6001 Background: Chemoradiation (CRT) for HPV (+) SCCOP is associated with a more favorable prognosis than HPV-negative (-) SCCOP. However, the interaction of HPV and T in terms of etiology and disease progression remains unclear. HPV (+) SCCOP pts were prospectively studied to determine if T use was a key variable in discriminating which pts would develop DM, locoregional recurrences (LR), or second primaries (SP). Methods: From 1999–2007, 124 pts with stage III/IV SCCOP were enrolled in one of two CRT trials. Tumor specimens were analyzed for HPV presence and type. Use of T, determined via self-reporting and chart review, was recorded as both continuous (number of pack-yrs) and categorical (never, former, and current) variables. Former T users were subdivided into an early cessation group (quit ≥ 20 yrs prior to diagnosis) and a late cessation group (quit < 20 yrs prior to diagnosis). T use and HPV status were analyzed with respect to survival & the development of DM, LR, or SP. Results: Of the 124 pts, 100 (81%) were HPV (+), 22 of which developed disease progression (22%). Twenty-four were HPV (-), 12 of which had disease progression (50%). Seventeen of 124 pts (14%) developed DM [12 HPV (+), 5 HPV (-)]. Nine of 124 (7%) developed LR [5 HPV (+), 4 HPV (-)], and 8 of 124 (7%) developed SP [5 HPV (+), 3 HPV (-)]. Thirty-two HPV (+) pts were never-T users, 88% (28/32) of which remain alive with no evidence of disease; 3 died from other causes and 1 died of lung metastases from SCCOP. Sixty-eight were HPV (+) and had T exposure. Of 46 former T users, 37/46 (80%) are living. Twenty were HPV (+) and in the early cessation group, 35% (7/20) of which had disease progression [3 LR, 3 DM, 1 SP]. Twenty-six HPV (+) pts were former T users in the late cessation group, 11% (3/26) of which had disease progression [2 DM, 1 SP]. Of 22 HPV (+) current T users, 68% (15/22) are alive and 36% (8/22) have developed disease progression. Seventeen of the 24 HPV (-) pts were current T users, 47% (8/17) of which developed disease progression. Conclusions: Never-T users with HPV-positive SCCOP have improved survival & reduced risk of disease progression compared to HPV (+) & HPV (-) former & current T users. No significant financial relationships to disclose.
