Clinical Characteristics and Long-Term Outcomes following Surgery Combined with Adjuvant Radiotherapy for Patients with Frontal Sinus Malignancies.

Primary frontal sinus malignancies (FSMs) are the rarest sinonasal cancers. This study aimed to determine clinicopathologic characteristics of primary FSMs and provide long-term survival outcomes.  This study is a retrospective review.  The study was conducted at a tertiary medical center.  Patients who participated in this study were diagnosed with primary FSMs.  Median survival time is the primary outcome measure of this study.  In this series, the median age was 48 years (30-53 years) and all patients were male. There were five cases with squamous cell carcinoma and one with osteosarcoma. All cases presented with locally advanced disease without regional lymphatic metastasis, including five cases of stage III and one case of stage II. The two most common pathways of tumor invasion were as follows: local tumor broke posteriorly through bone wall and invaded dura mater, followed by frontal lobe; local tumor infiltrated downward through the floor of frontal sinus into ethmoid sinus, thereafter invaded laterally orbit and orbital contents. All patients received surgery followed by postoperative radiotherapy at the total doses of 50 to 75.95 Gy. Among them, only one patient underwent R0 resection, the rest of patients underwent R1/R2 resection. With a median survival time of 56 months (32-76 months), two patients receiving R1/R2 resection developed treatment failure and died within 5 years, including one case with local recurrence and one with local recurrence, thereafter distant metastasis.  The majority of FSMs presented with peripherally invasive progression lesions which led to a high ratio of R1/R2 resection. Surgery combined with postoperative radiotherapy might result in satisfactory efficacy.