Mediastinal Node Recurrence Research Articles

645. CLINICAL SIGNIFICANCE OF LOCAL TREATMENT FOR RECURRENCE WITHIN THE SURGICAL FIELD AFTER RADICAL ESOPHAGECTOMY

Abstract Background In recent years, more aggressive multidisciplinary treatment and minimally invasive approaches with meticulous lymph node dissection have become the standard in esophageal cancer surgery, but recurrence cases within the surgical field after radical resection are unfortunately frequently observed. We will compare the clinicopathological characteristics of the cases of intra-sugical field recurrence with those of extra-surgical and both intra- and extra-surgical field recurrence and discuss their significance in light of the results of local treatment for intra-surgical field recurrence. Subjects The study included 130 cases of intra-surgical field recurrence among 490 esophageal cancer patients who underwent radical subtotal esophagectomy and cervical anastomosis (Mckeown-esophagectomy) with right thoracic approach between January 2013 and April 2019. Results The 130 cases of recurrence were categorized as intra-surgical field recurrence (Group I)/extra-surgical field (Group O)/intra- and extra-surgical field (Group I+O): 19/86/25. Preoperative factors: Tumor localization tended to be more common in Ut in group I (p=0.078), but there were no other differences such as cStage or preoperative treatment. Intraoperative/postoperative factors: I+O group had significantly more blood loss (p=0.045), but there were no other differences in the range of lymph node dissected field, number of dissected lymph nodes, combined resection of the thoracic duct, postoperative complications, hospital stay, or histological therapeutic effect. 19 patients in group I had 17 patients (89.5%) who received initial local treatment (surgery/CRT/RT: 4/7/6). The response rate (R0 resection or CR+PR) was 58.8%. Compared to cervical and upper mediastinal lymph node recurrence, the response rate to initial local treatment tended to be lower in patients with middle and lower mediastinal lymph node and anastomotic recurrence (80%/43%, p=0.145). Discussion Intra-surgical field recurrence after radical resection tended to be more common in the primary site of Ut. Recurrence in the upper mediastinal lymph nodes in the cervical region shows a relatively high response rate to local treatment, and long-term recurrence-free ("cure") is achieved. On the other hand, mid and lower mediastinal lymph node and anastomotic recurrences have a low response rate to local treatment and should be complemented with more systemic treatment, such as sequential ICI to initial treatment.

Omitting Lymph Node Dissection for Small Ground-Glass Opacity–Dominant Tumors

BackgroundThe purpose of this study was to determine the optimal extent of lymph node dissection required in patients with small (≤3 cm) radiologically ground-glass opacity–dominant, peripheral, non-small cell lung cancer tumors. MethodsThe study analyzed the clinicopathologic findings and surgical outcomes of 988 patients with radiologic, ground-glass opacity–dominant non-small cell lung cancer without lymph node involvement who underwent complete resection of the primary tumor between 2010 and 2020. Patients were followed up for 54.5 months (median). Kaplan-Meier curves and the log-rank test were used in statistical analyses of the prognosis. ResultsMedian age, whole tumor size, solid tumor size, and maximum standardized uptake values were 68 years, 1.7 cm, 0.4 cm, and 0.9, respectively. Sixty percent of the cohort was female (n = 590). Wedge resection, segmentectomy, and lobectomy were performed in 206, 372, and 410 patients, respectively. A total of 982 of 988 (99%) tumors were adenocarcinomas. One patient had hilar lymph node involvement; however, no mediastinal lymph node metastasis or hilar or mediastinal lymph node recurrence was detected. The 5-year overall survival rate was 96.5% (95% CI, 94.8%-97.7%). Excellent survival outcomes were achieved regardless of procedure (wedge resection, 94.7% [95% CI, 89.1%-97.5%]; segmentectomy, 96.9% [95% CI, 93.7%-98.5%]; and lobectomy, 97.1% [95% CI, 94.4%-98.5%]). ConclusionsOmitting lymph node dissection may be acceptable with curative intent for small tumors with radiologic ground-glass opacity dominance. Appropriate surgical procedures such as wedge resection, segmentectomy, or lobectomy can provide satisfactory outcomes in patients with indolent tumors if surgical margins are secured.

150. PATTERN OF LYMPH NODE RECURRENCE AFTER NEOADJUVANT CHEMORADIOTHERAPY AND MODIFIED EN BLOC ESOPHAGECTOMY

Abstract Background Esophageal cancer is an aggressive malignancy with high incidence of lymph node metastasis and recurrence rate even after neoadjuvant treatment and radical resection. Previous study has shown that modified en bloc esophagectomy (mEBE) improves survival for esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemoradiotherapy (nCRT). In this study, we aim to investigate the pattern of lymph node recurrence after nCRT+mEBE. Methods The data of patients who received nCRT followed by curative surgical resection for ESCC were retrospectively reviewed. The mEBE includes ‘mesophagus’ dissection and bilateral recurrent laryngeal nerve node dissection, whereas conventional esophagectomy (CE) only requires periesophageal tissues dissection that were close to the esophagus. The pattern of recurrence, especially lymph node recurrence (cervical, upper mediastinum, infra-carina, and abdominal), were compared between CE and mEBE, with stratification according to pathological stage (ypT0N0 or not.) Results A total of 221 (CE, n = 181; mEBE, n = 40) patients were included. Mediastinal lymph node recurrence was noted in 16.0% and 7.5% of patients after CE and mEBE, respectively (p = 0.166). In ypT0N0 patients who received CE, 6.0% had upper mediastinum recurrence, whereas no mediastinal recurrence was noted after mEBE (p = 0.329). In non-ypT0N0 stage patients who received CE, 15.3% and 8.2% had upper mediastinum and infra-carina recurrences, compared to 12.0% and 0% after mEBE (p = 0.283). There cervical/abdominal recurrences were noted in 6.6%/7.2% and 15.0%/5.0% after CE and mEBE, respectively (p = 0.080/0.618). Conclusion Although there was no significant difference in lymph node recurrence pattern between mEBE and CE, we observed that (1) 6% of ypT0N0 patients developed mediastinal lymph node recurrence after CE, implying the possibility of understaging after CE; (2) no patients developed infra-carina lymph node recurrence after mEBE, suggesting the necessity of mesoesophagus dissection, and (3) high incidence of cervical lymph node recurrence even after mEBE, indicating that cervical dissection should be considered in selected patients.

Pattern of relapse following three-field lymphadenectomy of esophageal carcinoma and related factors predictive of recurrence

PurposeFor treatment of esophageal carcinoma, the optimal postoperative radiotherapy target volume after three-field lymph node dissection (3-FLD) had not been determined. We analyzed local recurrence pattern of thoracic esophageal carcinoma and risk factors of lymph node recurrence after 3-FLD without prophylactic radiotherapy. Material and methodsWe reviewed 1282 patients with thoracic esophageal squamous cell carcinoma (ESCC) who were treated with 3-FLD without radiotherapy from 2010 to 2018 and analysed local recurrence patterns and risk factors of lymph node recurrence, in order to provide a reference for determination of the radiotherapy target volume for thoracic ESCC. ResultsThe lymph node recurrence accounted for 91.0% of treatment failures. The mediastinal, cervical and abdominal lymph node recurrence accounted for 84.92%, 36.07% and 22.30%, respectively (χ2=264.776, P=0.000). The superior, middle and inferior mediastinal lymph node recurrence rates were 67.54%, 27.87% and 0.98%, respectively (χ2=313.600, P=0.000). Cervical metastases were significantly associated with N stage and Preoperative cervical lymph node status. Abdominal metastases were significantly associated with the number of preoperative abdominal lymph node metastases (LNM), tumor location and N stage. ConclusionsThe main pattern of local-regional recurrence might be lymph node metastasis after radical 3-FLD without radiotherapy in esophageal carcinoma. The dangerous lymph node recurrence regions included neck, superior and middle mediastinum. The abdominal areas might be irradiated for lower TEC patients with preoperative abdominal LNM.

Primary Tumor Recurrence after Chemoradiotherapy in Limited Stage Small Cell Lung Cancer

<h3>Purpose/Objective(s)</h3> Accounting for 13-15% of lung cancer, small cell lung cancer (SCLC) is typically characterized by more extensive local invasion and more frequent metastases compared with other subtypes. Although SCLC is sensitive to chemoradiotherapy, 25% of the patients with limited stage SCLC would meet local regional relapse. Although thoracic radiation had significantly improved local control, primary tumor recurrence is common in clinic. So far, we had little acquaintance of the local relapse details to help us to make progress in the thoracic radiation. To investigate the patterns of patients with local regional recurrence and the prognosis of primary tumor recurrence, we proposed this study. <h3>Materials/Methods</h3> We searched patients with pathological diagnosis of SCLC, with disease of limited stage, received systemic chemotherapy and thoracic intensity modulate radiotherapy at our center with available follow-up records between August 1^st, 2006 and May 31^st,2014. Patients with intrapulmonary recurrence or regional lymph nodes recurrence by the last follow up time, without diffused lung metastasis were selected. All the patients received involved field thoracic radiotherapy with dose of 2Gy per fraction per day. Data regarding patient demographics and treatments. The first local recurrent sites were recorded. Local regional relapse time was calculated from the first day of the treatment delivery to the diagnosis of primary tumor or regional lymph nodes. Overall survival was calculated from the first day of the diagnosis of local relapse to the death using Kaplan Meir Method. <h3>Results</h3> We identified 482 patients with a diagnosis of limited stage SCLC. Among these, 125 patients fulfilled the eligibility criteria. The median dose of radiotherapy is 60Gy. The median local relapse time was 12.97 months. Primary tumor recurrence, ipsilateral hilar and/or mediastinal lymph node recurrence, contralateral hilar and/or lymph node recurrence, and supraclavicular lymph node recurrence, were observed in 92 patients (73.6%), 49 patients (39.2%), 1 patient (0.8%) and 13 patients (10.4%), respectively. There were 26 patients with multisite local recurrence. Out-field relapse was observed in 6 patients (4.8%). The median follows up time was 34.7 months. After second line therapies, the median survival time for these patients diagnosed as recurrent disease was 10.5 months. Of the 92 patients with primary tumor recurrence, 25 patient received re-radiation and 39 patients also met distant metastasis. Median survival time of patients with primary tumor recurrence is slightly shorter than the others (9.9months vs. 12.0months). <h3>Conclusion</h3> For patients with limited stage SCLC who received chemoradiotherapy, primary tumor recurrence is still the leading course in local regional relapses and accompanied by worse survival. Accordingly, simultaneous integrated boost might be taken into consideration to primary tumor. Involved field radiation is reasonable with low out-field local recurrence.

Stereotactic Body Radiation Therapy (SBRT) for Oligorecurrent/Oligoprogressive Mediastinal and Hilar Lymph Node Metastasis: A Systematic Review.

Simple SummaryThis paper is a review of the literature on oligorecurrent/oligoprogressive mediastinal and hilar lymph node metastasis treated with SBRT. The use of mediastinal SBRT had historically been not feasible in view of the expected toxicity due to the proximity of critical structures such as the airways and esophagus. Despite the heterogeneity and lack of some data in the studies analyzed, this literature review is the first published and can be a valid guide for the radiotherapist in the management of oligometastatic/oligoprogressive patients, with particular regard to the radiotherapy doses, dose constraints for organs at risk, and clinical outcomes.Introduction: Mediastinal or hilar lymph node metastases are a challenging condition in patients affected by solid tumors. Stereotactic body radiation therapy (SBRT) could play a crucial role in the therapeutic management and in the so-called “no-fly zone”, delivering high doses of radiation in relatively few treatment fractions with excellent sparing of healthy surrounding tissues and low toxicity. The aim of this systematic review is to evaluate the feasibility and tolerability of SBRT in the treatment of mediastinal and hilar lesions with particular regard to the radiotherapy doses, dose constraints for organs at risk, and clinical outcomes. Materials and methods: Two blinded investigators performed a critical review of the Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA), starting from a specific question: What is the clinical impact of SBRT for the treatment of oligorecurrent/oligoprogressive mediastinal and hilar metastasis? All retrospective and prospective clinical trials published in English up to February 2022 were analyzed. Results: A total of 552 articles were identified and 12 of them were selected with a total number of 478 patients treated with SBRT for mediastinal or hilar node recurrence. All the studies are retrospective, published between 2015 and 2021 with a median follow-up ranging from 12 to 42.2 months. Studies following SBRT for lung lesions or retreatments after thorax radiotherapy for stage III lung cancer were also included. The studies showed extensive heterogeneity in terms of patient and treatment characteristics. Non-small cell lung cancer was the most frequently reported histology. Different dose schemes were used, with a higher prevalence of 4–8 Gy in 5 or 6 fractions, but dose escalation was also used up to 52 Gy in 4 fractions with dose constraints mainly derived from RTOG 0813 trial. The radiotherapy technique most frequently used was volumetric modulated arc therapy (VMAT) with a median PTV volume ranging from 7 to 25.7 cc. The clinical outcome seems to be very encouraging with 1-year local control (LC), overall survival (OS) and progression-free survival (PFS) rates ranging from 84 to 94%, 53 to 88% and 23 to 53.9%, respectively. Half of the studies did not report toxicity greater than G3 and only five cases of fatal toxicity were reported. CONCLUSIONS: From the present review, it is not possible to draw definitive conclusions because of the heterogeneity of the studies analyzed. However, SBRT appears to be a safe and effective option in the treatment of mediastinal and hilar lymph node recurrence, with a good toxicity profile. Its use in clinical practice is still limited, and there is extensive heterogeneity in patient selection and fractionation schedules. Good performance status, small PTV volume, absence of previous thoracic irradiation, and administration of a high biologically effective dose (BED) seem to be factors that correlate with greater local control and better survival rates. In the presence of symptoms related to the thoracic lymph nodes, SBRT determines a rapid control that lasts over time. We look forward to the prospective studies that are underway for definitive conclusions.

Accuracy of the endoscopic evaluation of esophageal involvement in esophagogastric junction cancer

BackgroundEsophageal involvement length (EIL) is a promising indicator of metastasis or recurrence in mediastinal lymph nodes (MLNs) in adenocarcinoma of the esophagogastric junction (EGJ). This study aimed to elucidate the accuracy of the preoperative endoscopic evaluations of EIL and its clinical significance in this disease. Materials and methodsIn total, 75 patients with Siewert type II (N = 53) or III (N = 22) adenocarcinoma of the EGJ, who underwent surgical resection without preoperative therapy between 1995 and 2016 were enrolled. We retrospectively examined the accuracy of the preoperative endoscopic evaluations of EIL (preoperative EIL), compared to the pathologically evaluated EIL. Finally, we investigated the association between preoperative EIL and metastasis or recurrence in MLNs. ResultsThe accuracy of the preoperative EIL within a 1-cm interval was only 53.3%. Among patients with discordance between the pre- and postoperative evaluations, 68.6 % had the underestimation in the preoperative EIL. pN1–3 (OR = 5.85, 95% CI: 1.03–33.17) and undifferentiated histologic type (OR = 2.52, 95% CI: 0.89–7.14) were potential risk factors for the discordance. Regarding metastasis or recurrence in MLNs, preoperative EIL of 2–3 cm (OR = 10.41, 95% CI: 1.35–80.11) and >3 cm (OR = 8.33, 95% CI: 1.09–63.96) were independent predictors. ConclusionAlthough the accuracy of the endoscopic evaluations of EIL is insufficient with many underestimations, EIL should be assessed in preoperative staging because of significant predictive power for metastasis or recurrence in MLNs.

Mapping of Cervical and Upper Mediastinal Lymph Node Recurrence for Guiding Clinical Target Delineation of Postoperative Radiotherapy in Thoracic Esophageal Squamous Cell Carcinoma.

BackgroundThe lower neck and upper mediastinum are the major regions for postoperative radiotherapy (PORT) in thoracic esophageal squamous cell carcinoma (TESCC). However, there is no uniform standard regarding the delineation of nodal clinical target volume (CTVnd). This study aimed to map the recurrent lymph nodes in the cervical and upper mediastinal regions and explore a reasonable CTVnd for PORT in TESCC.MethodsWe retrospectively reviewed patients in our hospital with first cervical and/or upper mediastinal lymph node recurrence (LNR) after upfront esophagectomy. All of these recurrent lymph nodes were plotted on template computed tomography (CT) images with reference to surrounding structures. The recurrence frequency at different stations was investigated and the anatomic distribution of recurrent lymph nodes was analyzed.ResultsA total of 119 patients with 215 recurrent lymph nodes were identified. There were 47 (39.5%) patients with cervical LNR and 102 (85.7%) patients with upper mediastinal LNR. The high-risk regions were station 101L/R, station 104L/R, station 106recL/R, station 105 and station 106pre for upper TESCC and station 104L/R, station 106recL/R, station 105, station 106pre and station 106tbL for middle and lower TESCCs. LNR in the external group of station 104L/R was not common, and LNR was not found in the narrow spaces where the trachea was in close contact with the innominate artery, aortic arch and mediastinal pleura. LNR below the level of the cephalic margin of the superior vena cava was also not common for upper TESCC.ConclusionsThe CTVnd of PORT in the cervical and upper mediastinal regions should cover station 101L/R, station 104L/R, station 106recL/R, station 105 and station 106pre for upper TESCC and station 104L/R, station 106recL/R, station 105, station 106pre and station 106tbL for middle and lower TESCCs. Based on our results, we proposed a useful atlas for guiding the delineation of CTVnd in TESCC.

Comparison of Local Recurrence Patterns of Postoperative Radiotherapy with Surgery Alone for Esophageal Carcinoma Patients

ABSTRACT Background: We analyzed local regional recurrence patterns of thoracic esophageal carcinoma after three-field lymph node dissection (3-FLD) with and without postoperative radiotherapy, and assessed the postoperative radiation value for local control. Methods: The study reviewed 239 local recurrences of esophageal squamous cell carcinoma after 3-FLD from 2010 to 2018 in our hospital, retrospectively, and compared local regional recurrence patterns between surgery followed by radiotherapy (S+RT) and surgery alone (SA). Results: In 239 thoracic esophageal carcinomas that underwent curative surgery, the lymph node recurrence was the most common type of local recurrence for patients in both groups. The sequence of lymph node recurrence rate in both groups from highest to lowest was mediastinal, cervical, and abdominal. The recurrence rate of superior mediastinal lymph node in patients without radiotherapy was significantly higher than that in patients with radiotherapy (67.72% vs. 47.54%, x2 = 7.615, P = 0.006). The recurrence rate of abdominal lymph node in the upper TEC was significantly lower than that in the middle and lower TEC (x2 = 9.452, P = 0.009). The abdominal lymph node recurrence rate in patients with preoperative abdominal LNM was very significantly higher than that in patients without preoperative abdominal LNM (43.63% vs. 6.66%, P &lt; 0.001). Conclusions: The dangerous lymph node recurrence regions included superior, middle mediastinum, and neck. Postoperative radiotherapy shows great value for patients in reducing superior mediastinal lymph node recurrence rate. The lower segment of thoracic esophageal carcinoma and preoperative abdominal lymph node metastasis, especially para-aortic lymph node metastasis, may be risk factors for abdominal lymph node recurrence.

Long-term outcomes of robotic-assisted versus thoraco-laparoscopic McKeown esophagectomy for esophageal cancer: a propensity score-matched study.

The long-term outcomes of robotic-assisted McKeown esophagectomy (RAME) compared to thoraco-laparoscopic McKeown esophagectomy (TLME) for the patients with esophageal squamous cell carcinoma (ESCC) remain unclear. The aim of this study was to compare the number of dissected lymph nodes and long-term survival between RAME and TLME using a propensity score-matched (PSM) analysis. A total of 721 patients undergoing minimally invasive McKeown esophagectomy at our department from February 2015 to October 2019 were analyzed, including 310 patients in RAME group and 411 in TLME group. The exact numbers of lymph nodes including those among thoracic and abdominal categories as well as those along the recurrent laryngeal nerve (RLN) were all recorded. PSM analysis was applied to generate matched pairs for further comparison. All patients with R0 resection were followed with a strict follow-up period which range from 1 to 56months. The effect of lymphadenectomy was compared between all patients in unmatched and matched groups. Long-term outcomes consisting of overall survival (OS), disease-free survival (DFS) and recurrence rate (including regional recurrence rate, systemic recurrence rate and mediastinal lymph nodes recurrence rate) were compared in R0 resection patients. Finally, 292 patients were identified for each cohort after PSM. RAME was found to yield significantly more left RLN lymph nodes (mean: 2.27 ± 0.90 vs. 2.09 ± 0.79; P = 0.011) and more thoracic lymph nodes (mean: 12.60 ± 4.22 vs. 11.83 ± 3.12, P = 0.012) compared with TLME after PSM analysis. There was no significant difference in the OS and DFS between the RAME and TLME group. Besides, total recurrences were recognized in 33 (11.7%) patients in the RAME group and 36 (12.9%) in the TLME group (P = 0.676). The mediastinal lymph nodes recurrence rate in the RAME group was tended to be lower than that in the TLME group (2.5% vs. 5.4%, P = 0.079). Therefore, RAME might be an alternative approach for the treatment of ESCC with more lymph nodes dissected and similar long-term survival outcomes compared to TLME.

A Case of Esophageal Cancer with Superior Mediastinal Lymph Nodes Recurrence Developed More Than 9 Years after Radical Resection

A Case of Esophageal Cancer with Superior Mediastinal Lymph Nodes Recurrence Developed More Than 9 Years after Radical Resection

Local failure patterns after radical resection and adjuvant chemotherapy in patients with pN2 nonsmall-cell lung cancer: A retrospective analysis.

The patterns of local failure in stage pN2 nonsmall-cell lung cancer (NSCLC) patients undergoing radical resection and adjuvant chemotherapy are controversial. The sites of local failure were compared in subgroups of patients with relevant clinicopathologic features (e.g., location and size of primary lesions). Totally 75 patients with local failure after radical resection and adjuvant chemotherapy for pN2 NSCLC were included in the analysis. Thirty-seven (49.3%) patients had distant metastasis. The median duration from surgical resection to local failure was 11 months (range: 3-45 months). Sites with ≥10% failure rate in all subgroups based on the location of the primary lesions included 4R, 7, the ipsilateral hilum, and the stump. Additional sites with ≥10% failure rate included 2R, 2L, 4L, and 5 for lesions in the left upper lobe; 4L and 5 for lesions in the left lower lobe; and 2R and 3P for lesions in the right upper-middle lobe. Squamous cell carcinoma affected the stump failure rate compared to adenocarcinoma (56.3% vs. 18.0%, P = 0.003). Tumor diameter ≥5 cm affected the stump failure rate compared to tumor diameter < 5 cm (44.0% vs. 18.0%, P = 0.016). Skip N2 metastasis affected the ipsilateral hilum failure rate compared to nonskip N2 metastasis (7.5% vs. 31.4%, P = 0.008). For pN2 NSCLC patients undergoing radical resection and adjuvant chemotherapy, different lung lobes had different high-risk failure sites. Left lung cancer is prone to bilateral mediastinal lymph nodes recurrence, while right lung cancer mainly recurs with ipsilateral mediastinal lymph nodes. Moreover, the local failure patterns are influenced by pathological type, tumor size, and skip N2 metastasis.

P154 SAFETY AND ONCOLOGICAL EFFICACY OF BILATERAL RECURRENT LARYNGEAL NERVE LYMPH NODE DISSECTION AFTER NEOADJUVANT CHEMORADIOTHERAPY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Aim We sought to evaluate the safety and oncological efficacy of bilateral recurrent laryngeal nerve (RLN) lymph node dissection (LND) in patients with esophageal squamous cell carcinoma (ESCC) who had undergone neoadjuvant chemoradiotherapy (nCRT). Methods The need to dissect RLN lymph nodes in patients who had undergone nCRT is controversial. No data are currently available on the clinical utility and implications of RLN nodal dissection in nCRT-treated patients with esophageal cancer. We retrospectively examined the records of ESCC patients who were judged to be ycN-RLN(-) following nCRT. Patients were divided into two groups according to the extent of LND (standard two-field LND [STL group] versus total two-field LND [TTL group]). Only lower mediastinal and upper abdominal lymph nodes were removed in the STL group. In addition to the standard procedure, patients in the TTL group underwent resection of upper mediastinal lymph nodes located along the bilateral RLN. Using propensity score matching, 29 pairs were identified and compared with regard to perioperative complications, lymph node metastases rates, overall survival (OS), and disease-specific survival (DSS). Results No significant intergroup differences were identified in terms of in-hospital mortality and morbidity. Metastases to the RLN lymph nodes were identified in 20.7% (6/29) of TTL patients, being the only site of lymph node metastases in three of them. TTL was associated with lower upper mediastinal lymph node recurrence rate(6.5%) compared with STL (21.5%, p=0.134), although the overall recurrence rate was similar (STL, 44.8% versus TTL, 46.4%). No significant intergroup differences were also evident with regard to 3-year DSS and OS rates. Conclusions RLN LND can be safely performed in ESCC patients who had undergone nCRT, ultimately resulting in an improved local control and should be practiced as part of the surgical routine.

Short- and mid-term outcomes of robotic versus thoraco-laparoscopic McKeown esophagectomy for squamous cell esophageal cancer: a propensity score-matched study.

Controversy exists on the advantages of robotic McKeown esophagectomy (RME) versus thoraco-laparoscopic McKeown esophagectomy (TLME). The aim was to evaluate the short- and mid-term outcomes of RME and TLME in the treatment of patients with esophageal squamous cell carcinoma (ESCC). A consecutive series of 652 patients, 280 in RME and 372 in TLME, who underwent minimally invasive McKeown esophagectomy for ESCC at our department from November 2015 to June 2018 was analyzed. A propensity score-matched comparison with clinicopathological covariates was performed between the two groups. Complications were categorized based on the Esophagectomy Complications Consensus Group (ECCG) recommendation. To identify the recurrence, all patients with R0 resection were followed with a median follow-up period of 20.2months (range 1-33months). After propensity score matching, 271 patients were identified for each cohort. In the matched cohorts, two patients died within 90days in TLME, whereas no patients died in RME. RME was associated with similar intraoperative blood loss (P = 0.895), but with shorter surgical duration (244.5 vs. 276.0 min, P < 0.001), shorter thoracic duration (85.0 vs. 102.9 min, P < 0.001) and lower thoracic conversions (0.7% vs. 5.9%, P = 0.001). In spite of the similar results on total and thoracic lymph nodes dissection, RME yielded more lymph nodes along recurrent laryngeal nerve (4.8 vs. 4.1, P = 0.012), as well as the higher incidence of recurrent nerve injury (29.2% vs. 15.1%, P < 0.001) when compared to TLME. Tumor recurrence occurred in 30 patients and was locoregional only in 9 (3.5%) patients, systemic only in 17 (6.7%) patients, and combined in 4 (1.6%) patients in RME, while in 26 patients and was locoregional only in 10 (10.6%) patients, systemic only in 7 (2.8%) patients, and combined in 9 (3.6%) patients in TLME. RME was associated with a lower rate of mediastinal lymph nodes recurrence (2.0% vs. 5.3%, P = 0.044). Overall and disease-free survival was not different between the two cohorts (P = 0.097 and P = 0.248, respectively). RME was shown to be a safe and oncologically effective approach with favorable short- and mid-term outcomes in the treatment of patients with ESCC.

EP1.08-06 Postoperative Oligo-Recurrence of Non-Small Cell Lung Cancer

Postoperative recurrences of non-small cell lung cancer (NSCLC) are usually disseminated and systemic. The concept of oligo-recurrence, defined as a small number of new lesions at a distant site theoretically curable by local therapy, has recently been proposed for several cancers. The aim of this study was to clarify clinical features and outcomes of patients with postoperative oligo-recurrence of NSCLC. From 364 patients who underwent resection for NSCLC between January 2008 and December 2017 at our hospital. A total of 43 patients who developed recurrence were included in this study. Oligo-recurrence was defined as 1-2 loco-regional or distant recurrence lesions restricted to a single organ. Other recurrences were classified as poly-recurrence. Local therapy included surgery, stereotactic radiotherapy and radiotherapy. Oligo-recurrence was identified in 12 (27.9%) patients, mainly as a solitary recurrence (n=11, 91.7%) in regional lymph nodes (n=1), surgical stump (n=2), brain (n=5), lung (n=1), bone (n=2) and liver (n=1). Primary tumor histopathological types included 9 cases of adenocarcinoma, one case of squamous cell carcinoma, one case of pulmonary pleomorphic carcinoma and one case of large cell neuroendocrine carcinoma.The patients with oligo-recurrence had a longer time to recurrence than those with poly-recurrence (median: 23.5 months, 11.0 months). A case of mediastinal lymph node recurrence was performed radiation therapy. A case of surgical stump recurrence underwent lobectomy and other case was performed concurrent chemo-radiotherapy. 4 case of brain metastasis were underwent tumor resection and were performed stereotactic radiotherapy, one case of brain metastasis was performed stereotactic radiotherapy only. A case of lung metastasis underwent wedge resection and was used EGFR-TKI. A case of bone recurrence was performed radiation therapy and was used EGFR-TKI, other case was performed concurrent chemo-radiotherapy. A case of liver metastasis underwent tumor resection. 7 of 12 cases confirmed re-recurrence after local therapy. But 9 patients were alive between 30.4 and 110.0 months after local therapy, whereas three of 5 brain metastatic patients died between 24.9 and 71.8 months. The 5 year overall survival rates after local therapy were 81.5%. The presence of oligo-recurrence can predict a favorable prognosis in patients with NSCLC treated with aggressive local therapy.

Safety of thoracoscopic esophagectomy after induction chemotherapy for locally advanced unresectable esophageal squamous cell carcinoma.

Recent studies have reported that induction chemotherapy with docetaxel plus cisplatin and 5-fluorouracil (DCF) is an effective treatment for unresectable, locally advanced esophageal cancer. The aim of this study was to investigate the safety and feasibility of thoracoscopic esophagectomy (TE) after DCF for initially unresectable esophageal squamous cell carcinoma (ESCC). Twenty-three patients with initially unresectable T4 thoracic ESCC underwent TE after induction DCF. The neighboring organs with tumors were the tracheobronchus in nine patients, thoracic aorta in 13, and pericardium and diaphragm in three each (concurrent overlapping invasion occurred in five patients). The mean total operation time was 556.3 ± 107.2 minutes, and the mean time of the thoracic procedure was 258.9 ± 83.9 minutes. The mean total blood loss was 166.2 ± 117.8 mL, and the loss during the thoracic procedure was 33.5 ± 24.6 mL. All patients achieved complete R0 resection under TE. No conversions to open thoracotomy were performed. The postoperative morbidity rate was 34.8%. The postoperative hospital stay was 24.3 (range, 13-38) days. Five patients had recurrence: four had distant metastasis (lung, two; liver, three; and one with overlap), and one had mediastinal lymph node recurrence. No local recurrence was noted at the site of the primary T4 tumor. TE was safely performed in 23 patients after DCF therapy for locally advanced unresectable ESCC. Induction DCF, followed by TE, could be an alternative treatment for unresectable T4 ESCC.

Simultaneous Integrated Boost for Mediastinal Lymph Node Recurrence After Radical Surgery of Esophageal Cancer

Simultaneous Integrated Boost for Mediastinal Lymph Node Recurrence After Radical Surgery of Esophageal Cancer

Prognostic significance of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography-derived metabolic parameters in surgically resected clinical-N0 nonsmall cell lung cancer.

Our aim was to assess the significance of metabolic positron emission tomography (PET) parameters for the prediction of occult mediastinal lymph node metastasis (OLM) and recurrence in patients with clinical-N0 nonsmall cell lung cancer (NSCLC) after surgical resection and lymph node dissection. We evaluated 98 patients with NSCLC [52 adenocarcinoma (ADC), 46 squamous cell carcinoma (SQCC)] who had undergone initial/preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT). Eligibility criteria for participation were clinically staged as N0 and no FDG uptake in mediastinal lymph nodes on preoperative PET/CT. Clinicopathological characteristics and the diagnosis of recurrence were obtained by reviewing the hospital records. Metabolic parameters [maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume (MTV), total lesion glycolysis] were determined on F-FDG PET/CT images. The association of metabolic parameters with OLM and recurrence was assessed. OLM was found in 26 (26.53%) patients. T-stage, central location, and lymphovascular invasion were associated with OLM (respectively, P=0.007, 0.011, <0.001). None of the metabolic parameters was associated with OLM. Metabolic parameters of the tumor were significantly higher in patients with recurrence when the cohort was evaluated as a whole (P=0.002, 0.005, 0.016, and 0.004, respectively). In particular, there was a significant association between recurrence and tumor size, grade, stage, MTV (P<0.001), and TLG (P<0.001) in ADC. This association was not found in SQCC. Multivariate analysis showed that MTV was an independent prognostic factor for recurrence and associated with disease-free survival. Metabolic parameters of the primary tumor on preoperative F-FDG PET/CT could not predict OLM in patients with clinical-N0 NSCLC. MTV was an independent risk factor for recurrence in ADC, but not in SQCC.

Definitive radiotherapy for hilar and/or mediastinal lymph node metastases after stereotactic body radiotherapy or surgery for stage I non-small cell lung cancer: 5-year results.

The optimal treatment for hilar or mediastinal lymph node (LN) recurrence developing after stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer remains unclear. This study evaluated 5-year results of radiotherapy in such patients in comparison with those for postoperative LN metastases. Between 2004 and 2013, 27 patients with hilar and/or mediastinal LN metastases without local recurrence and distant metastasis after SBRT (n = 14) or surgery (n = 13) were treated with definitive conventional radiotherapy. The median total dose for treating metastatic LN was 60Gy for the post-SBRT group and 66Gy for the post-surgery group. The median follow-up for the 5 surviving patients was 62months. The overall survival, cause-specific survival, progression-free survival, and local control rates at 5years after mediastinal irradiation were 14%, 45%, 21%, and 58%, respectively, for the 14 patients in the post-SBRT group. These rates were 36%, 45%, 39%, and 92%, respectively for the post-surgery group (p = 0.066, 0.64, 0.38, and 0.41, respectively). Four patients in the post-SBRT group survived 3 or more years (range 36-92months) after mediastinal irradiation. A proportion of patients in both groups achieved long-term survival by conventional radiotherapy.

PS02.030: CLINICAL COURSE OF PATIENTS WITH COMPLETE RESPONSE BY CHEMORADIOTHERAPY FOR LOCALLY ADVANCED ESOPHAGIEAL CANCER

Abstract Background Definitive chemoradiotherapy (dCRT) is one of the treatment strategies for patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). In this report, we investigated the timing, pattern of recurrence, and prognosis in patients with LA-ESCC who achieved clinical complete response (cCR) following dCRT. Methods dCRT was performed for 71 patients with LA-ESCC from April 2006 and December 2017. We retrospectively examined the clinical records of 27 patients (38%) with ESCC who achieved cCR following dCRT assessed by the Response Evaluation Criteria in Solid Tumors (RECIST). These patients were classified into two groups: 19 patients (Group A) who did not recognize recurrence thereafter and 8 cases (Group B) who were confirmed to have recurred until Deccember 2017. Clinicopathological features and clinical course for two groups were examined. Results Clinical stages before treatment were cT1/2/3/4 = 7/3/6/3 cases, cN0/1/2/3 = 8/3/6/2, cM0/1 = 18/1 and cStage I/II/III/IV = 6/4/6/3 in Group A, and cT1/2/3/4 = 1/3/2/2, cN0/1/2/3 = 1/2/4/1, cM0/1 = 8/0, cStage I/II/III/IV = 1/0/5/2 in Group B, respectively. Patients in Group B had more advanced cases than Group A. In group A, 16 out of 19 patients (84%) are still alive without recurrence and 3 have died because of hypopharyngial cancer, lung cancer, and senility, respectively. Double cancers were confirmed in 12 patients (63%) including 6 head and neck cancers. In Group B, the recurrences were confirmed at 7–26 months (Median: 12.5M) from the diagnosis of cCR. Six out of 8 patients (6/8:75%) had the recurrence of mediastinal lymph nodes. In Group B, 6 out of 8 cases (75%) confirmed death, and the period from recurrence to death was 5–18 months (median: 9.5M). Conclusion After cCR was obtained by dCRT, recurrence was observed in 8/27 cases (29.6%) in about 13 months. In patients with recurrence, 75% of patients had mediastinal lymph node recurrence and had poor prognosis of about 10 months. Also in patients without recurrence, double cancers were observed in 12/19 cases, suggesting the importance of surveillance for the purpose of 2nd primary cancer screening. Disclosure All authors have declared no conflicts of interest.