A novel stratification of mesenteric mass involvement as a predictor of challenging mesenteric lymph node dissection by minimally invasive approach for ileal neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: We classified the extent of mesenteric mass (MM) involvement that predicts challenging mesenteric lymph node dissection (mLND) by minimally invasive surgery (MIS) for ileal neuroendocrine tumors (i-NETs). METHODS: Patients who underwent surgery for i-NETs were retrospectively reviewed. MM involvement was classified as region-0: no MM; region-1: >2 cm from the origins of the ileocolic artery/vein; region-2: ≤2 cm from the origins; and region-3: more proximal superior mesenteric artery/vein. Logistic regression analysis was used to evaluate the predictive value of MM regions for gross positive mesenteric margin (mR2) and/or conversion among the MIS cohort. The open surgery cohort was used as a reference for mR2 rates. RESULTS: Of 108 patients, 83 patients (77%) underwent MIS. MMs in region-2 and region-3 were independent risk factors for mR2 and/or conversion (odds ratio [95% confidence interval]: 4.25 [1.17-16.4] and 8.51 × 107 [11.0-], respectively, against regions-0 and 1]. mR2 rates of MIS and open surgery cohorts per region did not differ significantly (4% and 7% for regions-0 and 1; 17% and 25% for region-2; and 100% and 83% for region-3). CONCLUSIONS: The novel stratification of MM regions was predictive of challenging mLND by MIS. Surgeons should have a low threshold for conversion for MMs in proximal regions.

Residual tumor volume discriminates prognosis after surgery for neuroendocrine liver metastasis.

BACKGROUND AND OBJECTIVES: We developed objective measurements of preoperative and residual tumor volume, and debulking rate, to evaluate their prognostic value for neuroendocrine liver metastasis (NELM). METHODS: Seventy-three patients who underwent surgery for NELM were analyzed retrospectively. Indices of preoperative and postoperative residual tumor volume (pre-volume index [VI] and post-VI) were calculated as the sum of the cubes of individual tumor diameters on preoperative and postoperative imaging, respectively. The debulking rate (%) was calculated as 100 - 100 × post-VI/pre-VI. The classification and regression trees method was used to classify pre-VI and post-VI. RESULTS: Overall survival (OS) was discriminated by preoperative tumor volume (5-year OS rates, 87.8% for low pre-VI and 60.1% for high pre-VI; P = .037) and residual tumor volume (5-year OS rates, 88.1% for low post-VI and 24.8% for high post-VI; P < .001). In contrast, debulking rates of 100%, ≥90%, and <90% did not discriminate OS (5-year OS rates, 88.0%, 61.9%, and 58.9%, respectively, not significant). In multivariate analysis, residual tumor volume (high post-VI, hazard ratio, 6.40; 95% confidence interval, 1.45-32.3) was an independent prognostic factor for OS. CONCLUSIONS: Objective measurement of tumor volume demonstrates that residual tumor volume is prognostic after surgery for NELM.

Prognostic impact of a large mesenteric mass >2 cm in ileal neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: Ileal neuroendocrine tumors (i-NETs) frequently metastasize to mesenteric lymph nodes and the liver. Regional lymphadenopathy is associated with desmoplasia of the mesentery forming a large mesenteric mass (LMM). Although the latest American Joint Committee on Cancer TNM staging (8th edition) defined LMM >2 cm as N2, the prognostic impact of LMM is ill-defined. We evaluated whether LMM is prognostic for patients with i-NETs. METHODS: This single-institution, retrospective cohort study included 106 patients who underwent resection of i-NETs between 2007 and 2018. Overall survival (OS) and liver progression-free survival (LPFS) were compared between patients with and without LMM. RESULTS: LMM was present in 66 patients (62%) and was not associated with the presence or absence of liver metastasis (P = .969) or the extent of liver involvement (P = .938). OS and LPFS differed significantly between patients with and without LMM (5-year OS rates of 64.8% and 92.9%, respectively, P = .011; 3-year LPFS rates of 45.3% and 67.5%, respectively, P = .025). In multivariate analysis, LMM was an independent prognostic factor for both OS (hazard ratio: 4.69, 95% confidence interval: 1.63-17.6) and LPFS (1.99, 1.08-3.88). CONCLUSION: LMM >2 cm is prognostic for OS and LPFS and represents aggressive tumor biology.

Real-World Treatment Patterns and Clinical Outcomes in Advanced Gastrointestinal Neuroendocrine Tumors (GI NET): A Multicenter Retrospective Chart Review Study.

BACKGROUND: We assessed treatment patterns and outcomes of patients with advanced gastrointestinal (GI) neuroendocrine tumors (NET) at four large tertiary referral centers in the U.S. PATIENTS AND METHODS: We performed a retrospective chart review of patients aged ≥18 years at advanced GI NET diagnosis, treated between July 2011 and December 2014. Index date was the histologically confirmed diagnosis date of locally advanced/metastatic GI NET. Data included baseline characteristics, treatment patterns, progression, death, and GI NET-related health care resource utilization from index date through last contact or death. Time-to-event analyses, including treatment discontinuation, progression, and overall survival (OS), were performed using Kaplan-Meier analysis. RESULTS: We identified 273 patients; 156 (57%) had primary ileum NET, and 174 (64%) had functional NET. First-line treatments included somatostatin analog (SSA) alone (89%) or in combination (2%), liver-directed therapy (LDT; 8%), and cytotoxic chemotherapy or interferon (2%). One hundred fifty-five patients continued with second-line therapy, including SSA alone (17%) or in combination (75%, with 3% combined with peptide receptor radionuclide therapy), LDT (4%), and other treatments (3%). Median time (months) to first-line discontinuation was 154.0 for SSAs and 3.8 for cytotoxic chemotherapy. Overall median time to investigator-assessed progression following treatment initiation was 30.3 months. Median OS (months) following first-line initiation was 151.8 for all patients and 178.9 for first-line SSA. CONCLUSION: Our study illustrates the common use of SSAs in both first-line and subsequent treatment of patients with GI NETs, as well as the relatively long survival durations and multiple additional treatments received by patients with this condition. Treatment pattern assessment at later times, following approval of newer treatments, is warranted. IMPLICATIONS FOR PRACTICE: This study, assessing treatment patterns over a period of up to 30 years, showed that SSAs, LDT, cytotoxic chemotherapy, and interferon are common treatments for advanced GI NETs. SSAs alone or in combination with other treatments were the most frequent therapy in first and subsequent lines. Patients in this study remained on SSAs long-term, with median treatment duration of 12.8 years in first line. Treatment patterns should be assessed beyond this study's time period, given recent U.S. Food and Drug Administration approvals for additional treatments for GI NET, which will likely be incorporated in the continuum of care of patients.

Treatment Patterns and Clinical Outcomes in Advanced Lung Neuroendocrine Tumors in Real-World Settings: A Multicenter Retrospective Chart Review Study.

BACKGROUND: Using data from four tertiary referral centers in the U.S., we assessed real-world treatment patterns and clinical outcomes of patients with advanced lung neuroendocrine tumors (NETs). SUBJECTS, MATERIALS, AND METHODS: We performed a retrospective chart review of adult patients with locally advanced/metastatic (typical/atypical) lung NETs treated between July 2011 and December 2014. Index date was histologically confirmed typical/atypical carcinoid tumor diagnosis date. Data included baseline characteristics, treatment patterns, progression, death, and lung NET-related health care resource use from index date through last contact/death. Time to treatment discontinuation and first progression, time from first to second progression, and overall survival (OS) were estimated using Kaplan-Meier analysis. RESULTS: We identified 83 patients; 19 (23%) had functional NET. First-line treatments included somatostatin analogs (SSAs) alone (56%) or in combination with other therapies (6%), cytotoxic chemotherapy (20%), external beam radiation therapy (EBRT) (9%), liver-directed therapy (LDT) (4%), and everolimus/other (5%). Sixty patients had second-line therapy including SSA alone (18%) or in combination (40%), cytotoxic chemotherapy (17%), everolimus (12%), LDT (7%), EBRT (3%), and other treatments (3%). Median time (months) to first-line discontinuation were as follows: SSAs, 43.3; cytotoxic chemotherapy, 3.6. Overall median time (months) to investigator-assessed progression following treatment initiation was 12.4. Median OS (months) following treatment initiation was 66.4 for all patients and 81.5 for patients receiving SSAs. CONCLUSION: SSAs, alone and in combination, are common treatments for advanced lung NETs. Patients have additional treatment options and relatively long survival compared with patients with other advanced cancers. Treatment pattern assessment following approval of newer treatments is needed. IMPLICATIONS FOR PRACTICE: Somatostatin analogs (SSAs), cytotoxic chemotherapy, EBRT, liver-directed therapy, and targeted therapies are common treatments for locally advanced/metastatic (typical/atypical) lung neuroendocrine tumors (NETs). SSAs alone or in combination with other treatment modalities were the most common first- and second-line therapy, followed by cytotoxic chemotherapy. Patients continued treatment with SSAs long-term with median treatment duration of 43 months. Median overall survival was 66 months following initiation of first-line therapy for all patients. Treatment pattern assessment beyond the time period of this study is needed given recent U.S. Food and Drug Administration approvals for additional treatments for lung NETs that will likely be incorporated in the treatment landscape.