Chemotherapy trials in malignant pheochromocytoma: report of two patients and review of the literature

RNF20 and RNF40 regulate vitamin D receptor-dependent signaling in inflammatory bowel disease

Despite the identification of several genetic factors linked to increased susceptibility to inflammatory bowel disease (IBD), underlying molecular mechanisms remain to be elucidated in detail. The ubiquitin ligases RNF20 and RNF40 mediate the monoubiquitination of histone H2B at lysine 120 (H2Bub1) and were shown to play context-dependent roles in the development of inflammation. Here, we aimed to examine the function of the RNF20/RNF40/H2Bub1 axis in intestinal inflammation in IBD patients and mouse models. For this purpose, intestinal sections from IBD patients were immunohistochemically stained for H2Bub1. Rnf20 or Rnf40 were conditionally deleted in the mouse intestine and mice were monitored for inflammation-associated symptoms. Using mRNA-seq and chromatin immunoprecipitation (ChIP)-seq, we analyzed underlying molecular pathways in primary intestinal epithelial cells (IECs) isolated from these animals and confirmed these findings in IBD resection specimens using ChIP-seq.The majority (80%) of IBD patients displayed a loss of H2Bub1 levels in inflamed areas and the intestine-specific deletion of Rnf20 or Rnf40 resulted in spontaneous colorectal inflammation in mice. Consistently, deletion of Rnf20 or Rnf40 promoted IBD-associated gene expression programs, including deregulation of various IBD risk genes in these animals. Further analysis of murine IECs revealed that H3K4me3 occupancy and transcription of the Vitamin D Receptor (Vdr) gene and VDR target genes is RNF20/40-dependent. Finally, these effects were confirmed in a subgroup of Crohn's disease patients which displayed epigenetic and expression changes in RNF20/40-dependent gene signatures. Our findings reveal that loss of H2B monoubiquitination promotes intestinal inflammation via decreased VDR activity thereby identifying RNF20 and RNF40 as critical regulators of IBD.

Patient with inoperable pheochromocytoma

Malignant pheochromocytoma is a tumour with a very low incidence that occurs sporadically or in the presence of multiple endocrine neoplasia. We present the case of a woman with a sporadic occurrence of pheochromocytoma diagnosed in the phase of multiple dissemination in the abdominal cavity and overexpressing adrenaline, noradrenaline, and dopamine. Local transarterial chemoembolization and systemic treatment with lanreotide resulted in a very good response, a decrease in the production of catecholamines for 12 months and a partial decrease for another 8 months, with stabilization of disease determined by imaging. Systemic treatment with tegafur resulted in disease stabilization lasting 50 months, after which the drug was discontinued because of adverse effects. Maintenance therapy with lanreotide continues, and no disease progression has been observed for 4 months. The treatment algorithm for such patients is multidisciplinary and must always take into account the current scope of the disease, intercurrence, and the general condition of the patient.

Treatment of malignant pheochromocytoma

Pheochromocytoma (PCC) is a rare disease, mainly sporadic, but also associated with some familial disorders, with a malignancy frequency of approximately 10%. Only the presence of distant metastases, derived from large pleomorphic chromaffin cells, is widely accepted as a criterion of malignancy. Variable symptoms may be caused by production and release of catecholamines. Since there is no curative treatment for malignant PCC and due to its unfavorable prognosis, assuring quality of life is one of the main therapeutic objectives. Besides a long-term medical treatment of symptoms using selective alpha-1 blockers and nonselective, noncompetitive alpha- and/or beta-blockers, debulking surgery is the first treatment step. In case of a sufficient uptake of (123)I-MIBG treatment with targeted radiation therapy, use of (131)I-MIBG is an option as an adjuvant therapy, following debulking surgery. Chemotherapy should be applied to patients without positive MIBG-scan, with no response to (131)I-MIBG or progression after radionuclide treatment, and especially in cases with high proliferation index. The most effective chemotherapy regimen appears to be the CVD-scheme, including cyclophosphamide, vincristine, and dacarbazine. The so-called targeted molecular therapies with treatment combinations of temozolomide and thalidomide, or sunitinib monotherapy, and novel therapeutic somatostatin analogues have shown promising results and should thus encourage clinical trials to improve the prognosis of metastatic PCC. Within this review the current treatment modalities and novel molecular strategies in the management of this disease are discussed and a treatment algorithm is suggested.

Clinical review: Current treatment of malignant pheochromocytoma

CONTEXT

Pheochromocytomas are rare tumors of predominantly adrenal origin that often produce and secrete catecholamines. Malignancy occurs in a variable percentage of cases depending on genetic background and tumor location. Definitive diagnosis relies on the detection of distant metastases. Treatments for malignant pheochromocytoma include surgical debulking, pharmacological control of hormone-mediated symptoms, targeted methods such as external irradiation, and systemic antineoplastic therapy. Different agents and protocols for this purpose are reviewed, and their therapeutic potential is discussed.

EVIDENCE ACQUISITION

Literature on antineoplastic therapies for malignant pheochromocytoma was identified by searching the PubMed database with restriction to articles published in English during the past 30 yr.

EVIDENCE SYNTHESIS

Because of the rarity of the condition, no randomized clinical trials concerning the treatment of malignant pheochromocytoma have been performed. The strategy established best is [131I]meta-iodobenzylguanidine (MIBG) therapy, which is well tolerated. Similar to cytotoxic chemotherapy with cyclophosphamide, vincristine, and dacarbazine, MIBG can induce remission for a limited period in a significant proportion of patients. Octreotide as a single agent seems to be largely ineffective.

CONCLUSIONS

MIBG radiotherapy and cyclophosphamide, vincristine, and dacarbazine chemotherapy are comparable with respect to response rate and toxicity. It is unclear whether combining both can improve the outcome. Future developments may include new multimodal concepts with focus on inhibition of angiogenetic factors and heat shock protein 90. Any present or new therapeutic approach must take into account the highly variable natural course of the disease.

Pheochromocytoma in pregnancy: case report and review of the literature

Pheochromocytoma is a rare disease that may occur during pregnancy. Only a few hundred cases have been published in the literature. Manifestations include hypertension with various clinical presentations, possibly resembling those of pregnancy-induced hypertension, or pre-eclamptic toxemia. Differentiation of these conditions is not always feasible, thus creating a serious risk, because fetal and maternal morbidity and mortality are far higher with pheochromocytoma. Biochemical measurements of catecholamines and their metabolites are apparently a convenient way to establish diagnosis during pregnancy, inasmuch as interpretation of radiological evaluation is complicated by the gravid uterus, and might even be potentially dangerous due to the use of ionizing radiation. More sophisticated methods for evaluation are not always practical during pregnancy. Medical treatment aims at controlling symptoms, mandating the use of alpha- and beta-receptors blockade medication. Surgical intervention is the only possible curative method available, but the critical issue is probably to identify the exact timing during the course of pregnancy for such intervention, or the ability to control symptoms until delivery. Although malignant transformation of pheochromocytoma have been reported, it is extremely uncommon. The overall prognosis is mainly affected by early diagnosis, and multidisciplinarian management.

Malignant pheochromocytoma: a series of 14 cases observed between 1966 and 1990

We report 14 patients (9 males, 5 females) aged 15-59 years, treated for malignant pheochromocytoma. These patients were observed during the 1966-1990 period along with 68 other patients presenting benign pheochromocytomas. From the initial general presentation of the 14 patients, two groups could be individualized. In seven patients, the initial presentation seemed benign. After the excision, the recovery was complete, but patients recurred on average 7.8 yr later (range 1-22 yr). Tumors were intraadrenal in six cases (5 single, 1 bilateral) and extraadrenal in one case. In the seven remaining patients, malignancy was evident from the first examination. The tumors were intraadrenal in 2 cases, extraadrenal in 5 cases. Frequency of extraadrenal locations (6/14) was in this series significantly higher than in benign forms (9/68). Diagnosis of malignancy was based on metastases in 12 cases (lymph nodes in 5, bones in 5, liver in 4, lung in 2, brain in 1) and on peritumoral extension in 2 cases. No biological specificity was detected in urinary excretion of catecholamines or its metabolites. In 6 patients so far studied, an uptake of 131I MIBG was found in the tumor and/or metastases. Four patients received therapeutic doses of 131I MIBG and in three of them, this treatment led to a good result within a follow-up range of 12 to 66 months.(ABSTRACT TRUNCATED AT 250 WORDS)

High-voltage irradiation and combination chemotherapy for malignant pheochromocytoma

A 29-year-old man with metastatic extraadrenal pheochromocytoma developed paraplegia which reversed completely after megavoltage irradiation of the dorsolumbar spine. Later, treated with cyclophosphamide, vincristine, and dacarbazine, he had a temporary decrease in plasma norepinephrine concentration, a partial recalcification of bone lesions, and a decrease in the need for antihypertensive treatment for 12 months. Irradiation and combination chemotherapy should be evaluated further in the management of malignant pheochromocytoma.