Clinical and pathological characteristics, treatment outcome and prognostic factors in adult rhabdomyosarcoma: a monocentric retrospective study

Rhabdomyosarcoma (RMS) is rare in adults. Our study is the first in Tunisia to report outcomes of adult RMS. We retrospectively analyzed clinical data of adult RMS patients. We collected data regarding clinical characteristics, treatment outcome and prognostic factors. Survival was assessed using the Kaplan Meier method. Forty-seven patients were included. Median age was 39. Twenty-five patients were young adults (53%). Sex ratio (M/F) was 1.9. RMS was localized in 33 patients (70%) and metastatic in 14 patients (30%). Extremities were the most frequent tumor site (40%) followed by trunk (23%). Median tumor size was 9 cm. Pleomorphic RMS was the major subtype (36%). Twenty seven of 33 patients with localized RMS underwent surgery (82%). Relapse free survival (RFS) was 38%. Young adults had a significantly worse RFS than adults aged ≥40 (p = 0.045). Surgery was associated with a significantly better RFS (p = 0.023). Five year overall survival (OS) was 35% and 27% in localized and metastatic RMS respectively. RMS localized in the extremities had significantly poorer OS (p = 0.041), same as non-operated patients (p = 0.025). OS for metastatic RMS was significantly worse after surgery of the primary tumor (p = 0.002). In multivariate analysis, surgery (HR = 0.108; 95%CI (0.023-0.519); p = 0.005) and non-extremity localization (HR = 0.238; 95%CI (0.075-0.751); p = 0.014) were independent prognostic factors for OS in localized RMS. Adults with RMS have poor 5 year OS. Surgery and non-extremity localization were independent prognostic factors for OS in localized RMS.