Sublobar Resection in the Treatment of Peripheral Typical Carcinoid Tumors of the Lung

Visual analysis of lung neuroendocrine tumors based on CiteSpace knowledge graph

Objective

The relevant literatures in the field of pulmonary neuroendocrine tumor were analyzed to understand the lineage, hot spots and development trends of research in this tumor.

Method

The Web of Science core collection was searched for English-language literature about neuroendocrine tumors of the lung published between 2000 and 2022. CiteSpace software was imported for visualization analysis of countries, institutions, co-cited authors and co-cited journals and sorting of high-frequency keywords, as well as co-cited references and keyword co-occurrence, clustering and bursting display.

Results

A total of 594 publications on neuroendocrine tumours of the lung were available, from 2000 to 2022, with an overall upward trend of annual publications in the literature. Authors or institutions from the United States, Italy, Japan and China were more active in this field, but there was little cooperation among the major countries. Co-cited references and keyword co-occurrence and cluster analysis showed that research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis and treatment was a current research hotspot. The keyword bursts suggested that therapeutic approaches might be a key focus of future research into the field for pulmonary neuroendocrine tumors.

Conclusion

Over these 20 years, research related to neuroendocrine tumors of the lung has increased in fervour, with research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis, and treatment being the main focus of research. Therapeutic treatments may be the future research trend in this field.

Prognosis of Unresected vs Resected Small Pulmonary Carcinoid Tumors

BACKGROUND

Previous studies have shown that overall survival after lung resection for pulmonary carcinoid tumors is favorable. It is unclear what the prognosis is for observation rather than resection for small carcinoid tumors.

METHODS

We queried the National Cancer Database to identify patients presenting with primary pulmonary carcinoid tumors between 2004 and 2017. We included patients with small (<3 cm) primary pulmonary carcinoids, who were observed or underwent a lung resection. To minimize confounding by indication, we used propensity score matching, while accounting for age, sex, race, insurance type, Charlson-Deyo comorbidity score, typical and atypical histology, tumor size, and year of diagnosis. We used Kaplan-Meier survival analyses to compare 5-year overall survival in the matched cohorts.

RESULTS

Of 8435 patients with small pulmonary carcinoids, 783 (9.3%) underwent observation and 7652 (91%) underwent surgical resection. After propensity score matching, surgical resection was associated with improved 5-year overall survival (66% vs 81%, P < .001). No significant difference in overall survival was found between wedge and anatomic resection (88% vs 88%, P = .83). In patients undergoing resection, lymph node sampling at the time of wedge and anatomic resection increased 5-year overall survival (90% vs 86%, P = .0042; 88% vs 82%, P = .04, respectively).

CONCLUSIONS

Surgical resection of small pulmonary carcinoids is associated with improved survival compared with observation. When surgical resection is performed, wedge and anatomic resection result in similar survival, and lymph node sampling improves survival.

A Competing Risk Model Nomogram to Predict the Long-Term Prognosis of Lung Carcinoid

BACKGROUND

The prediction of long-term, cancer-specific survival of lung carcinoid remains controversial. We aimed to build a prognostic model by using competing-risk analysis to predict the long-term, cancer-specific survival of lung carcinoid patients.

METHODS

Patients were retrospectively enrolled from the SEER database, and clinicopathological data were collected. Univariable and multivariable competing-risk analyses were conducted to identify prognostic factors. A competing-risk model and a nomogram were developed by using independent prognostic factors. The model was assessed by using concordance index and calibration curves.

RESULTS

A total of 2496 patients were enrolled, of which 267 (10.7%) died of diagnosed carcinoma; 316 (12.7%) died because of other reasons. The 5-year, 10-year, and 15-year cancer-specific survival of carcinoid patients were 91.35%, 86.60%, and 84.39%, respectively. Multivariable analysis demonstrated that increasing age, male, larger tumor size, higher N stage, M1, atypical carcinoid, and undergoing no surgery were independent risk factors. A competing-risk model based on the risk factors and a corresponding nomogram were developed. Concordance index of the developed model for 5-year, 10-year, and 15-year were 0.891, 0.856, 0.836 respectively in the training cohort and 0.876, 0.841, 0.819 respectively in the validation cohort after bootstrap adjustment. The calibration curves of 5-year, 10-year, and 15-year showed good agreement.

CONCLUSIONS

Increasing age, male, larger tumor size, higher N stage, M1, atypical carcinoid, and undergoing no surgery were independent risk factors. A competing risk model of excellent performance in predicting long-term survival was developed, and a nomogram was established.

Bronchial carcinoid tumors in children and adolescents - A report and management considerations from the German MET studies

OBJECTIVES

Bronchial carcinoid tumors (BC) are exceptionally rare in childhood, with an incidence of <0.2/1,000,000 per year. Typical low-grade BCs are distinguished from atypical, intermediate-grade BCs. Little is known about BCs in pediatric patients and management guidelines are missing. In this study, we explored characteristics and outcome of pediatric patients with BC prospectively registered with the Malignant Endocrine Tumor studies.

MATERIAL AND METHODS

We performed a retrospective multicenter study in children, adolescents, and young adults (aged 0-20 years) with BC reported to the German MET registry between January 1997 and December 2022. Data were last updated on 28 of February 2023.

RESULTS

Thirty-two patients were diagnosed at a median age of 15.0 years (range, 9.8-19.2). Atypical BCs (23.3%) were less frequent than typical, but more common than in adulthood. Lymph node metastases were present in 14.3% of cases (atypical BC: 28.6%, typical BC: 10.5%), distant metastases in one (3.1%) patient with atypical BC. 92.6% of patients were in complete remission after surgical resection (median follow-up: 2.7 years). The patient with metastatic spread and one patient with atypical BC and multiple recurrences were on treatment at last follow-up. 5-year event-free survival of typical BC was 100% and 83.3% in atypical BC.

CONCLUSIONS

Completely resected localized BCs in pediatric patients have a favorable outcome also with lung tissue sparing surgery. Atypical BC with risk of metastatic spread and recurrence occurred more frequently compared to adults. Interdisciplinary management and collaborative efforts are needed to improve our understanding and the management of pediatric BC.

The Surgical Management of Lung Neuroendocrine Neoplasms

This review summarizes key recent developments relevant to the surgical management of lung neuroendocrine neoplasms (L-NENs), including typical and atypical carcinoids, large cell neuroendocrine carcinoma, and small cell lung carcinoma. This review includes recent insights into the classification, clinical presentation, diagnostic workup, treatment options, and follow-up. Highlighted topics include general principles of surgery in localized or locally advanced or metastatic L-NENs, lung-sparing surgery for small, peripheral typical carcinoids, adjuvant and systemic therapies for typical and atypical carcinoids, and surgery and adjuvant therapies for large cell neuroendocrine carcinoma and small cell lung carcinoma.

Current Management of Carcinoid Tumor

Bronchopulmonary carcinoid tumors are rare, well-differentiated neuroendocrine neoplasms. They can be categorized as typical or atypical lesions and are low-to-intermediate-grade, respectively. The cornerstone of therapy for carcinoid tumors is surgical resection and current consensus guidelines recommend anatomic resection for stage I to IIIA disease. The renewed interest in sublobar resections for the treatment of lung malignancies has sparked debate over the degree of resection necessary for these indolent lesions. Segmentectomy provides an oncologic resection while preserving as much lung parenchyma as possible, and is a reasonable approach to apply to small, undifferentiated, or typical carcinoid lesions.

Carcinoid tumors outside the abdomen

Neuroendocrine tumors (NETs) are epithelial malignancies that can arise from multiple tissues. Gastrointestinal (GI) NETs are the most common; in this review of extra-abdominal carcinoid tumors, we focus our discussion on bronchial and thymic carcinoid tumors. Bronchial carcinoid tumors comprise a quarter of all NETs and less than 2% of all lung cancers. Thymic carcinoid tumors are extremely rare, accounting for 5% of thymic tumors. Both bronchial and thymic carcinoid tumors are histologically classified as either typical or atypical based on their mitotic rate (less than 2 or 2-10 mitoses per 10 high-powered fields (HPF), respectively). Both bronchial and thymic carcinoids can present with symptoms of obstruction and potentially carcinoid syndrome. The gold standard of management of bronchial and thymic carcinoid tumors is surgical resection. For patients with advanced disease, first-line systemic therapy is generally somatostatin analog monotherapy with octreotide or lanreotide. In patients with refractory disease, therapy generally involves peptide receptor radioligand therapy, everolimus, or cytotoxic chemotherapy. There are ongoing, prospective trials comparing the mainstays of systemic therapy for these patients, as well as ongoing evaluations of immune checkpoint inhibitors and multi-kinase inhibitors. Prognosis for both bronchial and thymic carcinoid tumors depends on histologic grade, local versus invasive disease, and extent of metastases. Herein we provide a summary of the pathophysiologic and clinical background, the current state of the field in diagnosis and management, and note of key ongoing prospective trials for patients with bronchial and thymic carcinoid tumors.

Anatomic Pulmonary Resection is Associated With Improved Survival in Typical Carcinoid Lung Tumor Patients

BACKGROUND

The optimal extent of resection for a patient with a typical carcinoid tumor has been controversial. Studies suggest that wedge resection is an adequate oncologic operation for this tumor type.

MATERIALS AND METHODS

We analyzed the National Cancer Database to determine an optimal surgical resection for patients with a typical carcinoid tumor. We determined the number of patients who had typical carcinoid tumors. We then performed a survival analysis of the propensity-matched group of patients having a pathologic stage I typical carcinoid tumor who had undergone anatomic pulmonary resection (lobectomy and segmentectomy) or wedge resection.

RESULTS

A total of 10,265 patients met the inclusion and exclusion criteria: 8956 (87%) had a typical carcinoid tumor, while 1309 patients (13%) had an atypical carcinoid tumor. Among patients with typical carcinoid tumors, there were 7163 patients (80%) who underwent anatomic pulmonary resection (6755 patients with lobectomy, 94% and 408 patients with segmentectomy, 6%) and 1793 patients (20%) who underwent wedge resection. In this cohort, patients who had an anatomic resection had significantly improved 5-y survival compared to patients who had wedge resection (91% versus 84%, P < 0.001). In the propensity score-matched group of stage I typical carcinoid tumors (n = 1348), the patients who had an anatomic resection had significantly improved survival compared to patients who had wedge resections (89% versus 85%, P = 0.01) at 5 y.

CONCLUSIONS

The anatomic resection compared to wedge resection was associated with improved survival in patients with early-stage typical carcinoid lung cancer. Surgically fit patients should be considered for anatomic resection for typical carcinoid tumors.

Bibliometric Analysis of 50 Most Cited Articles Comparing Lobectomy with Sublobar Resection

BACKGROUND

 Recent years have seen an increase in the number of studies of the sublobar resection approach in non-small cell lung cancer (NSCLC) surgery. The purpose of this bibliometric analysis is to assess the significance and impact of articles comparing sublobar resection and lobectomy in NSCLC surgery.

MATERIAL AND METHODS

 The Web of Science database was searched to identify studies comparing sublobar resection and lobectomy in NSCLC surgery published between 2005 and 2020 (accessed: September 11, 2020). The 50 most cited articles were analyzed by years, countries, authors, authors' affiliations, journals, journals' addresses, and impact factors.

RESULTS

 The bibliometric analysis revealed that the most cited article had 443 citations, while the total number of citations of all articles was 2,820. The mean number of citations, in turn, was 56.4 ± 75.62 (1-443) times. The highest number of publications over the past 15 years was in 2016, with eight articles. The Annals of Thoracic Surgery (n = 10; 20%) had the highest number of publications on the list. The articles included in the present study were mostly (n = 35, 70%) published in U.S. journals. While multiple subject matters and analyses were presented by many studies, survival was the topic of greatest interest, with 37 (74%) studies.

CONCLUSION

 This study revealed that interest in studies comparing sublobar resection with lobectomy has increased in recent years. It also presents both quantitative and qualitative analyses of the most cited articles in the literature on this topic. Therefore, it can serve as a guide for researchers.

Surgical Principles in the Management of Lung Neuroendocrine Tumors: Open Questions and Controversial Technical Issues

OPINION STATEMENT

Primary neuroendocrine tumors (NETs) of the lung represent a heterogeneous group of malignancies arising from the endocrine cells, involving different entities, from well differentiated to highly undifferentiated neoplasms. Because of the predominance of poorly differentiated tumors, advanced disease is observed at diagnosis in more than one third of patients making chemo- or chemoradiotherapy the only possible treatment. Complete surgical resection, as defined as anatomical resection plus systematic lymphadenectomy, becomes a reliable curative option only for that little percentage of patients presenting with stage I (N0) high-grade NETs. On the other hand, complete surgical resection is considered the mainstay treatment for localized low- and intermediate-grade NETs. Therefore, in the era of the mini-invasive surgery, their indolent behavior has suggested that parenchyma-sparing resections could be as adequate as the anatomical ones in terms of oncological outcomes, leading to discuss about the correct extent of resection and about the role of lymphadenectomy when dealing with highly differentiated NETs.

Clinical-Pathologic Challenges in the Classification of Pulmonary Neuroendocrine Neoplasms and Targets on the Horizon for Future Clinical Practice

Diagnosing a pulmonary neuroendocrine neoplasm (NEN) may be difficult, challenging clinical decision making. In this review, the following key clinical and pathologic issues and informative molecular markers are being discussed: (1) What is the preferred outcome parameter for curatively resected low-grade NENs (carcinoid), for example, overall survival or recurrence-free interval? (2) Does the WHO classification combined with a Ki-67 proliferation index and molecular markers, such as OTP and CD44, offer improved prognostication in low-grade NENs? (3) What is the value of a typical versus atypical carcinoid diagnosis on a biopsy specimen in local and metastatic disease? Diagnosis is difficult in biopsy specimens and recent observations of an increased mitotic rate in metastatic carcinoid from typical to atypical and high-grade NEN can further complicate diagnosis. (4) What is the (ir)relevance of morphologically separating large cell neuroendocrine carcinoma (LCNEC) SCLC and the value of molecular markers (RB1 gene and pRb protein or transcription factors NEUROD1, ASCL1, POU2F3, or YAP1 [NAPY]) to predict systemic treatment outcome? (5) Are additional diagnostic criteria required to accurately separate LCNEC from NSCLC in biopsy specimens? Neuroendocrine morphology can be absent owing to limited sample size leading to missed LCNEC diagnoses. Evaluation of genomic studies on LCNEC and marker studies have identified that a combination of napsin A and neuroendocrine markers could be helpful. Hence, to improve clinical practice, we should consider to adjust our NEN classification incorporating prognostic and predictive markers applicable on biopsy specimens to inform a treatment outcome-driven classification.

Pulmonary carcinoid tumours: A multi-centre analysis of survival and predictors of outcome following sublobar, lobar, and extended pulmonary resections

BACKGROUND

Pulmonary carcinoids are rare neoplasms, accounting for approximately 1%-2% of all lung malignancies. A retrospective analysis was undertaken of all patients who underwent surgical resection of pulmonary carcinoid tumours across multiple institutions in Melbourne, Australia.

METHODS

From May 2000 through April 2020, 241 patients who underwent surgical resection of pulmonary carcinoid tumours were retrospectively reviewed. Patient demographics, pathologic data, and long-term outcomes were recorded.

RESULTS

Median age was 57.7 years and the majority of patients were female (58.9% vs. 41.1%). Typical carcinoid was present in 77.1%. Histological subtype was associated with several factors. Atypical carcinoid was more likely to have larger tumour size and nodal involvement. Overall survival for typical carcinoid at 5, 10, and 15 years was 98%, 95%, and 84%, and for atypical carcinoid was 88%, 82%, and 62%, respectively. Histological subtype and age were found to be independent predictors of overall survival, with worse outcomes for atypical and those above 60 years of age. Disease-free survival was related to sublobar resection (p < 0.001, sub-hazard ratio (SHR): 6.89), lymph node involvement (p = 0.022, SHR: 3.18), and atypical histology (p < 0.001, SHR: 9.89).

CONCLUSION

Excellent long-term outcomes can be achieved following surgical resection of pulmonary carcinoids. Atypical histology and lymph node involvement are significant prognostic factors, and sublobar resection should not be considered in patients with either of the above features. Typical carcinoid tumour without nodal involvement may be appropriate for sublobar resection. Typical and atypical carcinoid tumours should be considered distinct disease entities, and as such treated accordingly.

Wedge Resection Offers Similar Survival to Segmentectomy for Typical Carcinoid Tumors

Current guidelines recommend anatomic lung resection of typical bronchopulmonary carcinoids. Typical carcinoid tumors have excellent prognosis and sublobar resection has been associated with noninferior long-term survival. It's unclear whether wedge resection is acceptable for small typical carcinoid tumors. We hypothesize there is no difference in survival between wedge resection and segmentectomy for Stage I typical bronchopulmonary carcinoid tumors. Using the National Cancer Database from 2010 to 2016, we identified clinical T1N0M0 typical bronchopulmonary carcinoid tumors by wedge resection or segmentectomy. Short-term outcomes included length of stay, lymph nodes evaluated, pathologic node status, positive margin status, and 90-day mortality. Primary outcome was overall survival and estimated using Kaplan-Meier survival analysis. 821 patients were identified: 677 receiving wedge resection, 144 receiving segmentectomy. Segmentectomy was more commonly performed in an academic setting (70.0% vs 57.3%, P = 0.005). The mean tumor size for segmentectomy was 1.7 cm versus 1.4 cm for wedge resection (P < 0.001). There was no difference in LOS, positive margin status, and 90-day mortality between groups. There were significantly more lymph nodes evaluated in segmentectomy patients (median 4 vs 0, P < 0.001), but there was no difference in positive lymph node status (5.3% vs 2.6%, P = 0.165). The OS was similar between wedge and segmental resection (P = 0.613): 3-year survival (93.5% vs 92.8%) and 5-year survival (83.8% vs 84.9%). Wedge resection and segmentectomy have similar survival for Stage I typical bronchopulmonary carcinoids in a large national database. This analysis suggests nonanatomic, parenchymal-sparing resection should be considered an appropriate alternative for Stage I typical bronchopulmonary carcinoids.

Preoperative Biopsy Diagnosis in Pulmonary Carcinoids, a Shot in the Dark

INTRODUCTION

The preferred treatment for pulmonary carcinoids (PCs) is lobectomy, and parenchyma-sparing approaches might be considered for typical carcinoids (TCs). Treatment decisions are based on a preoperative biopsy diagnosis. Following the WHO criteria (2015), definitive diagnosis is only feasible postoperatively, thereby hampering preoperative treatment decisions. Here, we determined whether the final carcinoid classification on a resection specimen can be predicted by a preoperative biopsy.

METHODS

We searched all stage I to III patients with a final carcinoid diagnosis who underwent a curative resection and of whom both a preoperative biopsy and paired resection specimen were available (2003-2012) using the Dutch Pathology Registry (PALGA) and the Netherlands Cancer Registry (IKNL). Pathology report conclusions of the biopsy-resection specimen were compared.

RESULTS

Paired biopsy-resection specimens in combination with clinical data were available from 330 patients. 57% (189 of 330) of the patients exhibited discordance between the preoperative biopsy and paired resection diagnosis, including 36% (44 of 121) preoperatively diagnosed TC, 40% (six of 15) atypical carcinoid (AC), and 65% (103 of 158) not-otherwise-specified (NOS) carcinoids. A quarter of preoperatively diagnosed TC and NOS was reclassified as AC on the resection specimen. Preoperatively diagnosed ACs exhibited the highest relapse rates (40%, 6 of 15). Preoperatively diagnosed TC and NOS patients who were reclassified as ACs exhibited higher relapse rates as compared to nonreclassified TCs and NOS (3% versus 1%, and 16% versus 6%).

CONCLUSIONS

We provide evidence that carcinoid classification on preoperative biopsies is imprecise, as is also stated by the current WHO classification. We advise clinicians to interpret the preoperative biopsy diagnosis with caution in deciding the extent of surgery (e.g., parenchyma-sparing versus non-parenchyma-sparing).

Neuroendocrine syndrome in bronchial carcinoid tumors

Pulmonary carcinoid tumors represent bronchopulmonary neuroendocrine neoplasms which might synthetize serotonin, histamine, bombesin or other types of hormones responsible for the development of a broad spectrum of signs and symptoms, known as carcinoid syndrome. Data of 98 patients submitted to surgery for bronchial carcinoid tumors in the Thoracic Surgery Clinic of the 'Marius Nasta' Institute of Pneumophtisiology between 2014 and 2018 were retrospectively reviewed. All patients were submitted to paraclinical tests, imagistic studies (computed tomography or magnetic resonance imaging), bronchoscopy and biopsy in order to have a positive diagnostic of pulmonary carcinoid. The most common clinical symptoms at the time of presentation were: Persistent cough followed by dyspnea and recurrent pulmonary infections. The main neuroendocrine syndromes found were Cushing and Carcinoid Syndrome. All patients were submitted to surgery with curative intent consisting of wedge resection (in 4 cases, 4.08%), lobectomy (in 79 cases, 80.61%), bilobectomy (in 5 cases, 5.1%) and pneumonectomy respectively (in 10 cases, 10.2%). In all cases neuroendocrine specific symptoms disappeared once the carcinoid tumor was removed. In conclusion, bronchial carcinoid tumors have a positive outcome in most cases. Specific neuroendocrine markers as well as neuroendocrine syndrome disappears once the tumor is removed.

The Effect of Tumor Size and Histologic Findings on Outcomes After Segmentectomy vs Lobectomy for Clinically Node-Negative Non-Small Cell Lung Cancer

BACKGROUND

The interaction between tumor size and the comparative prognosis of lobar and sublobar resection has been defined poorly.

RESEARCH QUESTION

The purpose of this study was to characterize the relationship between tumor size and the receipt of segmentectomy or lobectomy in association with overall survival in patients with clinically node-negative non-small cell lung cancer (NSCLC).

STUDY DESIGN AND METHODS

The 2004-2015 National Cancer Database (NCDB) was queried for patients with cT1-3N0M0 NSCLC who underwent segmentectomy or lobectomy without neoadjuvant therapy or missing survival data. The primary outcome was overall survival, which was evaluated using multivariate Cox proportional hazards including an interaction term between tumor size and type of surgery.

RESULTS

A total of 143,040 patients were included: 135,446 (95%) underwent lobectomy and 7594 (5%) underwent segmentectomy. In multivariate Cox regression, a significant three-way interaction was found among tumor size, histologic results, and type of surgery (P < .001). When patients were stratified by histologic results, lobectomy was associated with significantly improved survival compared with segmentectomy beyond a tumor size of approximately 10 mm for adenocarcinoma and 15 mm for squamous cell carcinoma that was recapitulated in subgroup analyses. No interaction between tumor size and type of surgery was found for patients with neuroendocrine tumors.

INTERPRETATION

In this NCDB study of patients with node-negative NSCLC, we found different tumor size thresholds, based on histologic results, that identified populations of patients who least and most benefitted from lobectomy compared with segmentectomy.