Prognosis of resected well-differentiated neuroendocrine carcinoma of the lung

Management of non-hepatic distant metastases in neuroendocrine neoplasms

Neuroendocrine neoplasms represent an uncommon disease with an increasing incidence. Thanks to improvements in diagnostic and therapeutic methods, metastases previously considered uncommon, such as bone metastases, or even very rare, such as brain, orbital and cardiac metastases, are more frequently found in daily practice. Due to the great heterogeneity of these neoplasms, there is a lack of high-quality evidence on the management of patients with these types of metastases. The aim of this review is to provide the current state of the art, reviewing neuroendocrine neoplasm specific studies and useful information from other tumor types and to propose a treatment recommendation with algorithms to consider in daily clinical practice.

A single-institution retrospective analysis of metachronous and synchronous metastatic bronchial neuroendocrine tumors

Background

Broncho-pulmonary neuroendocrine tumors (bpNETs) are rare malignancies and there is no consensus on therapeutical management of metastatic disease and follow-up after radical resection.

Methods

Clinical records of patients with a cytological or histological diagnosis of bpNETs and distant metastases (metachronous or synchronous), evaluated at the European Institute of Oncology between 1997 and 2014, were retrospectively analyzed. Data on patient demographics, pathology, imaging exams, surgical and non-surgical treatments were collected. P value descriptive data, uni- and multi-variate survival analysis were generated for all variables.

Results

With a median follow-up of 53 [9-215] months, 61 patients with metachronous and 47 with synchronous metastases were analysed. The most common tool of first recurrence detection was computed tomography. Liver (67%), lymph node (25%), bone (22%) and lung (16%) were the most common sites of relapse. Median time to recurrence was 5 years. Median overall survival (OS) was 72 months for the whole population, with no significant difference between patients with synchronous and metachronous metastases. Age, bone metastases, liver metastases and Ki-67 as a continuous variable all significantly correlated with prognosis at the multivariate analysis.

Conclusions

This is one of the largest, single-centre, series of metastatic bpNETs. Among patients with metachronous metastases the pattern of recurrences was heterogeneous as were the follow-up exams used to detect them. The results of our analysis may represent solid bases for designing prospective clinical trials in homogeneous settings of bpNETs.

[Multidetector computed tomography assessment of the degree of differentiation of bronchial carcinoid tumors]

OBJECTIVE

To define the CT findings for bronchial carcinoid tumors and to determine whether these findings enable these tumors to be classified as typical or atypical.

MATERIAL AND METHODS

We reviewed the chest CT studies performed between 1 January 2001 and 31 December 2009 in patients at our hospital diagnosed with bronchial carcinoid tumors. The sample consisted of 52 patients (23 women and 29 men) with a mean age of 47 years (range 11-77 years). The 52 cases were classified as typical or atypical on the basis of the following radiological findings: size, location, focality, type of growth, calcifications, signs secondary to bronchial obstruction, and the presence of significant lymph node enlargement or metastases. These findings were then compared with the histological findings.

RESULTS

Typical carcinoid tumors were the most prevalent (46 cases). The variables associated with atypical tumors were: male sex, advanced age at onset, and size >3cm. The accuracy of CT in classifying atypical tumors correctly increased with the number of variables indicative of atypical carcinoid tumors. A negative result for atypical nature made it possible to rule out an atypical carcinoid tumor in 95% of the cases.

CONCLUSION

CT is useful for defining and characterizing carcinoid tumors into typical or atypical, although a precise formula for differentiating between the two types remains to be defined.

Well-Differentiated Neuroendocrine Carcinomas: The Spectrum of Histologic Subtypes and Various Clinical Behaviors

The term "well-differentiated neuroendocrine carcinoma" was coined to describe a variety of demonstrably neuroendocrine tumors which were more aggressive (both with respect to their histologic appearance and their clinical course) than (typical) bronchial carcinoids but were also clearly distinguishable from small cell neuroendocrine carcinomas. This umbrella term encompasses a variety of tumors previously described by a variety of terms including "atypical" carcinoids, "malignant tumorlets," peripheral stage I small-cell carcinoma, as well as neoplasms described simply as "undifferentiated carcinoma" (prior to the recognition of their neuroendocrine properties). As such, this term is a broad term and is not simply synonymous with "atypical carcinoid." Over time, at least 3 subtypes have been identified based upon their histologic appearance and mitotic index, with correspondingly aggressive clinical courses.

Lack of telomerase activity in lung carcinoids is dependent on human telomerase reverse transcriptase transcription and alternative splicing and is associated with long telomeres

PURPOSE

Preliminary evidence indicates that telomerase activity is significantly less expressed in typical carcinoids than in large cell neuroendocrine carcinomas or in small cell lung cancers. Knowledge of the mechanisms by which telomerase is differentially regulated in neuroendocrine lung tumors is important for a better understanding of the pathogenesis of these malignancies.

EXPERIMENTAL DESIGN

We investigated telomerase activity in 86 neuroendocrine lung tumors and correlated the enzyme activity with the expression of the enzyme subunits [human RNA component (hTR), human telomerase reverse transcriptase (hTERT), and alternatively spliced hTERT variants], with the telomere-associated protein human protection of telomere-1, and with the telomere length pattern.

RESULTS

A significantly (P = 0.0001) lower frequency of telomerase-positive cases was found in typical carcinoids (14%) than in large cell neuroendocrine carcinomas (87%) and small cell lung cancers (92%). hTR was constitutively expressed in all carcinoids. Telomerase-negative carcinoids were characterized by the absence of any hTERT transcript, only displayed the beta(-) alternatively spliced variant, or concomitantly expressed the alpha(+)beta(+) full-length message with different combinations of alternatively spliced variants. However, in these tumors, a more abundant level of alternatively spliced transcripts than that of the alpha(+)beta(+) full-length transcript was generally found. No significant difference was observed in human protection of telomere-1 expression between telomerase-negative and telomerase-positive carcinoids. Telomeres were significantly (P < 0.05) longer in telomerase-negative carcinoids than in telomerase-positive carcinoids (median value, 9.15 versus 4.47 kb). However, alternative lengthening of telomeres, as shown by associated promyelocytic leukemia bodies, was not observed in these tumors.

CONCLUSIONS

Our results indicate that telomerase is repressed in most lung carcinoids and that hTERT transcription and alternative splicing play a role in such a negative regulation. Moreover, the absence of any telomerase maintenance mechanism may contribute to the favorable prognosis of this malignancy.

Transthoracic needle biopsy in the diagnosis of large-cell neuroendocrine carcinoma of the lung

To determine the effect of cytological diagnosis, fine-needle aspiration and brush cytology on lung tumors and core-needle biopsy, we retrospectively reviewed 11 cases of large-cell neuroendocrine carcinoma (LCNEC) found in our archives between the years 1997 and 2004. The preoperative cytological diagnosis of LCNEC is challenging because of the broad histologic similarity to other neuroendocrine tumors of the lung. The original cytologic diagnosis was LCNEC in nine of the cases while the remaining two were misdiagnosed as small-cell lung carcinoma. Smears were composed of clusters of intermediate-size cells with amphophylic cytoplasm, some with large nuclei and prominent nucleoli. In two of the cases there was discordance between the cytological findings and the immunohistochemical results. The cytological findings were correlated with histopathological observations.

Differential expression of telomerase activity in neuroendocrine lung tumours: correlation with gene product immunophenotyping

Telomerase activity was examined by the telomeric repeat amplification protocol (TRAP) assay in 38 neuroendocrine (NE) lung tumours. A significantly (p = 0.001) different frequency of telomerase positivity was observed among different histological tumour types. Specifically, a positive TRAP signal was observed in 14 of 15 (93%) small cell lung cancers (SCLCs), 7 of 8 (87%) large-cell NE carcinomas (LCNECs), and only 1 of 15 (7%) typical carcinoid tumours. When telomerase activity was correlated with the gene product-based immunophenotypic profile of individual tumours, it was found that the absence of telomerase activity was associated with a lack of bcl-2, p53, and c-kit expression, and characterized by a low proliferation index consistent with the absence of cdk-4 expression and the presence of the cdk inhibitor Rb. Such a phenotype was appreciable in most of the carcinoid tumours. Conversely, telomerase-positive tumours generally showed an immunophenotype consistent with gene product alterations (including high expression of bcl-2, p53, and c-kit, and loss of Rb) and were characterized by a high proliferation index. These telomerase data support the previously reported evidence for two genetically unrelated groups of NE lung tumours (SCLC, and to some extent LCNEC, versus carcinoid tumours) that have distinct phenotypic profiles.

Neuroendocrine tumors of the bronchopulmonary tract: a reappraisal of their classification after 20 years

This article is an overview of the classification of pulmonary neuroendocrine neoplasms, their presentation, their pathologic appearance, and their clinical management. In addition, the original classification, based on histologic features, is reassessed in the light of newer areas in study, including neurosecretory products, neuroendocrine markers, ultrastructural studies, ploidy analysis, cell adhesion markers, apoptosis, oncogene mutation analysis, and genetic alterations. The histologic classification proposed in 1983 remains the single most valuable factor in establishing the diagnosis and, together with the TNM status, the prognosis of this group of interesting neoplasms.

Pulmonary neuroendocrine carcinomas. A review of 234 cases and a statistical analysis of 50 cases treated at one institution using a simple clinicopathologic classification

CONTEXT

Primary pulmonary neuroendocrine tumors are traditionally classified into 3 major types: typical carcinoid (TC), atypical carcinoid (AC), and large cell neuroendocrine carcinoma (LC) or small cell neuroendocrine carcinoma (SC). Confusion arises frequently regarding the malignant nature of TC and the morphologic differentiation between AC and LC or SC.

OBJECTIVE

To provide clinicopathologic evidence to streamline and clarify the histomorphologic criteria for this group of tumors, emphasizing the prognostic implications.

PATIENTS

To minimize variability in diagnostic criteria and treatment plans, we analyzed a group of patients whose diagnosis and treatment occurred at a single institution. We reviewed 234 cases of primary pulmonary neuroendocrine tumors and thoroughly studied 50 cases of resected tumors from 1986 to 1995.

RESULTS

On the basis of morphologic characteristics and biologic behaviors of the tumors, we agree with many previous investigators that these tumors are all malignant and potentially aggressive. Based on our accumulated data, we have modified Gould criteria and reclassified these tumors into 5 types: (1) well-differentiated neuroendocrine carcinoma (otherwise called TC) (14 cases, with less than 1 mitosis per 10 high-power fields [HPF] with or without minimal necrosis); (2) moderately differentiated neuroendocrine carcinoma (otherwise called low-grade AC) (6 cases, with less than 10 mitoses per 10 HPF and necrosis evident at high magnification); (3) poorly differentiated neuroendocrine carcinoma (otherwise called high-grade AC) (10 cases, with more than 10 mitoses per 10 HPF and necrosis evident at low-power magnification); (4) undifferentiated LC (5 cases, with more than 30 mitoses per 10 HPF and marked necrosis); and (5) undifferentiated SC (15 cases, with more than 30 mitoses per 10 HPF and marked necrosis). The 5-year survival rates were 93%, 83%, 70%, 60%, and 40% for well, moderately, and poorly differentiated, and undifferentiated large cell and small cell neuroendocrine carcinomas, respectively. We found nodal metastasis in 28% of TC in this retrospective review, a figure higher than previously recorded.

CONCLUSION

Using a grading system and terms comparable to those used for many years and used for neuroendocrine tumors elsewhere in the body, we found that classification of pulmonary neuroendocrine carcinomas as well, moderately, poorly differentiated, or undifferentiated provides prognostic information and avoids misleading terms and concepts. This facilitates communication between pathologists and clinicians and thereby improves diagnosis and management of the patient.

Unusual primary lung neoplasms

Bronchial carcinoids and hamartomas are, respectively, the most common malignant and benign unusual primary lung neoplasms. These tumors are often asymptomatic but can cause central airway obstruction. Helical computed tomographic and radionuclide scintigraphic advances in their detection and evolution, together with newer interventional bronchoscopy techniques such as neodymium:yttrium-aluminum-garnet laser phototherapy and cryotherapy, represent important improvements in the diagnosis and management of patients with such tumors.

Prognostic factors in neuroendocrine lung tumors: a Spanish Multicenter Study. Spanish Multicenter Study of Neuroendocrine Tumors of the Lung of the Spanish Society of Pneumonology and Thoracic Surgery (EMETNE-SEPAR)

BACKGROUND

This study examines the experience of the Spanish Multicenter Study of Neuroendocrine Tumors of the Lung through the clinical data and behavior of patients treated for this pathologic process.

METHODS

From 1980 to 1997, 361 cases of neuroendocrine carcinomas (NEC) were treated surgically. Patients were enrolled in a protocol using the pathologic and follow-up reports. According to Dreslers' criteria, the cases were segregated into grade 1 (typical carcinoid), grade 2 (atypical carcinoid), grade 3 large cell type, and grade 3 small cell type. Several variables were reviewed in all patients. Statistical analysis was performed to determine whether clinical characteristics and differentiation were associated with significant differences in the prognosis.

RESULTS

A total of 261 cases of NEC were identified with grade 1, 43 with grade 2, and with grade 3: 22 of large and 35 of small cells. Five-year survival for different grades was as follows: grade 1, 96%; 2, 72%; 3 large cell type, 21%; and 3 small cell type, 14%. When a comparative analysis between typical and atypical carcinoids was performed a significant difference for mean age, tumor size, nodal metastases, and recurrence was observed. However, female sex, nodal metastases, and recurrence rate differed between atypical carcinoids and grade 3 NEC of large cells. A difference in recurrence rate was found between patients with both types of grade 3 NEC.

CONCLUSIONS

The progressive deterioration of tumor organization highlights that neuroendocrine tumors constitute a continuous spectrum. A careful observation of pathologic findings is necessary to individualize their prognostic factors.

Molecular markers help characterize neuroendocrine lung tumors

BACKGROUND

The terms large cell and mixed small-large cell neuroendocrine carcinoma (LCNC, MNC) have been proposed to describe distinct types of high-grade neuroendocrine lung tumors. However, cytologic appearance and neuroendocrine immunohistochemical stains cannot uniformly distinguish these from other neuroendocrine tumors, such as typical and atypical carcinoids or small cell carcinoma, or nonendocrine lung cancers such as large cell undifferentiated carcinoma. This study sought to determine the patterns of expression in LCNC and MNC of several molecular markers often abnormally expressed in lung cancers.

METHODS

Primary lung tumors with neuroendocrine features operated on between 1984 and 1994 were reviewed and classified as typical carcinoid (TC), atypical carcinoid (AC), LCNC, MNC, and small cell lung cancer (SCLC) based on mitotic rate, extent of necrosis, and cytoarchitectural features. Immunohistochemistry was performed using antibodies MIB-1 for Ki67, pAb1801 for p53, OP-66 for Rb, 31G7 for EGFR. Staining was scored as 0 to 4+ (0 = less than 5%, 1+ = 5% to 20%, 2+ = 20% to 50%, 3+ = 50% to 80%, 4+ = more than 80%) for p53, Ki67, and EGFR; and negative, focal, or positive for Rb. Overall survival was calculated by the Kaplan-Meier method and prognostic factors compared by log rank test.

RESULTS

Ninety-two tumors were examined: 25 TC, 7 AC, 24 LCNC, 18 MNC, 18 SCLC. The LCNC and MNC presented more frequently as stage II or III tumors (n = 28, 66%) than TC and AC (n = 5, 15%). Median survival for LCNC and MNC was 18.7 months, for SCLC 14.3 months, and has not been reached for TC and AC tumors. TC and AC tumors were uniformly characterized by low proliferative rate, absent p53, and normal Rb staining. LCNC, MNC, and SCLC showed a high proliferative rate, abnormal p53, and absent Rb staining. Overexpression of EGFR was frequent in all five tumor types.

CONCLUSIONS

(1) Ki67, p53, and Rb help distinguish LCNC and MNC from TC and AC. (2) Small numbers of patients preclude comparison of survival rates, but LCNC/MNC have a median survival similar to comparable early stage SCLC, and clearly worse than TC/AC. These results justify a sharp separation of high-grade neuroendocrine tumors from carcinoids, and suggest a close relationship between LCNC, MNC, and SCLC.

Surgery for cure followed by chemotherapy in small cell carcinoma of the lung. For the ISC-Lung Cancer Study Group

The Lung Cancer Study Group of the International Society of Chemotherapy (ISC-LCSG) organized multinational, cooperative, prospective and randomized trials for the cure of patients with small cell lung cancer at early stages (T1,2N0M0). Surgery for cure was used first, followed by postoperative chemotherapy, and thereafter by prophylactic cranial irradiation. Eight cycles of standard chemotherapy (CAV-cyclophosphamide-doxorubicin-vincristine) or 6 intermittent cycles of alternating chemotherapy, using 3 different drug combinations, were administered 1-2 weeks postoperatively for 6 months after randomization. A total of 183 evaluable patients received surgery for cure at 23 cooperating hospitals. The preliminary evaluation of ISC-studies I and II per May 1993 resulted in the 30-month total survival of 63% from 68 patients after complete resection at TN0M0R0-stages and 37% from 27 patients after such resections at TN2M0R0-stages. Their incidence of local recurrence as first relapse was quite similar (11/47:8/39). The related 4-year recurrence-free survival (57%, 37%), indicating a plateau-like curve of long-term survivors. These promising results have to be confirmed by larger studies. We conclude that the indication for surgery as the first treatment step for SCLC should be the same as for the other non-small subtypes of lung cancers.