Radiotherapy Significantly Improves Long-Term Survival And Local Control Of Head And Neck Rhabdomyosarcoma (HNRMS) In Adults: Retrospective Analysis Of 64 Patients

Abstract

Rhabdomyosarcomas in adults were rarely reported in the literature. The aim of this study was to analyze the primary site, stage, treatment and prognosis of HNRMS in Adults. The clinical data of adult patients with pathologic diagnosis of HNRMS admitted from October 1999 to July 2018 in Chinese Academy of Medical Sciences Cancer Hospital were retrospectively analyzed. The clinical staging and risk grouping were performed according to International RMS Study Group (IRSG) criterion. A total of 64 patients were included (30 males, 34 females). The median age was 28 years (16-69ys). The pathological type consisted of 28 (43.8%) embryonic RMS, 25 (39.1%) alveolar RMS and 5 (7.9%) pleomorphic RMS. 21 patients (32.8%) got tumors invasion of parameningeal, 38 patients (59.4%) had orbital invasion, included 19 patients (29.7%) had both orbital and parameningeal invasion. IRSG I-IV stage accounted for 57.8%, 10.9%, 18.8%, 12.5% of all the patients. 35.6% patients were classified as low risk, 50.8% patients as medium risk and 13.6% patients as high risk. 28 patients (43.8%) received radical resection, 13 patients achieved R0 resection. 54 patients (84.4%) received radical /adjuvant radiotherapy. Median dose was 69.96Gy (37.5-71.04Gy) of GTV / GTVtb. 46 patients (85.2%) received cervical lymphatic drainage area radiation. A total of 44 patients (68.8%) median completed 4 cycles (1-12 cycles) of chemotherapy. The main chemotherapy regimen was IFO + EPI (52.3%) and CTX + VCR + EPI (25%). Median follow-up for surviving patients was 48 months. 47 patients (73.4%) failed after the treatment, 14 (21.9%) had local recurrence, 34 (53.1%) had distant metastasis. 43 patients (67.2%) were died. The overall 1-, 3- and 5-year over survival (OS) rates were 81.7%, 35.7% and 23.7%, respectively. The median survival time was 20 months. The addition of radiotherapy in treatment significantly improved the OS, progression free survival (PFS) and local-regional recurrence free survival (LRRFS) (3ys OS 36.5% vs 21.8% P = 0.03, 3ys-PFS 27.2% vs 0% P < 0.01, 3ys-LRRFS 77.1% vs 0% P < 0.01). There was no significant difference in LRRFS between patients who received radical radiotherapy and patients received radical surgery (3ys-LRRFS 76.2% vs 70.9% P = 0.79). Multivariate analysis indicated that addition of radiotherapy was the only independent prognostic factor associated with improved OS (RR:0.40, 95%CI 0.20-0.90, P = 0.03). The Adult HNRMS is a kind of tumor with high malignancy and poor prognosis. Radiotherapy added to treatment significantly improved long-term OS and PFS. However, multimodality treatment (surgery, radiotherapy, and chemotherapy) planning and risk stratification is required for all patients to improve the prognosis of Adult HNRMS.