Allen, Mark S.

e19013 Background: Mutation profiling to assess for potentially druggable mutations in NSCLC is being offered at an increasing number of cancer centers throughout North America and internationally. Although data continue to accumulate for the potential value of mutation testing in designing chemotherapeutic regimens, the treatment impact of obtaining information beyond assessment of EGFR and ALK status remains unclear. How best to obtain and clinically utilize these data, including information from exome and whole genome sequencing, also remains unclear. Methods: Patients were reviewed electronically in a multidisciplinary conference regarding indications for testing and results of mutation profiling from various methods, including the mass-spec based LungCarta test, targeted NexGen sequencing, exome, and whole genome sequencing. Outcomes of the multidisciplinary review were communicated back to treating physicians. Results: Mutation testing was performed on 200 patients using a variety of approaches. The majority (>150) were surgically resected stage I and II tumors. Mutations in at least 1 major cancer driver gene, including EGFR, KRAS, MET, BRAF and PIK3CA, were found in 47% of all patients tested. EGFR mutations were present in 14.8% of patients tested, KRAS 21.3%, BRAF 2.6%, PIK3CA 3.2%, and MET 4.5%. A total of 8 patients underwent either exome or whole genome sequencing. A limited number of patients (<10) had mutation results that impacted treatment decisions from this cohort. Conclusions: Mutation profiling can influence treatment decisions in NSCLC, but at a low frequency. The role of exome and or whole genome sequencing for patients with NSCLC is evolving and remains undefined.

7555 Background: Lymph node status is a major determinant of stage and survival in patients with lung cancer; however, little information is available about the yield of a mediastinal lymphadenectomy done at the time of pulmonary resection. Methods: The ACOSOG Z0030 trial is a prospective, randomized trial of mediastinal lymph node sampling versus complete mediastinal lymphadenectomy during an operation for early stage lung cancer. Total enrollment from July 1999 to February 2004 was 1,111 patients, of which 1,023 were eligible and/or evaluable. There were 524 patients who underwent complete mediastinal lymph node resection after randomization to this arm that were declared eligible and/or evaluable with lymph node data available. The number of lymph nodes examined from each station was collected beginning in January 2002. Prospectively collected data from these patients was analyzed to determine the number of lymph nodes obtained. Results: Median age was 67 (range 37–87) and 267 (52%) were men. Histology was squamous cell in 141 (27%), adenocarcinoma in 227 (44%), large cell in 22 (4%), bronchoavelolar in 32 (6%) and other non-small cell in 99 (19%). There were 317 right sided cancers and 207 left sided cancers. For lymphadenectomy for cancers in the right lung the yield from station 2R was a median of 2 lymph nodes (range 1 to 15), station 4R was 2 (1 –17), station 7 was 2 (1–24), station 8 was 1 (1–5), station 9 was 1 (1–6) and station 10R was 1 (1–10). For lymphadenectomy for cancers on the left side the yield from station 2L was 2 (1–4), station 4L was 1 (1–12), station 5 was 2 (1–18), station 6 was 2 (1–11), station 7 was 2 (1–16), station 8 was 1 (1–3), station 9 was 1 (1–8) and 10L was 2 (1–12). The total number of lymph nodes or fragments obtained for right sided cancers was a median of 13.5 (range 1 to 56) and for left sided tumors 15 (range 4 to 81). Conclusions: Although high variability exists in the actual number of lymph nodes obtained from various nodal stations, a complete mediastinal lymphadenectomy should obtain one or more lymph nodes from each mediastinal station. Adequate mediastinal lymphadenectomy should include exploration and remove of lymph nodes from stations 2R, 4R, 7, 8, and 9 for right sided cancers and stations 4L, 5, 6, 7, 8 and 9 for left sided cancers. No significant financial relationships to disclose.

Abstract Abstract 4168 Background: Primary Pulmonary MALT lymphoma represents 15–20% of Extranodal Marginal Zone Lymphomas of Mucosa Associated Lymphoid Tissue (MALT). In contrast to the more common gastric MALT lymphoma, natural history, prognosis and treatment outcomes for primary pulmonary MALT lymphoma are not well defined. Herein, we report a single institution experience. Methods: Consecutive patients with primary pulmonary MALT lymphoma registered in the Mayo Clinic Lymphoma Database, which includes all consenting patients with lymphoma seen at Mayo Clinic Rochester, were reviewed for clinical features, treatment outcome progression free survival (PFS) and overall survival (OS). The pathology for all patients was centrally reviewed by hematopathologist and the diagnoses were based on WHO lymphoma classification criteria. PFS and OS were assessed using the Kaplan–Meier method and the Cox proportional hazard model was used to assess the impact of variables on PFS and OS. Results: Between December 1986 and June of 2009, ninety-seven patients with primary pulmonary MALT lymphoma were enrolled. The median age at diagnosis was 63 years (range 31–87). There were 43 (44%) males. The initial presentation was a unilateral pulmonary lesion (n=47, 48%), bilateral pulmonary lesions (n=41, 42%), and pulmonary lesion with intrathoracic lymphadenopathy (n= 4, 4%). Bone marrow involvement and presence of B symptoms were 4, 4% and 5, 5%, respectively. International Prognostic Index (IPI) was 0–1, 2–3 and 4–5 in 69, 25 and 1 patient(s) respectively. The median follow-up was 10.4 years. The estimated median OS was 13. 6 years and the median PFS was 5.5 years (Figure). In a multivariate analysis, age >60 (p=0.02) and ECOG PS>2 (p=0.01) were associated with shortened survival. The IPI and age adjusted IPI were not predictive of overall survival. The treatment outcomes for the most common treatment modalities are summarized in the Table below. The median PFS of the 38% of patients who had a complete surgical resection was excellent at 11.2 years; whereas for observed patients with residual disease after biopsy was 3.2 years. Only 8 patients received single agent rituximan with relatively low response rate. Summary: The prognosis of primary pulmonary MALT lymphoma is favorable, with a median survival of over 13 years. In patients with resectable disease, surgery alone is associated with excellent disease control. Further prospective studies are needed to define the optimal treatment of primary pulmonary MALT lymphoma. Disclosures: No relevant conflicts of interest to declare.

Background: Oncologic sternectomy results in complex defects where preoperative planning is paramount to achieve best reconstructive outcomes. Although pectoralis major muscle flap (PMF) is the workhorse for sternal soft tissue coverage, additional flaps can be required. Our purpose is to evaluate defects in which other flaps beside PMF were required to achieve optimal reconstruction. Methods: A retrospective review of consecutive patients at our institution who underwent reconstruction after sternal tumor resection was performed. Demographics, surgical characteristics, and outcomes were evaluated. Further analysis was performed to identify defect characteristics where additional flaps to PMF were needed to complete reconstruction. Results: In 11 years, 60 consecutive patients were identified. Mean age was 58 (28–81) years old, with a mean follow-up of 40.6 (12–64) months. The majority were primary sternal tumors (67%) and the mean defect size was 148 cm2 (±81). Fourteen (23%) patients presented with postoperative complications, and the 30-day mortality rate was 1.6%. In 19 (32%) cases, additional flaps were required; the most common being the rectus abdominis muscle flaps. Larger thoracic defects (P = 0.011) and resections involving the inferior sternum (P = 0.021) or the skin (P = 0.011) were more likely to require additional flaps. Conclusions: Reconstruction of oncologic sternal defects requires a multidisciplinary team approach. Larger thoracic defects, particularly those that involve the skin and the inferior sternum, are more likely to require additional flaps for optimal reconstruction.

Abstract Background Pneumatosis intestinalis has long been a marker of advanced bowel ischemia and prompts urgent laparotomy. In post-operative settings, the presence of pneumatosis represents a significant management dilemma. We share a case-series of post-esophagectomy patients with pneumatosis intestinalis and no corollary intra-abdominal pathologic findings on re-exploration. Methods January 2000 to December 2017, 1760 patients underwent Ivor-Lewis esophagectomy or gastrectomy with jejunostomy-tube placement. Charts were reviewed retrospectively to identify patients with pneumatosis intestinalis discovered in the post-operative period. Demographic data, operative details and postoperative course were reviewed including incidence and details of re-exploration. Results Eleven patients met inclusion criteria. Nine were male (81.8%) and mean age was 69 years. All patients had radiographic confirmation of pneumatosis intestinalis and in many cases portal venous gas (Figure 1). Clinical course was variable without discernable trends in vitals or laboratory values. Development of significant postoperative ileus along with delivery of enteral tube feeds through a jejunostomy tube preceded development of the pneumatosis in all patients. Nine patients were re-explored and none had evidence of bowel ischemia. Conclusion The finding of pneumatosis intestinalis in the post-operative setting can be alarming and pose a management dilemma. With the advent of improved and readily available imaging, there has been an increase in findings that have no corollary physical symptomatology. In this series of patients, despite dramatic radiographic findings, none had ischemic bowel. Pneumatosis intestinalis alone in patients who have undergone esophagectomy should not be considered an indication for emergency re-exploration. Disclosure All authors have declared no conflicts of interest.

Abstract Background The purpose of this study was to evaluate the survival difference in clinical T2N0 esophageal cancer patients receiving neoadjuvant chemoradiotherapy (CRT) vs. upfront surgery. Methods Between 1/1/1995 to 12/31/2012, a prospectively maintained database was used to identify patients with cT2N0 esophageal adeno- and squamous cell carcinoma. Exclusion criteria included: lack of endoscopic esophageal ultrasonographic (EUS) staging, incomplete resection, and prior treatment with endoscopic mucosal or submucosal resection. Cox-proportional hazard ratios were used to compare the primary outcomes of overall (OS) and disease-free survival (DFS). Secondary outcomes included: rate of postoperative complications, rate of pathologic upstaging/response, and induction/adjuvant treatment completion rate. Pre-hoc subgroup analysis compared pathologically upstaged patients receiving upfront surgery followed by adjuvant chemotherapy to those treated with neoadjuvant CRT. Results A total of 161 cT2N0 esophageal cancer patients were identified based on EUS staging. Upfront surgery was offered to 134 patients (83%), with 27 patients (17%) receiving induction CRT. Univariate analysis did not demonstrate any significant baseline differences between the two groups. In the upfront surgery group, 53 (39.6%), 28 (20.9%) and 53 (39.6%) patients were pathologically down-staged, accurately staged and upstaged respectively. Upstaging was higher in the upfront surgery group (53/134, 39.6% vs. 4/27, 14.8%; P = 0.02), while 11/27 (40.7%) patients receiving neoadjuvant CRT demonstrated complete pathologic response. Of those eligible for adjuvant chemotherapy, only 21/55 (38.2%) received treatment. In the neoadjuvant CRT group, 51.9% completed all planned therapy, compared to 23.6% of patients treated with upfront surgery followed by adjuvant chemotherapy (P = 0.01). Cox proportional hazard ratio did not demonstrate an advantage to induction CRT in terms of OS (HR = 1.64, P = 0.43) or DFS (HR = 1.36, P = 0.69). In general, patients with pathologic upstaging had worse OS (HR = 2.73, P = 0.001) and DFS (HR = 4.18, P = 0.003). Conclusion EUS was only accurate in staging T2N0 patients in 20.9% of cases. While neoadjuvant CRT did not confer a survival advantage, these results likely reflect the low number of patients being referred for induction therapy. Neoadjuvant CRT was however associated with lower rates of pathologic upstaging and higher rates of treatment completion. Further research should evaluate the survival outcomes in pathologically upstaged cT2N0 patients not receiving neoadjuvant therapy. Disclosure All authors have declared no conflicts of interest.

Abstract Background The objective of this study was to analyze the induction therapy regimens employed since publication of CROSS Trial in patients treated with locally advanced EGJ cancer in terms of toxicity, complications, survival and recurrence. Methods Retrospective chart review all patients in single institution prospective database who had neoadjuvant CRT→Surgery 2012–2015. Complications during CRT and after surgery graded using National Cancer Institute CTCAE. Cox-proportion hazard ratios were used to compare the primary outcomes of overall survival (OS) and disease-free survival (DFS). Results 288 patients, 237 men and 51 women were identified. 246 were adenocarcinoma, 38 squamous cell carcinoma, and 4 had other histologic types. 4 distinct neoadjuvant regimens were observed: 50.4 Gy radiation with 5-fluorouracil and cisplatin (N = 22), CROSS regimen (41.4 Gy with carboplatin & paclitaxel) (N = 44), 50.4 Gy with carboplatin and paclitaxel (N = 152), and ‘Other’ which include 27 distinct regimens (N = 70). There were no differences in treatment related complications or postoperative complications between regimens. There was no difference in pathologic complete response rate, OS, or DFS between regimens. Conclusion Since the publication of the CROSS Trial, there is a significant heterogenity in the neoadjuvant chemoradiation treatment regimen employed for patients with locally advanced EGJ tumors. Does not appear to be any differences in treatment related complications or postoperative complications between regimens. There was also no difference in pCR, overall survival or disease-free survival. Disclosure All authors have declared no conflicts of interest.