Citations

e21575 Background: The clinical significance of brain metastases in patients with bronchopulmonary neuroendocrine (NE) tumors is unknown; we therefore conducted a population based analysis to evaluate the implications of brain metastases in these patients. Methods: The NCDB database was queried to identify patients with stage IV bronchopulmonary NE tumors treated between the years of 2004-2012. Patients were split into two groups based on the presence of brain metastases at diagnosis and survival probabilities with multivariate models were performed. Results: A total of 7,725 patients with Stage IV bronchopulmonary NE tumors were identified. The histological subtypes studied in this cohort were NE carcinoma (65.4%), large cell NE carcinoma (30.5%), typical carcinoid (2.8%) and atypical carcinoid (1.3%) . The patients included in this study were mainly white (86.4%) men (56.8%) with a median age of 67 years who had liver (9.5%), bone (6.2%) and brain (5.9%) metastases at diagnosis. The median overall survival (OS) of the cohort was 5.59 (95% CI: 5.4-5.8) months, but when OS was stratified by histological subtype it was significantly better in patients with typical carcinoid (table). In the whole cohort, the median OS did not differ between patients with and without brain metastases (5.55 vs. 5.68; p = 0.24). However, a sensitivity analysis by histology showed that the presence of brain metastases worsen the median OS of patients with typical carcinoid only (15.1 vs 4.6, p = 0.04). An adjusted multivariate analysis restricted to patients with brain metastases showed that administration of systemic chemotherapy (HR:0.5; 95% CI:0.35-0.72, p < 0.001) and resection of distant metastases (HR:0.5; 95% CI:0.29-0.88, p = 0.017) were the two most powerful independent prognostic factors. Conclusions: The presence of brain metastases negatively impact survival of patients with typical carcinoids but not in those with the other histological subtypes included in this study. Staging MRI should be strongly considered at diagnosis in patients with bronchopulmonary NE tumors, due to the sizable proportion of these patients presenting with brain metastases and also due to its prognostic value in a subset of this population. [Table: see text]

e21007 Background: There is a lack of data to guide the management of resectable bronchopulmonary carcinoid tumors (BCTs). Methods: The NCDB database was retrospectively reviewed to analyze the roles of surgery, chemotherapy and radiation. Patients with a diagnosis of clinically staged T1-2/N0-1 typical carcinoid (TC) and atypical carcinoid (AC) between 2004-2012 were included. Kaplan-Meier methods and multivariable analysis were performed. Results: A total of 2148 patients (TC 1874 & AC 274; T1/1648 & T2/500) were identified. The median age was 59 (range 18-89). There was a female (69.7%) and right lung (56.9%) predominance. Fifty-three patients received pneumonectomy, 68 chemotherapy, and 84 radiation therapy. The impact of age, histology (TC vs. AC), medical comorbidities (Charlson/Deyo score 0 vs. ≥1) and type of surgery [sublobar resection (SR) vs. lobectomy vs. lobectomy with mediastinal lymph node dissection (L/MLND)] were subsequently examined. AC, older age, and comorbidities were associated with shorter overall survival (OS) by both univariate and multivariable analysis. Patients who underwent lobectomy had longer OS (119 months) than those with SR (109 months) or L/MLND (115 months). However, this association was not significant by multivariable analysis with age incorporated as either a categorical ( < 60 vs. ≥60) or a continuous variable (Table). In the subgroup analysis of patients with T1, T2, TC and AC respectively, type of surgical resection was not significantly associated with OS by multivariable analysis. Conclusions: Patients with resectable BCTs have excellent OS. Atypical histology, older age, and comorbidities predicted inferior OS. There were insufficient data to support the use of perioperative chemotherapy or radiation therapy. Lobectomy was associated with prolonged OS by univariate analysis but this was not significant in the multivariable model, suggesting that SR is a reasonable approach for patients who cannot tolerate lobectomy. MLND did not seem to provide additional survival benefits. [Table: see text]

e16752 Background: Undifferentiated osteoclast-like giant cell carcinoma of the pancreas is an aggressive malignancy only described by a few case reports in the literature. In this study, we sought to better characterize this entity by examining patients seen at Mayo Clinic. Methods: This study identified patients with osteoclast-like giant cell carcinoma of the pancreas using Mayo Clinic databases (MN, AZ, FL) from the year 2000 to present. Patient demographics, genetic data, and treatment modalities were reviewed. Kaplan-Meier analysis was used to evaluate median overall survival (mOS) for the cohort as well as mOS and mPFS for treatment subgroups. Results: 15 patients were identified (9 female, 6 male). Median age at diagnosis was 59 years and mOS for all patients was 11.0 mos (95% CI 6.2-15.7 mos). 3 patients (20%) had metastatic disease at diagnosis with the liver being the most common site (n = 3). Metastatic disease was associated with significantly shorter OS (3.5 vs. 14.1 mos, p = 0.005; HR 7.98 [95% CI 1.43-44.4]) compared to locoregional disease (LRD). 4 patients underwent genetic testing. The most common mutation was CDKN2A (n = 3), followed by TP53 (n = 2) and KRAS (n = 2). 13/15 patients had detailed follow-up information. 6/7 patients undergoing chemotherapy received a gemcitabine-based regimen as first line: with capecitabine (n = 2), with nab-paclitaxel (n = 2), or as monotherapy (n = 2). 1 patient received FOLFIRINOX. In patients with LRD and adequate follow-up (n = 11), 8/11 underwent surgical resection and had longer OS compared to those without resection (17.0 vs. 8.4 mos, p = 0.09). No surgical patients received neoadjuvant chemotherapy. 5/8 received adjuvant chemotherapy, 2 did not undergo chemotherapy, and 1 was lost to follow-up after surgery. PFS from time of surgery was 15.3mos (95% CI 5.0-25.6mos). 6 patients (40%) were alive at time of analysis; all 6 underwent surgical resection. Conclusions: Osteoclast-like giant cell carcinoma of the pancreas is a rare malignancy with a poor prognosis, even when diagnosed at an early stage. OS for patients of all stages in this study was less than 1 year suggesting prognosis may be even worse than that of pancreatic adenocarcinoma. The optimal therapy remains unknown but most patients received similar chemotherapy as in adenocarcinoma. Patients with LRD amenable to surgical resection experienced a PFS over 1 year from surgery, possibly associated with OS benefit, however overall prognosis is poor. Further study is warranted on a larger scale to better understand disease course and treatment options.

e16702 Background: There are only a few reports examining the treatment patterns for poorly differentiated rectal/anal NEC. In this study, we sought to report treatment and survival outcomes for patients with NEC of the anus and rectum seen at Mayo Clinic. Methods: We identified patients with a primary NEC of the anus or rectum using Mayo Clinic databases (Minnesota, Arizona, Florida) from the year 2000 to present. NEC identified within polyps on colonoscopy was excluded from this study. Patients’ demographics were compiled. Kaplan Meier analyses were performed to evaluate overall survival (OS) for all patients, as well as subgroups with locoregional disease (LRD) and metastatic disease at diagnosis. Progression free survival (PFS) was also evaluated for patients with LRD treated with chemoradiation therapy (CRT). Results: 38 patients with NEC of the anus/rectum were identified with a median age of 55.5 years. 23 patients (61%) had metastatic disease at diagnosis and 15 (39%) had LRD. The most common site of metastasis was the liver (n = 20). Patients with metastatic disease at presentation had significantly shorter OS compared to patients with LRD (median OS 10.4 vs. 18.9 months, p = 0.039; HR 2.46, 95% CI [1.001-6.050]). 34 total patients received chemotherapy (ORR 11.8%), with platinum + etoposide (EP) being the most common first-line chemotherapy (n = 26). 10 of 15 patients with LRD received CRT (9 with EP and 1 with 5-FU) with median PFS of 6.3 months (95% CI 2.3-16.5 months), a 1-year PFS rate of 20%, and median OS of 18.6 months (95% CI 13.5-23.7 months). 2/10 received induction chemotherapy prior to CRT with 6/10 undergoing primary tumor resection (1 prior to CRT and 5 after CRT). Only 3 CRT patients were living at time of analysis (all underwent surgical resection), 2 without any active disease, 1 who achieved complete response with CRT then suffered recurrence and is still undergoing treatment. Conclusions: NEC of the anus and rectum is an aggressive malignancy with most patients experiencing metastatic disease at presentation and poor response to chemotherapy at all stages. Even those with LRD experience a very poor prognosis with OS of 18.9 months from diagnosis. For LRD, most patients underwent CRT with only a short-lived response (median PFS 6.3 months). Those achieving sustained response also underwent surgical resection. Overall, prognosis is poor for all stages and further study on a large scale is warranted to better characterize this rare, aggressive malignancy.

e16691 Background: Recent WHO classification of NET has defined high-grade well-differentiated NET (NET G3) as a distinct entity that is clinically different from neuroendocrine carcinoma. The optimal treatment for NET G3 has not been well-described. This study aims to evaluate NET G3 response to different treatment regimens. Methods: This is a retrospective study of NET G3 patients within the Mayo Clinic database (Arizona, Florida, and Minnesota). Patient demographics along with treatment responses and survival were assessed. Primary end points were progression-free survival (PFS) and objective response rate (ORR) by RECIST 1.1 criteria. Results: 71 patients with NET G3 were identified. Systemic treatment data was available in 30 patients who had a median age of 59.5 years at time of diagnosis. The primary tumor was most commonly pancreatic (73.3%). Ki 67 index was ≥55% in 26.7% of cases. 56.7% of cases had > 1 metastatic site. Treatment regimens included: capecitabine+temozolomide (CAPTEM) (n = 20), somatostatin analog (SSA) (n = 14), carboplatin/cisplatin+etoposide (EP) (n = 7), everolimus (n = 2), FOLFOX (n = 7), and lutetium Lu 177 DOTATATE (PRRT) (n = 10). CAPTEM was the most commonly used regimen (10 first-line, and 10 second-line) with ORR of 35%, disease control rate (DCR) of 65%, and median PFS of 9.4 months. The table summarizes the treatment data and responses rates for the various therapies used. Conclusions: Among NET G3 patients treated at Mayo Clinic, CAPTEM was found to be the most commonly used treatment with reasonable efficacy and disease control. Other treatment options include SSA, PRRT, FOLFOX, and EP. Prospective studies evaluating different treatments effects in NET G3 patients are needed to determine an optimal treatment strategy. [Table: see text]

4541 Background: Anti-VEGFR2 therapy (ramucirumab/paclitaxel [RAM/TAX]) and ICI are approved as 2nd- and 3rd-line therapy (Tx), respectively, for pts with mGEA. We unexpectedly saw durable responses in 2 pts on RAM/TAX after progression on an ICI trial (KN-059; PMID 29674442). We performed a pilot to examine the clinical activity of ICI followed by RAM/TAX. Then we retrospectively compared the outcomes of pts who received this serial Tx to pts who received RAM/TAX without prior ICI. Methods: All pts with mGEA at Mayo Clinic who received RAM/TAX (2014-19) were included (N = 87). Outcomes were best objective response rate (ORR: complete [CR] or partial response) per RECIST1.1, progression-free survival (PFS), duration of response (DOR), and overall survival (OS). Chi square and multivariate (MV) logistic and Cox regression were used. Results: 15 consecutive pts with measurable mGEA received ICI immediately followed by RAM/TAX after irRECIST progression. Most pts (95%) did not respond to ICI. Yet on RAM/TAX, 100% (15/15) had tumor reduction (range -8% to -100%) with an ORR of 73% (11/15), including 3 CRs. In these pts (who received ICI followed by RAMTAX), PFS on RAMTAX was longer than on last chemotherapy before ICI (12.3 vs 3.0 m, P < .001). Outcomes on RAM/TAX in these pts were significantly better than in pts who received RAM/TAX alone (see Table). Associations were strengthened after adjusting for total lines of Tx, line of Tx of RAM/TAX, age, and ECOG PS. Exploratory analysis of paired tumor biopsies collected pre-ICI and on RAM/TAX in a small subset revealed that the frequency of intratumoral immunosuppressive FOXP3+ Tregs decreased on RAM/TAX, whereas the frequency of antitumor CD8+ T cells was preserved. Conclusions: RAM/TAX immediately preceded by ICI was associated with significantly higher OS, ORR, and DOR than RAM/TAX alone, suggesting ICI may enhance efficacy of subsequent anti-VEGFR/taxane therapy. This novel sequence of therapy will be tested prospectively in a new randomized phase 2 trial (NCT04069273). [Table: see text]

AbstractOver the last 5 years, there have been more than 140 new drug approvals in the field of Oncology alone, all based on newly published clinical trials. These approvals have led to an ongoing change in clinical practice, offering new therapeutic options for patients. Therefore, it is important for healthcare providers to be able to appraise a clinical trial and determine its validity, understand its results, and be able to apply such results to their patients. In this guide, we provide a simplified approach tailored to practicing clinicians and trainees. The same concepts and principles apply to other medical specialties.