Biomedical subjects

Isabelle Aerts

Publications and source records attributed to Isabelle Aerts.

6 recordsLinked to original sources

PubMed2025

A functional assay to classify RB1 variants of uncertain significance.

PURPOSE: The RB1 gene encodes the retinoblastoma protein (pRB) playing a major role in cell cycle control, particularly by its interaction with E2F transcription factors. Familial forms of retinoblastoma are caused by germline pathogenic variants in the RB1 gene predisposing to retinoblastoma and other tumors. By analyzing the RB1 gene in patients with retinoblastoma, we found that missense variants often remain variants of uncertain significance (VUS). METHODS: To classify RB1 VUS, we developed a functional assay evaluating their impact on the ability of pRB to inhibit the activity of the E2F1 promoter, with a luciferase reporter gene. A set of 14 pathogenic/likely pathogenic and benign/likely benign RB1 variants was used for validation. RESULTS: We tested 16 VUS detected in patients with retinoblastoma and found that 9 VUS reduced the ability of pRB to inhibit E2F1 promoter. Among them, the (RB1) c.2263T>G p.(Phe755Val) variant showed a reduced level of pRB on Western blot, suggesting a defect in pRB stability. By applying the criterion PS3_moderate of the American College of Medical Genetics and Genomics/Association for Molecular Pathology classification to this functional assay, 5 of the 9 VUS with functional impact could be classified as likely pathogenic. CONCLUSION: This functional assay can improve the molecular diagnosis of retinoblastoma predisposition by a better determination of pathogenic/likely pathogenic RB1 variants.

Humans↗

PubMed2006

Retinoblastoma.

Retinoblastoma is a rare eye tumor of childhood that arises in the retina. It is the most common intraocular malignancy of infancy and childhood; with an incidence of 1/15,000-20,000 live births. The two most frequent symptoms revealing retinoblastoma are leukocoria and strabismus. Iris rubeosis, hypopyon, hyphema, buphthalmia, orbital cellulites and exophthalmia may also be observed. Sixty per cent of retinoblastomas are unilateral and most of these forms are not hereditary (median age at diagnosis two years). Retinoblastoma is bilateral in 40% of cases (median age at diagnosis one year). All bilateral and multifocal unilateral forms are hereditary. Hereditary retinoblastoma constitutes a cancer predisposition syndrome: a subject constitutionally carrying an RB1 gene mutation has a greater than 90% risk of developing retinoblastoma but is also at increased risk of developing other types of cancers. Diagnosis is made by fundoscopy. Ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) scans may contribute to diagnosis. Management of patients with retinoblastoma must take into account the various aspects of the disease: the visual risk, the possibly hereditary nature of the disease, the life-threatening risk. Enucleation is still often necessary in unilateral disease; the decision for adjuvant treatment is taken according to the histological risk factors. Conservative treatment for at least one eye is possible in most of the bilateral cases. It includes laser alone or combined with chemotherapy, cryotherapy and brachytherapy. The indication for external beam radiotherapy should be restricted to large ocular tumors and diffuse vitreous seeding because of the risk of late effects, including secondary sarcoma. Vital prognosis, related to retinoblastoma alone, is now excellent in patients with unilateral or bilateral forms of retinoblastoma. Long term follow-up and early counseling regarding the risk of second primary tumors and transmission should be offered to retinoblastoma patients.

Child, Preschool↗

PubMed2006

The transmanubrial approach: a new operative approach to cervicothoracic neuroblastoma in children.

BACKGROUND: Cervicothoracic neuroblastoma originates from the cervical sympathetic nerves and ganglia and thus presents a problem when dissecting the vascular and nervous elements of the subclavian region. The standard operation is based on thoracotomy or dual cervicotomy/thoracotomy, but these approaches do not provide optimal control of the subclavian vessels. We report our experience in children with cervicothoracic neuroblastoma by using a technique usually performed for apical lung cancer. METHODS: Four patients with localized cervicothoracic neuroblastoma with no N-myc amplification were resected after chemotherapy by this approach. The anatomic evaluation was performed preoperatively with angio-magnetic resonance imaging. This transmanubrial approach, performed through a manubrial L-shaped transection and first costal cartilage resection, affords excellent access to the subclavian region with safe control of the vessels and nerves and exposure of the first 4 thoracic intervertebral foramina. RESULTS: Removal of more than 90% of the tumor was possible in all cases. The postoperative course was uneventful in 3 cases, and the fourth patient with a left-sided tumor had a transient chylothorax. No recurrence occurred with a follow-up period of 8 to 32 months. CONCLUSIONS: The transmanubrial approach is an osteomuscular-sparing technique that seems particularly suitable for the treatment of these tumors, which require a resection that is as complete as possible to avoid postoperative chemotherapy and tumor relapse.

Cervical Vertebrae↗

PubMed2005

Hypercalcemia and childhood cancer: a 7-year experience.

Hypercalcemia is a rare but potentially fatal complication during the management of childhood cancer. The treatment of severe hypercalcemia in children has not been clearly defined. The authors present a retrospective series of 16 children (11 boys and 5 girls) with severe hypercalcemia (>/=2.9 mmol/L) treated between 1997 and 2004 for malignancy. Median serum calcium level was 3.14 mmol/L. Hypercalcemia was present at the initial diagnosis of cancer (eight patients) or occurred during treatment (five patients) or during relapse (three patients). Three children had several episodes of hypercalcemia. All children were treated by hydration for a median of 7 days (range 2-12 days). Eight patients received intravenous pamidronate. The other treatments were adapted to the mechanism of hypercalcemia. Serum calcium levels were lowered to below 3 mmol/L after a median of 2 days and to below 2.7 mmol/L after a median of 4 days after starting treatment. Pamidronate was well tolerated apart from one case of multifactorial renal failure. Intravenous pamidronate is a safe and effective treatment for severe cancer-related hypercalcemia in children. Specific therapy must be initiated as soon as possible. Serum calcium levels must be monitored for a fortnight after administration of pamidronate due to the risk of hypocalcemia.

Adolescent↗

PubMed2004

Outcome of second malignancies after retinoblastoma: a retrospective analysis of 25 patients treated at the Institut Curie.

Retinoblastoma is usually curable in developed countries. The morbidity and mortality of patients with hereditary retinoblastoma is still threatened by the occurrence of secondary tumours. Between 1971 and 1988, 427 patients with retinoblastoma were treated in the ophthalmologic, paediatric and radiotherapy departments of the Institut Curie. In this study, we report the clinical and therapeutic features and the outcome of 25 patients treated for a second malignant neoplasm, diagnosed between 1997 and 1999 at the Institut Curie. The median time interval between the diagnosis of retinoblastoma and SMN was 11.2 years (range 3.8-20.6 years). Histopathological diagnoses included: 12 osteosarcomas, 12 soft tissue sarcomas and, 1 malignant oligodendroglioma. The second malignant neoplasm was located inside the radiation field in 21 cases and outside in 4. Twenty three patients received pre-operative chemotherapy. Surgery was performed in 16 patients. Post-operative chemotherapy was administered in 12 patients and external beam radiotherapy was used in 2 patients. Response to treatment was evaluable in 24 patients: complete remissions were observed in 14/24, partial remissions in 2/24 and progressive disease in 8/24. Nineteen patients died. Six are still alive, with 4 in complete remission (median follow-up 8.8 years; range 5.8-13.9 years). Despite aggressive therapy, the prognosis of patients with second malignant neoplasm occurring after retinoblastoma is very poor. It is important to provide information to retinoblastoma patients regarding the risk of a second tumour as this may facilitate an early tumour detection.

Child, Preschool↗

PubMed2003

Effectiveness of chemotherapy in rhabdomyosarcoma: example of orbital primary.

The survival of patients with rhabdomyosarcoma has been progressively improved with successive protocols due to the development of multidisciplinary management and the data accumulated by international groups. Orbital rhabdomyosarcoma represents 10% of all cases and affects young children (median age: 6.8 years). It is a chemosensitive and radiosensitive tumour. Chemotherapy is designed to decrease the indications for local therapy (mainly radiotherapy) responsible for a high rate of sequelae (cosmetic, functional or secondary cancer). According to the International Society of Paediatric Oncology guidelines, local therapy is not indicated as first-line treatment in case of complete remission after chemotherapy. The 10-year survival of children with non-parameningeal orbital rhabdomyosarcoma is currently 87% and identical survivals are reported by the various collaborative groups despite the use of different treatments. Despite clinical trials demonstrating the efficacy of many types of chemotherapy (cisplatin, etoposide, doxorubicin, dacarbazine), the value of adding these drugs to combination chemotherapy comprising of an alkylating agent (cyclophosphamide or ifosfamide), vincristine and dactinomycin has not been formally demonstrated in terms of survival benefit for children with rhabdomyosarcoma. The authors review these various results and compare the current guidelines for the management of orbital rhabdomyosarcoma recommended by North American and European groups.

Antineoplastic Combined Chemotherapy Protocols↗