4. Discussion
Cancer is an abnormal cell proliferation that is beyond the regulatory
mechanisms, invading and destroying the tissues in which they develop,
capable of disseminating early in the body in children, and susceptible
to recurrence after treatment [14]. In the absence of a national
cancer registry in the Democratic Republic of Congo, data on cancer
epidemiology and mortality in several developing countries, the
incidence of this condition is expressed only in relative frequencies
[15].
The number of cases per year in our study was lower than in the
literature in general and particularly in the DRC capital [16].
The average age reported in our study was (5.2 - 3.9 years). In
sub-Saharan Africa, the average age was 6.7-4.3 years, which is slightly
higher than the age found in our environment (1) [17, 18]. The age
group most affected is under 9 years of age and accounts for 57.6% of
cases, but the age-related case-to-population curve indicates a gradual
increase with age. The average age is 5.2 - 3.9 years, and it is
slightly higher for men (5.2 years) than for women (4.9 years). This is
approximately a decade younger than patients in developed countries, and
similar to developing countries. This could be favored by a young
population, the predominance of factors favoring such as infections,
poor hygienic conditions etc. In 2013, Osama et al in Saudi Arabia found
similar results [19]. The number of cancer cases in Lubumbashi
appears to increase each year. It should be noted that histologically
confirmed childhood cancers are still insufficient. The average age at
the onset of the disease was (4.2-3.4 years). While the average age in
the male sex was 5.2 years was statistically higher than the age of the
girls (4.9 years; p - 0.0237).
We observed a male predominance (sex ratio H/F of 1.3). According to
Steliarova-Foucher et al. [4], this strong male representation is
explained by the social impact of cancer in the male subject in the
African environment who should be responsible for family than in the
daughter. The H/F sex ratio noted in our study was slightly lower than
that reported in the Algerian and French studies [16-17] but was
consistent with that found by Aléine Budiongo et al. In Kinshasa 2020
and Newton et al in 1996 found similar results [20,21].
The study shows a large delay between the onset of the disease and the
first consultation 33.5-7.1 weeks (11-day and 210-week interval). In
Africa, childhood cancer is still too often stigmatized because of
ignorance of the disease or an often-late diagnosis and beliefs around
the disease. Childhood cancer is often taken as mystical, and a
significant number of households in our community have brought children
to traditional practitioners first.
In our study, the cancers frequently encountered in our environment were
retinoblastoma which alone accounted for 29 (29.2%) nephroblaostoma
follow-up 23 (23.3%) lymphomas of all forms 13 (13.2%). Studies in
Congo Brazzaville and Kinshasa have shown a predominance of
Retinoblastoma (about 30%) [9]. Other types of cancers were
presented but to a small extent, leukemias (7.1%); bone tumors (1.9%)
and soft tissue sarcoma (0.9%). Of the histological type by sex in our
environment, the male sex had retinoblastoma as the most common cancers
(16.1%) followed by nephroblastoma (10.9%) leukemia (7.4%). In
contrast, in the female sex, the most common cancers were retinoblastoma
(13.1%) lymphoma (8.1%). There are cancers associated with other
factors than the most incriminated factor in embryonic development by
comparing it to developed countries. Other tumours that may be
associated with lifestyle. Cancers of the nervous system are also
relatively less common. This can be explained by a lack of
state-of-the-art equipment (brain imaging) in our environment and also
by a very small number of qualified personnel for the identification of
early diagnosis and certainty. These results are similar to those of
other developing countries [22]. In contrast, data from Abidjan
(Ivory Coast), Niamey (Niger), Ibadan (Nigeria), and Gambia show a low
incidence rate of leukemia per reported to European countries
[16,23,24]. The histological type of lymphomas in our environment
comes in third place with a large number of Burkitt lymphoma (8.8% of
NLL), occupying the 1st rank among different types of lymphomas. Uwizeye
et al in Rwanda in 2013 found Burkitt’s lymphoma to be rare in Rwanda
[25]. Ngendahayo et al in Rwanda, found that diffuse
centroblastic-centrocytic lymphoma was the most common (35% of NHS) and
burkitt lymphoma was very rare (5 cases) [25]. This situation is
different from our series. This is probably because in our community
families have consulted more for Burkitt than the case observed in
Rwanda.
A good number of children 81.9% had received curative chemotherapy
during the period of our study. We recorded (35.4%) death toll. These
results are almost similar to studies conducted in Africa [22], but
remain far different from studies conducted in developed countries where
mortality rates for childhood cancers is declining significantly
[26]. This could be due to a delay in diagnosis, a lack of qualified
staff for care, a lack of specialized oncology units and also access to
care, which remain a great burden for most households.