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

Thymic carcinomas are aggressive and difficult to treat a subset of thymic epithelial tumours that represent a heterogeneous group of rare intrathoracic malignancies. The treatment strategy of thymic carcinomas is based on whether surgical resection may be achieved, which represents the most significant favourable prognostic factor on survival. For this study, we took advantage of the unique prospective Réseau tumeurs THYMiques et Cancer (RYTHMIC) database to describe baseline characteristics, analyse treatment strategies in light of existing guidelines and provide landmark patient outcomes data with regards to response and survival of patients in a real-life clinical practice setting.

Inclusion criteria for this analysis were the following: (1) histologically-confirmed thymic carcinomas - excluding neuroendocrine tumours-after pathological review by the RYTHMIC pathology panel, (2) discussion of the case at the RYTHMIC multidisciplinary tumour board, (3) at least one active treatment modality.

A total of 213 patients were analysed. Overall, 60 (28%) patients were considered as surgical candidates upfront, 91 (43%) patients received primary chemotherapy, and 62 (29%) patients received exclusive chemotherapy. Median overall survival (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 = 0.051, respectively).

Our cohort is the first to analyse 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 optimised multidisciplinary management and innovative therapies as the survival of patients remains limited.