Survival in patients with HPV-positive oropharynx squamous cell carcinoma with distant metastases.

Abstract

6095 Background: Prognosis for patients (pts) with locally-advanced, HPV-positive oropharynx squamous cell carcinoma (HPV+OPSCC) is significantly better than for pts with HPV-negative head and neck squamous cell carcinoma (HNSCC). Historic survival of pts with metastatic HNSCC is 6-9 months with palliative therapy. However, the prognosis and survival of pts with HPV+OPSCC with distant metastases is not known. Methods: Pts with HPV+OPSCC with distant metastatic disease were identified from databases from the departments of surgery, radiation, and medical oncology. Demographic and clinical data was abstracted from the medical record. All pts had confirmed HPV/p16+ disease. Results: Fifteen pts with metastatic HPV+ OPSCC were identified. The median age was 57 years (range 42-78, 15 male). The median pack-year smoking was 0 (range 0-120). Primary site included 10 tonsil and 5 tongue base. At diagnosis, one pt had stage III and 14 had stage IV disease (IVA: 9, IVB: 2, IVC: 3). T- and N-stage included T1 (1), T2 (10), T3 (3), T4 (1) and N1 (1), N2a (1), N2b (9), N2c (3), N3 (1). Extracapsular extension was seen in 8 pts, absent in 2, and unknown in 5. Seven pts had lymph node (LN) involvement at level IV/V. Initial therapy for locally-advanced disease included surgery followed by adjuvant radiation (RT) in 1 pt and chemoRT in 8, and definitive chemoRT in 3 pts. Three pts were metastatic at initial diagnosis. Of 6 pts with an isolated metastatic site, 3 pts are alive > 2 years from diagnosis of metastasis (median 1.97 years, range 0.49-2.29). Palliative therapy included surgery (3), RT (9), platinum chemo +/- cetuximab (8), cetuximab alone (2) or with a taxane (2). The most common sites of metastasis included bone (6), lung (5), and LNs (5). The 1-year survival rate after diagnosis of metastatic disease was 92%. The median time to diagnosis of metastatic disease after definitive therapy was 0.47 years (95% CI 0.19-1.29); 75% of pts who developed metastatic disease did so within 1 year of definitive therapy. Of note, 2 of the 15 pts developed a secondary immune-mediated malignancy (melanoma and non-HIV associated Kaposi’s sarcoma). Conclusions: The survival of pts with metastatic HPV+OPSCC is significantly better than that of historic controls.