Treatment strategies for thymic carcinoma in a real-life setting: Insights from the rythmic network.

Abstract

9072 Background: Thymic carcinomas are an aggressive and difficult to treat subset of thymic epithelial tumors (TETs) that represent a heterogeneous group of rare intrathoracic malignancies. Most of the current knowledge and guidelines tumors rely on surgically-oriented databases focusing on early-stage disease, and small prospective, single-arm trials conducted in metastatic thymic carcinomas, mostly in a refractory, late-line setting. “Réseau tumeurs THYMiques et Cancer” (RYTHMIC) is the nationwide network for TETs in France. The management of any patient has to be systematically discussed on a real-time basis at a national multidisciplinary tumor board; a database is hosted by the French Thoracic Cancer Intergroup (IFCT). Methods: We took advantage of the RYTHMIC prospective database to describe baseline characteristics, analyze treatment strategies, and provide landmark outcomes in a cohort of consecutive patients with thymic carcinoma. The inclusion period was January 2012 to April 2017. Results: A total of 213 patients were analyzed. Overall, 60 (28%) patients were considered as surgical candidates upfront, 91 (43%) received primary chemotherapy, and 62 (29%) received exclusive chemotherapy. Median OS was 49.2 months (IC95%: 34.8-63.6); OS was significantly longer in patients with a lower stage at diagnosis (p < 0.001), who were operated on upfront, as opposed to patients who received primary or exclusive chemotherapy (p < 0.001). Surgery, conducted upfront or after primary chemotherapy, was significantly associated with more prolonged OS (p < 0.001); complete resection and postoperative radiotherapy were also predictors of better outcome (p = 0.018 and p = 0.081, respectively). Exclusive chemotherapy was delivered to 62 patients with advanced disease, who all received platinum-based regimen as first-line treatment; PAC regimen was delivered to 66% of patients. Best objective response to first-line chemotherapy was partial response in 33 (53%) patients. Median PFS was 8.0 months (IC95%: 5.0-11.1). Median OS was 32.9 months (IC95%: 20.6-45.1). Response to first-line chemotherapy and squamous histology were the only significant predictors of OS (p = 0.002 and p = 0.040, respectively). Conclusions: Our cohort is the first to analyze in depth outcomes and treatment strategies in a prospective cohort of consecutive patients with thymic carcinoma. While we confirm the major prognostic impact of surgery, our data highlight the need for optimized multidisciplinary management and innovative therapies as the survival of patients remains limited.