Leukamia in Kenya

Abstract

The main objective of the study was to show that leukaemia was more common in Kenyan Africans than has been the belief from impressions. Literature review revealed that there ave been sporadic case reports of leukaemia in Kenyan Africans since 1924. However, increasing leukaemia documentation has only featured in the seventies because f the progressively developing awareness and interest in the disease (Table 3, page 20). This retrospective and prospective study covered 456 cases of all types of leukaemia diagnosed at the Kenyatta National Hospital between 1971 and 1977. Those cases admitted to this hospital were further fully investigated and treated if they did not die immediately. Then several clinicopathological variables and biodata were analysed in all the cases. The overall n at.LonaL crude incidence is 0.5 cases per 100,000, with a maximum tribe-specific incidence being 1.2 cases per 100,000. Childhood (below 15 age group) leukaemia accounted for 28% of all types of leukaemia, giving an incidence of 0.3 cases per 100,000, in contrast to the adult incidence of 0.7 cases per 100,000. However, 48% of all acute leukaemias occurred in childhood as compared with only 4.7% of the chronic types. There is a peak occurrence of all types of leukaemia in the first decade of life, with a minor secondary peak in the sixth decade. The nadir appears in the 4th and 5th decades. There is an apparent deficit of acute lymphocytic leukaemia in the 0-4 year age group but acute myclogenous presents with a peak in the second decade of life. Chronic granulocytic has tl1e highest prevalence in the 20-40 year age-group and chronic lymphocytic in the 40-70 year period. There is an overall male to female ratio of 1.47:1, but the childhood ratio is 1.7:1. Tribal distribution correlates with proximity of various tribes to medical services and there is no obvious geographical pattern.

Leukaemia typing shows that the myeloid leukaemias are twice as frequent as the lymphocytic types, with the following distribution: AML (including myclomonocytic) - 31.6%; ALL (including acute prolymphocytic) -14.9%; ALSCL - 5.5%; AMoL - 3.3%; AUL - 0.9%; CGL - 28.5%; LL - 15.3%; ALSCL emerges as an important entity, which occurs maximally in the 5-9 year age~group. I The general behaviour of leukaemia sho1\1sno gross difference from what is known about leukaemia from elsewhere. However, subtle but important features stand out. The majority of patients present with advanced disease,

most often in terminal stages, as is evidenced by the high mortality rate within the first month after diagnosis, frequent gross organomegaly, severe anaemia and thrombocytopenia, hyperleucocytosis (37% over 200xl09/l; 42% over 30xl09/1,) or marked blastaemia with the generally poor clinical performance. There is a high frequency (23%) of facial chloromatous presentation in childhood AML and AM-ML, which often simulate Burkittc's lymphoma. Cases of acute leukaemia masquerading as rheumatoid arthritis or aplastic anaemia are not uncommon. There were remission induction rates of 69% for all the acute leukaemias, in which ALL had 85% and AML - 54%. None of the patients with AMoL or AUL attained remission. Sixty three percent of AML, patients died within one mom.h and almost all were dead within 12 months after .- diagnosis. Only 32% of ALL patients died within one month, and 37% survived for more than 12 months (Fig. 20). In childhood acute leukaemia, about 90% of ALL attained. remission status, only 10% died within one month and all had a median survival of 15 months. Similarly.>60% of children with AML went in to remission and all had a median survival of only 8 months. The chronic leukaernias showed orthodox features although CLL appeared to have a poorer outlook than CGL (Fig. 20).

The quality of survival, even if reasonable, was interrupted by a diversity of infections which often caused death. Autopsy in 76 cases confirmed that death was due to haemorrhage in 24%; infection - 20%; multiple causes - 16%; other causes, including organ failure - 30%. No disseminated fungal infection was encountered. The problems of diagnosis with consequent underdiagnosis of leukaemia in Kenya are highlighted. Effective management of this disease,in Kenya, is beset with problems of ignorance by the public, patients, as well as the lack of medical team work and the prohibitive socioeconomic factors. Thus, leukaemia is a common disease in Kenya, as it also accounts for 4% of medical and paediatric admissions. Its behaviour is, in general, the same as is known about it elsewhere , although it appears to be more aggressive, probably due to the late presentation of patients. There is urgent need for establishing its precise incidence by comnunity surveys and also a thorough study of associated aetiological factors. For the present, acute awareness of its existence is mandatory if early diagnosis, which is a prerequisite to successful management, has to be made.