Head-and-Neck Squamous Cell Cancer Patients Treated with Curative Intent

Introduction: Incidental pulmonary nodule(s) (IPNs) are a common finding during staging imaging for the head-and-neck squamous cell cancers (HNSCC) treated with curative intent. Currently, the incidence of metastasis or synchronous malignancies and outcomes for IPN in this population is unknown. Methods: All cases (n = 2489) reviewed at a tertiary Australian Institution's head and neck (H and N) multidisciplinary meeting, from January 2010 to December 2014, were included. Of these patients, 310 (12.5%) had an HNSCC with an IPN that had been detected during staging imaging. These patients were also to undergo treatment by curative intent. Clinicopathological characteristics, the incidence of malignancy, progression-free survival, and overall survival (OS) were collected retrospectively over 5 years. Results: The median age of patients with an IPN was 66 (range 25-95) years. Tissue diagnosis of IPN was attempted in 46 (14.8%) patients due to radiological suspicion of malignancy. Malignancy was confirmed in 33 (11.0%) patients. From these, 33 patents, 11 (30.3%) had histological diagnoses of nonsquamous cell lung cancers and hence are not due to metastatic spread from a primary HNSCC. Age, gender, previous malignancies, smoking status, p16 status, stage, or primary site did not predict for malignancy. The incidence of pulmonary metastasis in patients who did not undergo tissue biopsy due to low clinical and radiological suspicion of malignancy (n = 244) occurred in 10 patients (4.1%). At the time of analysis, 91 (29.4%) patients had died. and tumor recurrence had occurred in 82 (26.5%) patients. The mean OS was 48 months (95% confidence interval: 44-51). OS was significantly associated with greater age (hazards ratio [HR] 1.04, P < 0.001); immunosuppression (HR 2.15, P = 0.013); and biopsy being attempted (HR 1.78. P= 0.013). There was no biopsy related mortality. Discussion: Detection of an IPN in patients undergoing workup for H and N cancer is common. The risk of malignancy in these IPNs however, is low. We did not identify any clinicopathological parameters to predict malignancy in this setting. Advanced age, current smoking status, and history of immunosuppression predict for poor outcomes. Further work is being undertaken to analyze radiological features that may predict malignancy in an IPN found during the radiological staging of HNSCC.