PS01.121: DISTRIBUTION OF MEDIASTINAL LYMPH NODE INVOLVEMENT IN ADENOCARCINOMA OF THE ESOPHAGOGASTRIC JUNCTION

Background The distribution of mediastinal lymph node involvement is not clear in patients with adenocarcinoma of the esophagogastric junction (AEG). Based on our experiences with radical lymphadenectomy of upper mediastinum for esophageal squamous cell carcinoma, we applied this technique to patients with AEG. We retrospectively investigated it and compared it with that in patients who had lower esophageal squamous cell carcinoma (ESCC) with clinical invasion of the esophagogastric junction. Methods Sixty-four patients underwent esophagectomy via a right thoracotomy or a minimally invasive esophagectomy for Siewert type I tumor or type II with ≥ 3 cm esophageal invasion. The incidences of mediastinal lymph node involvements and the characteristics of patients with mediastinal nodal involvement were analyzed retrospectively. In addition, these outcomes were compared with 72 patients who had lower ESCC with clinical invasion of the esophagogastric junction. Results In 64 patients with AEG, mediastinal lymph node involvement was seen in 23 patients (36%). The incidences of upper, middle, lower mediastinal nodal involvement were 19%, 16%, and 22%, respectively. No significant differences were found for cStage, Siewert type, endoscopic tumor length, pT or pN status, residual tumor, or survival between patients with upper nodal involvement and those with middle or lower nodal involvement. The incidence of each mediastinal lymph node involvement was similar between AEG and lower ESCC patients. Conclusion Although our outcomes were based on limited data, the incidence of upper, middle, and lower mediastinal lymph node involvement might not be low, and its clinical characteristics were similar to those for middle or lower mediastinal nodal involvement in esophageal adenocarcinoma. Disclosure All authors have declared no conflicts of interest.

Phase 2 trial of chemotherapy followed by consolidative radiation therapy for initial treatment of oligometastatic NSCLC.

9047 Background: Unselected patients with stage 4 lung cancer who receive front line platinum based chemotherapy and maintenance chemotherapy have demonstrated a PFS less than 6 months with very few patients alive at 5 years. Patients with a small number of metastatic lesions may have a different biology, and aggressive local treatment of oligometastases is an active area of investigation. Methods: Patients were required to have stable disease or response after 3-6 cycles of platinum based chemotherapy and PS 0-2. Oligometastatic disease was defined as a maximum number of 5 metastatic lesions for all disease sites including no more than 3 active extracranial metastatic lesions. Limited mediastinal lymph node involvement was allowed. Results: 29 patients were enrolled between 10/2010 and 10/2015. 3 patients were excluded from analysis due to concerns regarding eligibility/treatment response. Despite closing early due to slow accrual, the study met its primary endpoint for success which was PFS greater than 6 months. The median PFS (95% CI) was 11.0 months (7.4-15.9 months) and the median OS was 22.2 months (13.3-45.7 months). The 1-year, 3-year, and 5-year OS were 73%, 35%, and 29%. Conclusions: Patients with oligometastatic NSCLC who received platinum based chemotherapy followed by oligometastatic consolidative radiation without maintenance chemotherapy demonstrated prolonged disease control and overall survival. Clinical trial information: nct01185639.

In hindsight if treatment had begun early: A study to determine the OS and PFS in patients with stage III lung carcinoma based on the time elapsed from the diagnosis to start of treatment.

230 Background: Stage III non-small cell lung cancer (NSCLC) is defined as loco-regionally advanced disease due to primary tumor extension into the extra-pulmonary structures (T3 or T4) or mediastinal lymph node involvement (N2 or N3) without evidence of distant metastasis. Patients are concerned about beginning treatment early after diagnosis. The role of the study is to determine the outcome if treatment is started within 8 weeks or after 8 weeks. In a retrospective study, the Cleveland Clinic’s database was used to identify patients treated through 2003 – 2014. Methods: Stage III NSCLC was ascertained as per the pathological or clinical stage. Kaplan-Meier estimate was used to determine the survival of patients. Results: Of the 561 patients patients with stage III NSCLC, 408 had treatment within 8 weeks and 153 after 8 weeks. See table. Treatment within 8 weeks of diagnosis: In total, 105 patients were recorded as having died, the median survival was 55.1 months (95% CI: 48.2, 62.5). The 2-year survival rate was 98% ± 0.9%, and the 5-year survival rate was 44.5% ± 4.7%. The median PFS was 15.3 months (95%Ci 12.0, 23.1). The 2-year PFS was 43% ± 0.28%, and the 5-year PFS was 14.5% ± 2.1%. Treatment after 8 weeks of diagnosis: In total, 34 patients were recorded as having died, the median survival was 60.6 months (95% CI: 50.3, 73.8). The 2-year survival rate was 97.5% ± 1.4%, and the 5-year survival rate was 53.2% ± 8.3%. The median PFS was 12.1 months (95%Ci 9.5, 15.3). The 2-year PFS was 32.8% ± 4.4%, and the 5-year PFS was 12.8% ± 3.2%. Among the following sub-groups: < 65 years, 65-75 years and > 75 years, there was no observable difference whether treatment was begun within eight weeks or after eight weeks. Conclusions: In the combined group and within subgroups, OS and PFS were not significantly different between patients who received treatment within 8 weeks and those who received treatment after 8 weeks. [Table: see text]

Effect of LINAC-based postoperative radiotherapy on local control and survival in patients with non-small cell lung cancer

AimTo perform a retrospective analysis of survival, local–regional control and the effect of prognostic factors in 61 non-small cell lung cancer patients who were treated with postoperative radiotherapy (PORT) by a linear accelerator (LINAC).Material and methodsA total of 50–66 Gy PORT with a fractional dose of 1·8–2 Gy was administered to 24 patients (24·5%) for surgical margin positivity, 33 patients (54%) for mediastinal lymph node involvement and 13 patients (21·5%) for both mediastinal lymph node involvement and positive surgical margins.ResultsMedian follow-up was 17 months, and the median survival and median distant metastasis-free survival were 25 and 19 months, respectively. Local-regional progression was observed in 10 patients (16·4%). Treatment modality (2D/3D) (p=0·021), tumour size >4 cm (p=0·004), surgical margin positivity (p=0·001), and left lung localisation of the tumour (p≤0·05) were the prognostic factors in terms of survival.ConclusionsA survey of the literature shows that, without PORT, local recurrence or progression rates increase while overall survival rates decrease. In this study, only patients with PORT are studied and the results show that the local progression and overall survival rates are comparable with literature of LINAC-based PORT. In the case of overall survival, 3D treatment shows better results than 2D treatment modality.