Retinoblastoma: Socio-Demographic, Clinical and Therapeutic Aspects in the Hemato-Oncology Unit of the Department of Pediatrics of Donka National Hospital, Guinea

Introduction: Retinoblastoma is one of the pediatric malignancies and its treatment is still challenging. The objective of this study was to highlight the sociodemographic, clinical, and therapeutic aspects of retinoblastoma at the Donka Paediatric Haematology/Oncology unit in Donka university hospital, Guinea, and thereby highlight the conditions of this malignancy in this coun-try. Methods: This was a retrospective study over 3 years (January 1, 2017 to December 31, 2019). The study population was all retinoblastoma patients who were treated in this unit. Socio-demographic, clinical, and therapeutic data were analyzed. Results: Out of 210 pediatric patients followed up for cancer in this unit during the period, retinoblastoma accounted for 46 (22%). The patient age at diagnosis was 35.17 months (range: 3 - 132 months). At admission, metastases were observed in 16 patients (35%): 14 with brain metastases and 2 with lymph node metastases. Preoperative chemotherapy was employed in nancy and social education/message as such is necessary.


Introduction
Retinoblastoma is a malignant tumor that develops at the expense of embryonic retinal cells or retinoblasts [1]. It affects infants and young children in general, before the age of 5 years [2] [3] [4]. Globally, the overall incidence of retinoblastoma is estimated at 1/16,000 live births, or about 8000 new cases each year, including at least 2000 new cases in Africa [5]. The incidence of retinoblastoma is unevenly distributed. It is higher in low-income countries than in high-income countries [6].
There are two forms of retinoblastoma: the sporadic form and the hereditary form. Sporadic cases are always unilateral and account for 60% of patients, with a median age at diagnosis of about two years, while the hereditary forms are mostly bilateral and account for 40% of patients, with a median age at diagnosis of about one year [2].
The diagnosis of retinoblastoma is essentially clinical and is most often revealed by two warning signs: Leukocoria and strabismus. These signs allow an early diagnosis by a simple examination of the fundus. Imaging plays an important role in the diagnosis of atypical or advanced forms of retinoblastoma with an inaccessible fundus [7].
In industrialized countries, the cure rate is about 95%, the vast majority of cases are diagnosed at an early stage of the disease, whereas in poor countries life-threatening retinoblastoma is a major challenge and is due to late diagnosis [5].
The objective of this study was to highlight the socio-demographic, clinical and therapeutic aspects of retinoblastoma at the Pediatric Hematology and Oncology Unit in Donka of Guinea.

Methods
The pediatric hematology and oncology unit of Donka national hospital in Guinea was the setting for this study. This unit is located on the grounds of Donka National Hospital republic of Guinea. It has a capacity of 8 inpatient beds and a day hospital. The staff includes 3 onco-pediatricians, 5 state nurses and 1 technical health worker. The hematology and oncology unit is supported by the The study population was all retinoblastoma patients followed in the unit, and whose records were usable (records of patients who have completed a full retinoblastoma extension workup). Patients who were lost to follow-up (Patients who have not been heard from and who have not undergone an extension workup) were not included in the study.
The variables studied were: • Socio-demographic data (sex, age, place of residence of patients); • Clinical data (mode of discovery, reason and time of consultation, itinerary, stage of the disease, laterality, fundus results); • Paraclinical data (biology, ultrasound and brain orbital CT data).
The data were collected on a pre-established and validated survey form and entered into Word and Excel and then analyzed on Epi info 7.2.

Ethical Considerations
The agreement of the service managers was obtained before the surveys began. A working protocol was drawn up and validated by the hospital authorities and the pediatric chair. The confidentiality of the data collected was respected and the personal information collected remained confidential.

Socio-Demographic Aspects
Out of 210 patients followed for cancer we registered 46 cases of retinoblastoma (21.9%) ( Table 1). The patients were distributed as follows: 13 in 2017 (28.2%), 16 in 2018 (34.8%) 17 in 2019 (37%). The average age of our patients was 35.17 months with extremes of 3 months and 132 months. There were 52.2% girls and 47.8% boys with a B/G sex ratio of 0.9. The age range of 25 to 59 months was the most representative with 26 cases (56.52%). For 31 patients there was no notion of consanguinity between the 2 parents (67.3%). Eleven patients had relatives with a 2nd degree consanguinity (24%). Four patients had a 1st degree consanguinity (8.7%).

Clinical Aspects
The median time to visit was 165 days with extremes of 7 days and 4 years.    [19]. Follow-up of children with a family history of retinoblastoma is necessary for early detection.
The unilateral form predominated in our study with 87% of the cases against 13.0% for the bilateral form. Unilateral retinoblastoma is the most common form as reported in the studies by Singh et al. in 2018 [20]. The management of retinoblastoma is multidisciplinary. It involves the pediatric oncologist, the ophthalmologist, the radiotherapist, the ocularist, the anatomopathologist, the psychologist, the radiologist. Our study has some limitations: we did not have enough recurrences to assess the survival of our patients. As the study period was from January 2017 to December 2019, some of our patients were still being treated at the time of inclusion. For these patients, we were unable to assess the evolution of their pathology.
We had 36.96% remission. Berete et al. [10] in Ivory Coast in 2018 reported a remission rate of 25%. This result could be explained not only by a delay in diagnosis and treatment but also by frequent drug stockouts.

Conclusion
In this region of Guinea, retinoblastoma is the most common ocular tumor in children. Its diagnosis is easy: strabismus and leukocoria are the early signs of reti-noblastoma. The prognosis depends on how early the diagnosis is made.
Physicians, care-givers, and family members should be aware of the nature of this malignancy and social education/message as such is necessary.