Metastases harbored in the maxillofacial region: Patient and cancer related characteristics and outcomes.

Abstract

e18029 Background: Maxillofacial metastases from distal primary sites are rare, accounting for less than 1% of all newly diagnosed cancer in the head and neck region. Clinical manifestation is non-specific and lesions are often misdiagnosed as benign or inflammatory lesions, and mistreated. We sought to describe maxillofacial metastases and evaluate associations with treatment and patient related outcomes. Methods: Data from all patients diagnosed with cancer in the maxillofacial region between 2008-2020 were extracted retrospectively from the hospital registry, and those with radiological and histological evidence of metastatic lesions were included in the analysis. Patient demographics, clinical presentation, features of primary cancer and treatment were collected. Paired t-tests and univariate regression models were used to evaluate an association between variables and overall survival (OS). Results: Of 532 patients diagnosed with cancer in the maxillofacial region, 15 (2.8%) were found to have metastases from distal primary cancers and included in the study. The group comprised 8 males (53.3%) and 7 females (46.6%), mean age 69 years (range 43 -88) and most common primary malignancies were lung (27%), gastrointestinal (27%) and prostate (20%), with 60% adenocarcinoma histology and the rest SCC and undifferentiated carcinoma. Presenting symptoms included trismus, pain, and swelling in 40% of cases. Clinically, most intraoral manifestations were classic oral ulcerations while the most frequent extra oral features were diffuse pre-auricular and mandibular swelling. Mean time to diagnosis was 22 days (range 7-60), however, intraoral lesions were diagnosed numerically earlier than extra oral (18 vs 23 days, p = 0.5). The mandible was the primarily involved hard tissue location (40%), and the parotid, for soft tissue lesions (33%). Mean SUV for PET-CT scans was 4.4 (range 2.0-10.93) and CT demonstrated bone expansion and lysis (50% each) and periosteal reaction (33%). In total, 60% of patients in the study had a change to their treatment after diagnosing the metastasis, while 40% with direct radiation (30-70 Gy) to the metastatic site. Median OS was 5 months while 60% of patients in the study group survived less than 6 months. Despite being twice as likely to receive treatment (75% vs 37.5%), patients with intra oral metastases had significantly shorter survival than those with extra oral metastases (13.3 vs 2.9 months, 95% CI 3.025-17.689, p < 0.01). No other associations were observed between patient demographics, cancer type and treatment, with survival. Conclusions: The maxillofacial region appears to be a late site for cancer metastasis, with non-specific presentation. As patient survival outcomes improve across cancer types and the array of possible alternative diagnoses increases, clinicians should be aware of this entity to ensure rapid referral for diagnosis and palliative treatment.