Examination of factors associated with lymph node metastases in lung carcinoids: Results from a single institution retrospective cohort study.

BACKGROUND: Well-differentiated lung neuroendocrine tumors (NETs), also known as typical and atypical carcinoids, have a decreased incidence of lymph node (LN) and distant metastases compared to poorly differentiated lung NETs. We aimed to (i) examine the clinicopathologic features associated with LN involvement in lung carcinoids and (ii) describe the postoperative management of patients with LN metastases. METHODS: We identified 98 patients who underwent surgical resection and lymph node sampling at Stanford University. We assessed the following and used AJCC staging version 7: clinical features (age, sex, race, prior malignancy, smoking history), tumor features (functional syndrome, histology, size, location, laterality), pre-operative workup performed (imaging and suspicion of LN metastases), surgery (nodes and stations sampled, margin status, surgical approach, and type of surgery), and recurrence outcome. These features were examined between patients with and without LN metastases using the Wilcoxon test (continuous variables) and Fisher's exact test (categorical variables). RESULTS: 87 patients (89%) had typical carcinoid and 11 patients (11%) had atypical carcinoid. 17 patients were found to have at least one positive lymph node, with 11 having N1 disease and 6 having N2 disease. In the univariable analysis, patients with lymph node disease were more likely to have recurrence of lung carcinoid (29% vs. 6%, p=0.01). In the multivariable logistic regression, there was a trend towards performance of preoperative SSTR imaging and lymph node involvement (OR = 3.06, p=0.07). No patients received adjuvant therapy. CONCLUSION: We found a trend for the performance of SSTR imaging and association of lymph node metastases in both univariable and multivariable analysis. A large proportion (41%) of patients with lymph node positive disease had < 2 cm tumors. This suggests the potential importance of incorporating SSTR imaging into routine practice and not restricting the use of this staging modality in patients with small tumors.

Predicting Response to Immunotherapy by Evaluating Tumors, Lymphoid Cell-Rich Organs, and Immune-Related Adverse Events Using FDG-PET/CT.

PURPOSE: To investigate whether the evaluation of tumors, lymphoid cell-rich organs, and immune-related adverse events (IRAE) with F-FDG PET/CT can predict the efficacy and outcome of immunotherapy. METHODS: Forty patients who underwent F-FDG-PET/CT scans before and after therapy with immune checkpoint inhibitors from December 2013 to December 2016 were retrospectively enrolled (malignant melanoma, n = 21; malignant lymphoma, n = 11; renal cell carcinoma, n = 8). SUVmax of the baseline and first restaging scans were evaluated in tumors, spleen, bone marrow, thyroid and pituitary glands, and were correlated to best overall response in the first year after therapy; IRAE-affected areas were also evaluated. RESULTS: Interval change between the baseline and first restaging scans showed that patients with a clinical benefit had a significant decrease in tumor parameters (P < 0.001). All patients with an increase of SUVmax in the thyroid of more than 1.5 (n = 5) on the first restaging scan had a complete response (CR) in 1 year. Patients with CR within 1 year (n = 22) were significantly associated with a favorable long-term outcome (P = 0.002). Nine patients with IRAE findings had CR at final evaluation. Among IRAE, thyroiditis was seen significantly earlier than arthritis (P = 0.040). CONCLUSIONS: The decrease of tumor parameters at early time-point PET scans was seen in patients with immunotherapy who had clinical benefit within 1 year. PET-detectable IRAE was useful for prediction of a favorable outcome. Early development of thyroiditis may particularly represent an early response indicator to immunotherapy.