Predictive scoring systems for distant metastases in oral cavity squamous cell carcinoma.

Abstract

e18536 Background: At least 10% of patients with oral cavity squamous cell carcinoma (OCSCC) would progress to distant metastases (DM). Median overall survival (OS) after distant metastases is only one year and rare biomarkers are available to predict distant metastatic events. Methods: A total of 595 OCSCC patients who underwent curative surgical resection at Chung Shan Medical University Hospital were enrolled from Jan 2010 to Dec 2016. The clinical–pathological variables were compared using the χ2 test. Cox proportional-hazards analyses were performed for distant metastatic free survival (DMFS), defined from the date of initial diagnosis to the date of distant metastasis. Two scoring systems for predicting distant metastases were established for patients with pathologic regional lymph node –positive (pN+) or –negative (pN–), separately. Results: Nearly 10% (8.9%, 53/595) of patients with OCSCC would progress to DM during follow-up [20.6% (28/136) and 5.4% (25/459) for patients with pN+ and pN–, respectively]. Most of the distant metastatic lesions developed within 3 years after initial diagnosis (overall, 84.9%, 45/53; patients with pN+, 92.9%, 26/28; patients with pN–, 76.0%, 19/25). For patients with pN+, rapidly locoregional recurrence (≦6 months), lymphovascular invasion, and lymphocyte-monocyte ratio(<2.5) were the independent factors for DMFS. In addition, rapidly locoregional recurrence, elderly (age > 65), and close surgical margin(≦5mm) were independent for those with pN–. If each of the independent factors was scored one point to predict DM occurring within 3 years after the initial diagnosis, two scoring systems were established for the corresponding patients with pN+ or pN–, separately. The area under the curves of these two scoring systems for the corresponding patients with pN+ and pN– were 0.737 and 0.825, respectively (Table). Conclusions: The established scoring systems effectively predict distant metastases for OCSCC patients. [Table: see text]