|Year : 2019 | Volume
| Issue : 1 | Page : 8-11
Retinoblastoma in Onitsha, Nigeria
Sebastian N N Nwosu, Nonso E Okpala, Chinasa A Nnubia, Cyriacus U Akudinobi
Guinness Eye Center, Onitsha, Nigeria
|Date of Web Publication||4-Jul-2019|
Prof. Sebastian N N Nwosu
Guinness Eye Center, PMB 1534, Onitsha
Source of Support: None, Conflict of Interest: None
Objectives: This study aims to determine the incidence, pattern, and problems of management of retinoblastoma at the Guinness Eye Center, Onitsha, Nigeria. Materials and Methods: Case files of all patients with histology-proven retinoblastoma between October 2012 and September 2017 were reviewed. Information obtained included age, sex, disease duration, presenting features, and treatment. Results: There were 31 patients, 14 males (45.2%) and 17 females (54.8%), who had the disease in 38 eyes; age range was 5 months to 6 years; and median was 2.4 years. Disease duration was 3 weeks to 3 years and median was 8.8 months. Seven patients (22.6%) had bilateral disease, 11 (35.5%) had the disease only in the right eye, whereas 13 (41.9%) had the disease in the left eye; 32 (84.2%) eyes had no visual potential at presentation. The most common clinical features were leukocoria in 23 (60.5%) eyes and proptosis in 20 (52.6%). While all patients with advanced disease had enucleation or modified exenteration, only 15 (48.4%) accepted chemotherapy with two completing the full course and five not returning after the first course. Five (16.1%) had distant metastasis, namely, brain 2 (6.5%) and orbit, jaw, and skull 1 (3.2%) each. Conclusions: Retinoblastoma is seen at the Guinness Eye Center at the rate of about one case in 2 months. Most patients present late with proptosis and, in some cases, fungating necrotic tumor mass with distant metastases. There is a high default rate with treatment as only two patients completed the full course of chemotherapy.
Keywords: Incidence, Nigeria, pattern, retinoblastoma, treatment
|How to cite this article:|
Nwosu SN, Okpala NE, Nnubia CA, Akudinobi CU. Retinoblastoma in Onitsha, Nigeria. Niger J Ophthalmol 2019;27:8-11
| Introduction|| |
Retinoblastoma is the most common childhood intraocular malignancy. It is a tumor of the photoreceptors, which could be sporadic or hereditary. The hereditary disease is usually bilateral and constitute up to a third of the cases. Retinoblastoma threatens both the life and sight of the afflicted.
It occurs in 1:20,000 live births in the USA. In 1967, Kodilinye showed that it was relatively common in Nigerian children when he reported an incidence of 1:192 new patients in Ibadan, western Nigeria. Later, Abiose, working in Kaduna, northern Nigeria, documented an incidence of 1 in 500 children. Ezepue and Maduka-Okafor reported that retinoblastoma accounted for 77 out of 7619 admissions (1.01%) at the University of Nigeria Teaching Hospital, Enugu. Similarly, Adejor, in a 4-year review at the National Eye Centre Kaduna, reported an incidence of 1:1211 (0.08%) for retinoblastoma. Nwosu et al., in 1999, reported an incidence of 0.6% among under 5 children in Onitsha, eastern Nigeria. The annual incidence of retinoblastoma in Africa has been observed to exceed that of western countries. Surprisingly, Nwofor and Ukah, in a recent review of Nnewi (South East Nigeria) Cancer Registry, did not record any case of retinoblastoma.
The present study is a 5-year review of the incidence and pattern of retinoblastoma at the Guinness Eye Center, Onitsha, Nigeria. The Guinness Eye Center Onitsha is the ophthalmic wing of the Nnamdi Azikiwe University Teaching Hospital. It is the only publicly owned eye hospital in Anambra State and indeed in eastern Nigeria. Although there are eye units in some hospitals as well as private eye clinics in Anambra State and its environs, the Guinness Eye Center has the highest concentration of ophthalmic manpower and facilities in the state.
| Materials and Methods|| |
The case files of all patients diagnosed with retinoblastoma at the Guinness Eye Center Onitsha between July 2012 and June 2017 were reviewed. Only those with histology-proven retinoblastoma were analyzed. Information obtained included sociodemographic variables, clinical features, and treatment.
| Results|| |
There were 42 patients with diagnosis of retinoblastoma during the 5-year period. However, 11 patients were excluded because of lack of histological confirmation of the diagnosis. Therefore, 31 patients (38 eyes) were further analyzed.
During the study period, 31,019 new patients were seen out of which 5105 (16.5%) were children aged ≤15 years; 3476 (11.2%) were aged ≤10 years. Thus, retinoblastoma constituted at least 0.1% of all new patients, 0.5% of all children, and 0.9% of children aged ≤10 years.
Of the 31 patients, 14 (45.2%) were males and 17 (54.8%) were females. The age at presentation ranged from 5 months to 6 years with a median of 2.4 years. The median disease duration at presentation was 8.8 months, within a range of 3 weeks to 3 years. Twenty-four (77.4%) patients had uniocular retinoblastoma (11, 35.5% in the right eye only, and 13, 41.9% in the left); 7 (22.6%) patients had bilateral disease.
At presentation, 32 of the 38 eyes (84.2%) presented with features of advanced disease with these eyes having no visual potential. [Table 1] shows the clinical features. Leukocoria seen in 23 (60.5%) eyes and proptosis in 20 (52.6%) eyes were the most common presenting features; 16 (42.1%) eyes with proptosis also had fungating tumor masses. At examination under anesthesia, the tumor in the leukocoric eyes had occupied more than half the volume of the globe. Two (5.3%) eyes had hyphema secondary to neovascular glaucoma. [Table 2] shows the systemic metastasis of the tumor. Five (16.1%) patients were affected. One of the two patients with metastasis of the central nervous system also had episodes of seizures whereas the other had paraplegia. Treatment consisted of enucleation or exenteration along with chemotherapy (vincristine, cisplatin, and doxorubicin). Nine (29.0%) patients received chemotherapy with only two completing the courses [[Table 3]].
| Discussion|| |
The present study only dwelt on histology-proven cases of retinoblastoma. This is because retinoblastoma is known to mimic several pathologies including ocular tuberculosis, panophthalmitis, uveitis, and other causes of leukocoria., Apart from leukocoria, retinoblastoma could also present with either proptosis or phthisis bulbi as some of the cases in the present study have shown [[Table 1]]. Therefore, histopathologic and/or cytologic or molecular biologic techniques are required to confirm the diagnosis. The importance of histologic confirmation is further buttressed by the experience of Abdu and Malami who reported that 2% of the patients diagnosed as retinoblastoma in their study turned out to be toxocara granuloma on histologic examination.
It is likely that the incidence of the disease recorded in the present study is an underreporting as some of the cases excluded for lack of histology report may indeed be retinoblastoma. Retinoblastoma occurs most frequently in early childhood although Pam et al. reported a case of retinoblastoma in a 23-year-old man with a family history of the disease. The incidence of 0.9% among children aged ≤10 years may appear small. However, it needs be emphasized that this is the minimum incidence having discarded cases without histology confirmation and that at least one new patient with retinoblastoma presents to our hospital every 2 months.
In developed countries, most patients present early. In the present study, the median age of presentation was 2.4 years even when up to a quarter of the patients had bilateral disease. This compares with the experience in other parts of Africa., Lukusa et al. in Democratic Republic of Congo reported that the median age at hospital consultation by retinoblastoma patients was 2.4 years; Lukamba et al. while reviewing retinoblastoma in sub-Saharan Africa also reported that the median age at diagnosis was 3 years. These contrast with the experience in the USA where the mean age at hospital consultation was 18 months. Late presentation to hospital by retinoblastoma patients has been uniformly reported from different parts of Nigeria with reported mean age at presentation ranging from 2.3 to 3 years.,,, Being a retrospective study that relied on patients’ case notes, there are limitations. For instance, we were unable to specifically determine the reason(s) for late presentation. However, many factors including health-seeking behavior, parental knowledge and attitude, and sociocultural and economic issues may be at work. Occasionally, misdiagnosis may be a cause of delay. Late presentation is associated with poor prognosis; in the present study, 84.2% of the eyes had no visual potential at the time of presentation with 5 (13.2%) patients having distant metastasis that threaten their lives. The unhappy picture of necrotic fungating mass with distant metastasis remains largely unchanged since Kodilinye’s first report more than 50 years ago. Recent reports from other parts of Nigeria, and Africa,, uniformly report the poor outcome of retinoblastoma largely attributable to presentation in the hospital at the advanced stages of the disease.
In developed countries, the life and sight of many of these children are now salvaged.,,,,, But in our present circumstance, the surgeon-oculist is primarily concerned with palliation. Enucleation still remains the first-line treatment in our hospital despite recent advances in treatment such as intraarterial and intravitreal chemotherapy, transpupillary thermotherapy, cryotherapy, and radiotherapy.,,,,,
The poor compliance with treatment recorded in the present study is similar to the experience in other parts of Nigeria. From Lagos, Musa et al. reported that only six out of 28 patients offered enucleation or accepted modified exenteration with only six patients completing chemotherapy; in Kano, Abdu and Malami also documented that only two out of 39 patients completed chemotherapy. Treatment in these hospitals is not free even for children. Even with some subsidy, the hidden cost associated with hospitalization is enormous for the average Nigerian family. Thus, apart from sociocultural factors underlying late presentation and refusal of surgery, financial problem may be a principal reason for very low acceptance of chemotherapy. Sadly, it is obvious from our study and other recent studies in Nigeria, that the problems of management faced by Kodilinye more than half a century ago in Ibadan is still with us. Worse is our own lack of documentation where it matters leading to the absence of information on eye cancers in the Nnewi Cancer Registry.Management of retinoblastoma is multidisciplinary involving the ophthalmic surgeon, oncologist, pediatrician, and social worker.,,,, Early detection and quick referral should be the business of everyone involved in child care. Leukocoria (white pupil), which is one of the earliest clinical manifestations of the disease, was the presenting clinical feature in 60.5% of our patients [[Table 1]]. This compares with the experience in other parts of Africa,, and elsewhere where it was reported to be 56% to 72%. The populace including de facto leaders, parents, teachers, and midwives of all grades should be educated on the recognition and significance of the white pupil in an under 5 child and the need to refer such child for eye care.
This review leaves some unanswered questions, namely, the survival rate of retinoblastoma children in our environment, the home environment of the retinoblastoma patient, and the possibility of local oncogenic predisposing factor. A prospective study will hopefully address these challenges.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]