Patients with locally advanced or metastatic PEC who are treated with FAS may have a reasonable RR, and responders may experience longer PFS and OS. The volume of metastases in the liver is the most important predictor of outcome.
Hereditary medullary thyroid carcinoma (MTC) is caused by autosomal dominant gain-of-function mutations in the RET proto-oncogene. Associations between specific RET mutations (genotype) and the aggressiveness of MTC and presence or absence of other endocrine neoplasms (phenotype) are well documented. Mutations in six exons (10, 11, 13, 14, 15, and 16) located in either cysteine-rich or tyrosine kinase domains cause one of three distinctive clinical subtypes: familial MTC, multiple endocrine neoplasia (MEN) type 2A (including variants with Hirschsprung's disease and cutaneous lichen amyloidosis), and MEN 2B. Hallmarks of MEN 2A include MTC, pheochromocytoma, and hyperparathyroidism. MEN 2B is associated with an earlier onset of MTC and pheochromocytoma, the absence of hyperparathyroidism, and the presence of striking physical stigmata (e.g., coarse facies, ganglioneuromatosis, and marfanoid habitus). Familial MTC is not associated with other endocrine neoplasms; however, the accurate distinction between familial MTC and MEN 2A may be difficult in kindreds with small size, incomplete histories, or a predominance of young individuals who may not have yet fully manifested the syndrome. Genetic testing detects greater than 95% of mutation carriers and is considered the standard of care for all first-degree relatives of patients with newly diagnosed MTC. Recommendations on the timing of prophylactic thyroidectomy and the extent of surgery are based upon a model that utilizes genotype-phenotype correlations to stratify mutations into three risk levels. 531
Introduction: Pancreatic endocrine tumors (PETs) occur in at least 50% of patients with multiple endocrine neoplasia type 1 (MEN1) and are the leading cause of disease-specific mortality. However, the timing and extent of surgery for MEN1-related PETs is controversial owing to the indolent tumor growth seen in most patients and the desire to avoid complications associated with insulin dependence. To help resolve this controversy, we retrospectively analyzed the clinical characteristics, surgical treatment, and clinical outcome of patients with MEN1-related PETs. Methods: All patients had histologic or radiographic confirmation of a PET in the setting of MEN1. Disease progression was defined radiographically as the development of new pancreatic tumors or distant metastases. Progression-free survival (PFS) and overall survival (OS) were used as the endpoints of this analysis. Results: We identified 98 patients with MEN1, 55 (56%) of whom had PETs, including 27 women and 28 men with a median age of 37 years (range 8-69 years) at the time of diagnosis. Functioning PETs were present in 35 (64%) of 55 patients, and nonfunctioning tumors were present in 20 (36%). Pancreatic surgery was performed in 38 (69%) of the 55 patients; and the first operation included enucleation (n = 4), total pancreatectomy (n = 3), Whipple procedure (n = 4), and distal pancreatectomy (n = 27). The median size of the resected tumors was 2.8 cm (range 0.6-11.0 cm). Recurrent disease developed in the residual pancreas in 7 (20%) of 35 at-risk patients a median of 7.8 years after the first operation, and distant metastases occurred in 5 (14 %) of 36 surgically treated patients without distant metastasis (2 patients had distant metastases when surgery on the primary tumor was performed) at a median of 2.7 years following surgery. At last follow-up, 16 (29%) of 55 patients with PETs had died, 12 (22%) were alive with disease, 26 (47%) were alive without evidence of disease, and 1 (2%) was lost to follow-up. The median OS was 19.5 years (range 13-26 years) and was significantly longer for patients who had functioning PETs versus those with nonfunctioning tumors (P = 0.0007), for patients who underwent surgical resection of their PETs versus those who did not (P = 0.0043), and for patients with localized versus metastatic PETs at the time of diagnosis (P < 0.0001). Multivariate analysis revealed that
Hypothesis: Multiple endocrine neoplasia type 1 (MEN 1) syndrome is an autosomal dominant disorder caused by germline mutations in the MEN1 gene and characterized by multiple endocrine tumors, most notably in the parathyroid glands, pituitary, and pancreas. The syndrome demonstrates variable expressivity and considerable genetic heterogeneity. Patient data were examined for possible associations between genotype and phenotype. Design: We reviewed recorded medical data from 1975 to 2001 on patients with MEN 1 and compared specific types and locations of MEN1 gene mutations with manifestations of the syndrome. Patients and Results: We identified 109 affected patients from 24 MEN 1 kindreds. The phenotypic expression of MEN 1 in affected individuals included hyper-parathyroidism in 74%, pancreatic endocrine tumors in 51%, and pituitary tumors in 35%. Twelve of 14 insulinomas occurred in patients with pituitary tumors. Mutation analysis was completed in 14 of 24 kindreds (80 of the 109 patients). Mutations were most common in exons 2 (31%), 9 (15%), and 10 (23%). All 21 patients with frameshift mutations (and known pancreatic endocrine tumor status) had such tumors. Pituitary tumors were associated with frameshift mutations in exon 2. Conclusions: The type and location of MEN1 mutations may be associated with the phenotypic expression of specific tumors. Such information may assist in the genetic counseling and surveillance of at-risk patients. A specific genotype-phenotype correlation is unlikely because of the heterogeneity of the mutations in the MEN1 gene.
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