Objective: Albeit rare, rhabdomyosarcoma (RMS) may occur in middle to old-aged adults. The purpose of this study was to investigate the clinicopathological characteristics and prognosis of RMS in patients ≥ 40 years of age.
Methods: The clinical, pathological and immunohistochemical profiles of the 76 cases were reviewed, and the outcomes were analyzed.
Results: There were 46 males and 30 females with a median age of 55 years. Sixty cases occurred in somatic soft tissues, including extremities (n = 25), head and neck (n = 19) and trunk (n = 16). Sixteen developed in the internal organs with predilection for the urogenital tract. Histologically, 38 cases (50.0%) were of embryonal RMS (ERMS) subtype, 29 cases (38.2%) of pleomorphic RMS (PRMS), 7 cases (9.2%) of poorly-differentiated RMS (PdRMS), and 2 cases (2.6%) of alveolar RMS (ARMS). Immunohistiochemically, the tumor cells showed diffuse staining of desmin (68/68, 100%), with a variable expression of myogenin (30/43, 69.8%), MyoD1 (33/51, 64.7%) and MSA (29/40, 72.5%). The therapy data available in 54 cases showed that three inoperable cases were treated with chemotherapy and radiotherapy, 51 cases underwent local excision, including 10 cases with chemotherapy, 9 cases with radiotherapy, 8 cases with chemotherapy and radiotherapy after surgery, and the remaining 24 cases were not administrered with postoperative adjuvant therapy. The follow-up data available in 54 cases showed that 22 patients were alive with unresectable or recurrent/disease and 32 patients were alive with no evidence of disease. The median disease-free and overall survivals were 6.0 months and 7.0 months, respectively. Twenty-seven patients exhibited progression of disease with recurrence in 8 cases and metastasis in 19 cases. The median interval to progression was 6.0 months.
Conclusions: The most common subtypes of RMS in middle to old aged patients are ERMS and PRMS. In general, Rhabdomyosarcomas of middle to old aged patients shows a highly aggressive behavior. Patients may benefit from multi-disciplinary therapy.