Endocrine tumours: progressive metastatic medullary thyroid carcinoma: first- and second-line strategies.

The treatment for metastasised medullary thyroid cancer is still a topic of discussion. One of the main challenges remains to find effective adjuvant and palliative options for patients with metastatic disease. The diagnostic and treatment strategies for this tumour are discussed and possible new developments commented. Approaches that target rearranged during transfection (RET) are preferable to those that target RET downstream proteins as, theoretically, blocking RET downstream targets will block only one of the many pathways activated by RET. Combining several agents would seem to be more promising, in particular agents that target RET with those that independently target RET signalling pathways or the more general mechanism of tumour progression.

Fewer cancer reoperations for medullary thyroid cancer after initial surgery according to ATA guidelines.

BACKGROUND: Surgery is still the only curative treatment for medullary thyroid cancer (MTC). We evaluated clinical outcome in patients with locoregional MTC with regard to adequacy of treatment following ATA guidelines and number of sessions to first intended curative surgery in different hospitals. METHODS: We reviewed all records of MTC patients (n = 184) treated between 1980 and 2010 in two tertiary referral centers in the Netherlands. Symptomatic MTC (palpable tumor or suspicious lymphadenopathy) patients without distant metastasis were included (n = 86). Patients were compared with regard to adequacy of surgery according to ATA recommendations, tumor characteristics, number of local cancer reoperations, biochemical cure, clinical disease-free survival (DFS), overall survival (OS), and complications. RESULTS: Adherence to ATA guidelines resulted in fewer cancer-related reoperations (0.24 vs. 0.60; P = 0.027) and more biochemical cure (40.9 vs. 20 %; P = 0.038). Surgery according to ATA-guidelines on patients treated in referral centers was significantly more often adequate (59.2 vs. 26.7 %; P = 0.026). Tumor size and LN+ were the most important predictors for clinical recurrence [relative risk (RR) 4.1 (size > 40 mm) 4.1 (LN+) and death (RR 4.2 (size > 40 mm) 8.1 (LN+)]. CONCLUSIONS: ATA-compliant surgery resulted in fewer local reoperations and more biochemical cure. Patients in referral centers more often underwent adequate surgery according to ATA-guidelines. Size and LN+ were the most important predictors for DFS and OS.

Outcomes of adrenal-sparing surgery or total adrenalectomy in phaeochromocytoma associated with multiple endocrine neoplasia type 2: an international retrospective population-based study.

BACKGROUND: The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2. METHODS: This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy. FINDINGS: 1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent. INTERPRETATION: The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.

Clinical relevance of 18F-FDG PET and 18F-DOPA PET in recurrent medullary thyroid carcinoma.

UNLABELLED: The transition from stable to progressive disease is unpredictable in patients with biochemical evidence of medullary thyroid carcinoma (MTC). Calcitonin and carcinoembryonic antigen (CEA) doubling times are currently the most reliable markers for progression, but for accurate determination, serial measurements, which need time, are required. We compared (18)F-FDG PET and (18)F-dihydroxyphenylanaline ((18)F-DOPA) PET with biochemical parameters and survival to assess whether these imaging modalities could be of value in detecting progressive disease. METHODS: We evaluated the outcome of (18)F-FDG PET or (18)F-DOPA PET with calcitonin and CEA doubling times in 47 MTC patients. A subgroup of patients was included in the whole metabolic burden (WBMTB) analysis, with determination of standardized uptake values and number of lesions. WBMTB of (18)F-DOPA PET and (18)F-FDG PET was compared with biochemical parameters. Furthermore, survival was compared with (18)F-DOPA PET or (18)F-FDG PET positivity. RESULTS: Doubling times were available for 38 of 40 patients undergoing (18)F-FDG PET. There was a significant correlation with (18)F-FDG PET positivity. Doubling times were less than 24 mo in 77% (n = 10/13) of (18)F-FDG PET-positive patients, whereas 88% (n = 22/25) of (18)F-FDG PET-negative patients had doubling times greater than 24 mo (P < 0.001). Between doubling times and (18)F-DOPA PET positivity, no significant correlation existed. (18)F-DOPA PET detected significantly more lesions (75%, 56/75) than did (18)F-FDG PET (47%, 35/75) in the 21 patients included in WBMTB analysis (P = 0.009). Calcitonin and CEA levels correlated significantly with WBMTB on (18)F-DOPA PET, but doubling times did not. (18)F-FDG PET positivity was a more important indicator for poor survival in patients for whom both scans were obtained. CONCLUSION: (18)F-FDG PET is superior in detecting patients with biochemical progressive disease and identifying patients with poor survival. Although (18)F-DOPA PET has less prognostic value, it can more accurately assess the extent of the disease in patients with residual MTC. Hence, both scans are informative about tumor localization and behavior. On the basis of these results, we designed a clinical flow diagram for general practice in detecting recurrent MTC.

The effects of four different tyrosine kinase inhibitors on medullary and papillary thyroid cancer cells.

CONTEXT: Medullary and papillary thyroid carcinoma (MTC and PTC) are two types of thyroid cancer that can originate from activating mutations or rearrangements in the RET gene. Therapeutic options are limited in recurrent disease, but because RET is a tyrosine kinase (TK) receptor involved in cellular growth and proliferation, treatment with a TK inhibitor might be promising. Several TK inhibitors have been tested in clinical trials, but it is unknown which inhibitor is most effective and whether there is any specificity for particular RET mutations. OBJECTIVE: We aimed to compare the effect of four TK inhibitors (axitinib, sunitinib, vandetanib, and XL184) on cell proliferation, RET expression and autophosphorylation, and ERK activation in cell lines expressing a MEN2A (MTC-TT), a MEN2B (MZ-CRC-1) mutation, and a RET/PTC (TPC-1) rearrangement. DESIGN: The three cell lines were cultured and treated with the four TK inhibitors. Effects on cell proliferation and RET and ERK expression and activation were determined. RESULTS: XL184 and vandetanib most effectively inhibited cell proliferation, RET autophosphorylation in combination with a reduction of RET expression, and ERK phosphorylation in MTC-TT and MZ-CRC-1, respectively. TPC-1 cells showed a decrease in RET autophosphorylation after treatment with XL184, but no effect was observed on ERK activation. CONCLUSION: There is indeed specificity for different RET mutations, with XL184 being the most potent inhibitor in MEN2A and PTC and vandetanib the most effective in MEN2B in vitro. No TK inhibitor was superior for all the cell lines tested, indicating that mutation-specific therapies could be beneficial in treating MTC and PTC.

[Medullary thyroid cancer, a tumour with many appearances]. / Medullair schildkliercarcinoom, een tumor met vele gezichten.

Medullary thyroid cancer (MTC) has a variable clinical presentation. We present 3 patients with this endocrine tumour. The first patient, a 41-year-old woman complaining of diarrhoea, a painful abdomen, weight loss and sensibility disorders in both legs, had metastases of MTC in the spine, with little progression during 2 years of follow-up. The second patient, a 64-year-old woman suffering from a painful nodule in the neck and a painful shoulder, was diagnosed with MTC and liver, lung and bone metastases. She died after 14 months due to progressive disease. The third patient, an 81-year-old woman with hyperparathyroidism, was coincidentally diagnosed with MTC after goitre surgery at the age of 67. When she was evaluated for rising calcitonin levels, a pheochromocytoma was found. RET mutation analysis confirmed a MEN2A syndrome. Current diagnostic procedures of MTC may include positron emission tomography with 18F-deoxyglucose (FDG-PET) and 18F-diphenylalanine (DOPA-PET). MTC is usually treated surgically. Tyrosine kinase inhibitors appear to offer potential new therapeutic possibilities.