Patterns of Treatment Failure in Patients with Infratemporal Fossa Malignancies

Purpose: Malignant tumors of the infratemporal fossa (ITF) have historically been associated with poor prognosis. This report updates long-term outcomes of this disease site at the University of Texas M.D. Anderson Cancer Center. We aimed to identify independent predictors of outcome and to characterize the patterns of failure.

Methods: Retrospective analysis of 330 patients who presented with malignant tumors involving zone II (i.e., infratemporal and pterygomaxillary fossa and middle cranial fossa extending from the petrous temporal bone to the posterior orbital wall) between January 1999 and December 2018. Patients with histologically proven malignancy of the ITF treated surgically with curative intent were included. Clinical and pathologic nodal status was evaluated and characterized for all patients. Multivariate analysis assessed associations of regional spread with survival outcomes.

Results: One hundred and thirteen patients were included in this study. Median age was 50 years (range: 8–84 years). Malignant tumors histology was distributed as follows: sarcoma n = 59 (52%), squamous cell carcinoma n = 25 (22%), hemangiopericytoma n = 8 (7%), chordoma n = 5 (4%), adenocarcinoma n = 5 (5%), basal cell carcinoma n = 3 (2%), mucoepidermoid carcinoma 2 (2%), carcinoma ex pleomorphic adenoma n = 1 (1%), neuroendocrine carcinoma n = 1 (1%), and melanoma n = 1 (1%). There were 3 (3%) cases of primary central nervous system involving the ITF. Neoadjuvant chemotherapy was administered to 32 (28%) patients, of those 7 (7%) patients received neoadjuvant concurrent chemoradiotherapy. Postoperative adjuvant radiation was administered in 54 (48%) patients, of those 13 (13%) patients received concurrent chemoradiotherapy. Median dose for patients receiving postoperative RT was 60 Gy. Median follow-up for the entire cohort was 43 months (range: 2.6–203.7 months). Five-year overall and disease-specific survival rates were 47 and 56%, respectively. Recurrence occurred in 39 patients (35%); 31 patients had local recurrence, 8 (8%) had distant recurrence, and 6 (5%) had regional recurrence. Five-year disease-free survival rate was 44%. Multivariate analysis revealed that metastatic tumor (HR: 15.3; 95% CI: 2.03–87.5), chordoma (HR: 5.56; 95% CI: 1.69–22.2), positive resection margins (HR: 2.86; 95% CI: 1.3–6.19), and adjuvant radiotherapy (HR: 0.49; 95% CI: 0.2–0.8) are significant predictors of disease-specific survival.

Conclusion: Sarcomas of the skull base are the most common malignancies involving the ITF. The most common pattern of failure is local recurrence. Poor survival rates were associated with metastasis to the ITF, chordoma histopathology and pathological positive margin status. Adjuvant radiotherapy was associated with improved survival. These prognostic estimates should be considered when counseling patients with ITF malignancies.

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