EP1.15-10 Survival Impact of Non-Surgical Treatment in Thymic Epithelial Tumours: A Retrospective Study

The management of thymic epithelial tumours, although poorly defined due to their rarity, remains multidisciplinary in order to offer patients multimodal treatment with surgery as the therapeutic pillar. Our main objective is to highlight the impact of non-surgical treatments on the overall survival and the progression free survival of patients treated for these tumours at the Mohamed VI center. We carried out a monocentric, descriptive and retrospective study using databases from the oncology, the thoracic surgery and anatomopathology departments of the Ibn Rochd University Hospital in Casablanca. We identified all patients with thymoma or thymic carcinoma whose histological diagnosis was made on a biopsy or a surgical excision piece between July 2006 and February 2016 After exclusions, 42 patients were identified and we used a farm sheet to specify for each patient, epidemiological data, data related to histological type, Masaoka-Koga staging and progress under treatment (complete or partial response, stabilization or progression) For our analysis, we used Microsoft Office, Excel 2007 and Kaplan Meier Software to assess overall ans progression free survival. 42 cases of thymic epithelial tumours were reported between 2006 and 2016 with apredominance of type B1 in patients aged between 25 and 77 years. The radiological assessment carried out before treament showed that 9.5% of the diseases were metastatic from the outset, while the others had an intra – thoracic locoregional extension Half of the patients were resectable from the outset, wich made it possible to perform primary surgery leading to carcinological resection with generally simple post-operative outcomes. In our series, CAP D1 = D21 chemotherapy was the preferred regimen to be indicated as a pre operative treatment to reduce the size of the tumor and increase its resectivity rate in 11 patients (26,2% of cases). This chemotherapy was indicated as adjuvant treatment in 06 cases of incomplete resection (14,3% of cases) Two patients (4,8% of cases) received first chemotherapy followed by exclusive radiation therapy at 66 Gy while more than 25% received a post-operative radiation therapy at variable doses ranging from 50-54Gy for R0 tumours or microscopic disease to 60-70Gy for macroscopic disease. The overall and progression free survivals at 22 months were 94,6% and 68,4% respectively. The prognostic factors are, in univariate analysis, the performans status, the histological type, the Masaoka-Koga stage and the quality of surgical resection. The multivariate analysis could not be performed due to a lack of statistical power, due to the small number of patients and the retrospective nature of the study. The thymic epithelial tumours treatment is a real challenge given the absence of randomized prospective studies on this subject Surgery remains the mainstay of management but neo-adjuvant and or adjuvant treatments can be considered in case of poor prognostic factors in order to reduce the risk of recurrence or death from the disease.