Tumorlets, multicentric carcinoids, lymph-nodal metastases, and long-term behavior in bronchial carcinoids.

BACKGROUND: The clinical significance of lymph-node metastases, multicentric forms, and tumorlets in bronchial carcinoids is still a matter of debate. Aim of this study was to analyze their prevalence and clinical significance in a series of 123 bronchial carcinoids. PATIENTS AND METHODS: Nodal dissection and serial sections of resected lung parenchima for research of multicentric forms and tumorlets were performed in most patients. Survival curve was produced using the Kaplan-Meyer method and multivariate analysis by the Cox proportional hazard model. RESULTS: Lymph-node involvement was present in 14% of typical (14 of 100) and 13.04% of atypical carcinoids (3 of 23). Multicentric forms (syncronous carcinoids or tumorlets) were found in 11.3% of the total with a negative impact on survival (p = 0.021). Multiple tumorlets were found in 7.3% of all cases at the standard pathologic examination, but whenever accurate palpation and serial sections of the surgical specimen were performed, the percentage reached 24% of the cases. Overall survival was 98.2%, 95.8%, and 83.9% for typical and 71.6%, 57.3%, and 24% for atypical carcinoid respectively at 5, 10, and 15 years. Time from surgery was significantly directly correlated with recurrences (p < 0.0001) and disease related death (p = 0.0002). CONCLUSIONS: A high prevalence of tumorlets, multiple carcinoids, and lymph-nodal involvement was found in our series. On the basis of these observations bronchial carcinoids always require major surgical procedures with systematic nodal dissection, and a careful search for multifocal lesions should always be performed. Follow-up should always be accurate and protracted, due to the frequency of very long-term relapses (often more than 10 years after surgery).

Surgical treatment of neuroendocrine tumors of the lung.

OBJECTIVE: This report reviews the pattern of neuroendocrine (NE) differentiation, lymph-node involvement, extension of surgery, and survival in 125 NE lung tumor patients. METHODS: Standard diagnostic workup included CT scan, bronchoscopy, bronchial biopsy or Fine Needle Aspiration Biopsy, (111)In-pentetreotide scan (OctreoScan) and mediastinoscopy in selected patients. NE differentiation was assessed based on the morphology and immunohistochemical reactivity for pan-neuroendocrine markers NSE, CGA, and Synaptophysin. For small cell carcinoma (SCC), only clinical stage I and II patients underwent surgery. Several different surgical procedures were utilized, from limited resections to lobectomy, pneumonectomy, and bronchoplastic procedures. Survival was assessed using Kaplan-Meyer method at 5 years. RESULTS: There were 79 typical carcinoid (TC), eight atypical carcinoid (AC), 18 large cell carcinoma (LCC) and 20 SCC patients. Mean age at diagnosis was 54.6+/-15.2 (ranges from 16 to 77 years) for TC, 68.5+/-9.1 (range 53-81) for AC, 68.7+/-4.6 (range 58-77) for LCC, 64.6+/-7.9 (range 48-82) for SCC. Male/female ratio was 1/1 for TC and AC, 2.6/1 for LCC and 9/1 for SCC. Lymph-node involvement was present in 14% of TC, 0% of AC, 31.5% of LCC, and 45% of SCC. Cancer specific survival was 96% for TC, 87.5% for AC, 37.5% for LCC, and 30% for SCC at 5 years from surgery. Presenting symptoms were invariably of respiratory-related. None had the carcinoid syndrome. History of tobacco abuse ranged from 46% for TC to 100% in SCC. Survival ranged from a minimum of 1 month for SCC to a maximum of 168 months with no evidence of disease for TC. Synchronous multicentric forms were found in 14% of TC. Twenty-one percent (4/19) of the patients with SCC treated by induction therapy and surgery, and in few cases by surgery and adjuvant chemotherapy are alive without the evidence of the disease for 5 years. CONCLUSIONS: Due to the high percentage of lymph-node involvement and multicentric forms found in our series lobectomy with radical lymph-node dissection appears, in our opinion, the most appropriate surgical treatment in well-differentiated forms, while more limited resection appears sub-optimal. Also, due to the finding of recurrences many years after surgery, the follow-up must be accurate and protracted in this subgroup. Only Small Cell Lung Carcinoma patients in clinical stage I and II underwent surgery with good long-term results.

BRAF(V599E) mutation is the leading genetic event in adult sporadic papillary thyroid carcinomas.

Activating mutations of BRAF have been identified in a variety of human cancers, most notably melanomas and papillary thyroid carcinomas (PTCs). The aim of the present study was to disclose the role of BRAF mutations in thyroid carcinoma development. Seventy-two thyroid tumors, including 60 PTCs, six follicular adenomas, five follicular carcinomas, and one anaplastic carcinoma, were studied. BRAF mutation screening focused on exon 15 and exon 11 of the gene by single-stranded conformational polymorphism and sequence analysis. Search of RET/PTC expression was conducted with the RT-PCR technique. The molecular genetic study of the BRAF gene showed the presence of a missense thymine to adenine transversion at nucleotide 1796, resulting in the V599E substitution, in 24 of 60 PTCs (40%), none of six follicular adenomas, and none of five follicular carcinomas or one anaplastic carcinoma. Moreover, nine of 60 PTCs (15%) presented RET/PTC expression. A genetico-clinical association analysis showed a statistically significant correlation between BRAF mutation and development of PTCs of the classic papillary histotype (P = 0.038). On the contrary, no link could be detected between expression of BRAF(V599E) and age at diagnosis, gender, dimension, and local invasiveness of the primary cancer, presence of lymph node metastases, tumor stage, and multifocality of the disease. These data clearly confirm that BRAF(V599E) is the more common genetic alteration found to date in adult sporadic PTCs, that it is unique for this thyroid cancer histotype, and that it might drive the development of PTCs of the classic papillary subtype.

Ret/PTC activation does not influence clinical and pathological features of adult papillary thyroid carcinomas.

OBJECTIVE: RET proto-oncogene rearrangements (ret/PTCs) represent the most common genetic alterations found in papillary thyroid carcinomas (PTCs). Correlation of ret/PTC expression with clinical outcome is controversial. The aim of the present study was to analyze the frequency of RET rearrangements in adult PTCs, and to investigate if ret/PTCs influence biological behavior and clinical features of the cancers. DESIGN: Ret/PTC rearrangements were looked for in tIssue samples of 48 PTCs collected at our institution. Data about clinical and pathological features of the tumors were also reviewed. Three separate association analyses were carried out on the cohort evaluating the effects of, respectively, ret/PTC positivity, preferential RET tyrosine kinase domain (RET-TK) expression, and ret/PTC plus RET-TK positivity, on age, sex, tumor size, staging, number of neoplastic foci, and histological subtype. METHODS: The genetic study was conducted with the RT-PCR-Southern blot technique. Standard Student's t-test and Fisher exact test were applied for the association analyses. RESULTS: The molecular genetic study demonstrated the positivity of ret/PTC1 and ret/PTC3 in 13 of 48 tumors (27.1%), and an exclusive or preferential RET-TK expression in 17 cases (35.4%). None of the three genetico-clinical analyses showed any significant association between ret/PTC expression and the clinical and pathological features of the cancers. CONCLUSIONS: These data indicate that RET rearrangements may not play any distinctive role in driving histotype development and cancer progression in these neoplasms. Moreover, they weaken the possibility of using ret/PTC as a prognostic marker for papillary thyroid carcinomas.

[Prevalence of the neuroendocrine phenotype in thymus neoplasms]. / Prevalenza del fenotipo neuroendocrino nelle neoplasie del timo.

To determine the prevalence of neuroendocrine differentiation in human thymic neoplasms, which are unusual tumours that may range from well-differentiated to overtly malignant, poorly differentiated lesions, an immunohistochemical study was conducted in 23 thymic neoplasms re-classified on the basis of the new 1999 WHO classification. Immunohistochemical evidence of neuroendocrine differentiation in the form of reactivity to the markers synaptophysin, neuron-specific enolase and chromogranin A was found in 6 of 23 tissues (26%). Two of 3 patients with thymic carcinoids (or well-differentiated thymic neuroendocrine carcinoma) were affected by multiple endocrine neoplasia type 1 (MEN-1). Myasthenia gravis was present in 2/6 patients with neuroendocrine differentiation. This study demonstrates the high prevalence of neuroendocrine markers in human thymic neoplasms. Whether and in what percentage of cases immunohistochemical reactivity may be correlated with clinical behaviour and outcome remains a controversial issue. Finally, the association between thymic carcinoids and MEN-1 is a strong indication for clinical and possibly genetic screening of all patients presenting this feature, just as all MEN-1 patients have to undergo thoracic imaging and prophylactic thymectomy in selected cases.