Introduction: Hematologic malignancies remained a major global public health issue and the leading cause of global tumor burden. It significantly affects patients' overall health-related quality of life, financial toxicity, physical distress, and mental health challenges. So this study is aimed to estimate burden of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter.

Method And Materials: Both manual and electronic searches were used to extract studies for this meta-analysis from PubMed, Google Scholar, Scopus, DOAJ, Web of Science, and Google databases were utilized to identify the eligible articles. Then identified articles were exported into EndNote software used to export, organize, and review, the eligible articles. The quality of studies was assessed by using the Newcastle-Ottawa Scale quality appraisal tool for prevalence study. Meta-analysis was carried out using a random-effects method using the STATA™ Version 14 software.

Result: Nine included studies with a total of 31, 564 participants enrolled in this study. According to this study the pooled proportion of malignant hematological disorders in Ethiopia was found to be 8.47% (95% CI: 5.28-11.65) with range of 2.8%-17.2%. The highest prevalence of hematological malignancy is 11.92 % (95% CI: 4.30- 19.54) was seen in northern region, and the lowest is 5.82 % (95% CI: 1.78.-9.86) was seen in central region. 

Conclusion: According to these findings the pooled prevalence of malignant hematological disorders substantial in Ethiopia. Also, the findings highlight marked geographic disparities. So strengthening of hematologic diagnostic and treatment services are essential to ensure earlier detection and better management of hematologic malignancies across the country.

Malignant hematological disorders are cancers of the blood, bone marrow, and lymphatic system, primarily including leukemia, lymphoma, and multiple myeloma. They arise from abnormal blood or bone marrow cells and can originate from either the myeloid lineage (such as in acute myeloid leukemia [AML]) or the lymphoid lineage (such as lymphoma and chronic lymphocytic leukemia [1].

Patients with hematological malignancies were more likely to present with multiple symptoms, including altered levels of consciousness or coma, diarrhea, nausea, dyspnea, vomiting, and pain. [2, 3]. Whereas the risk factor for hematological malignancies is increasing age and diabetes mellitus [4].

Hematological cancers significantly affect patients' overall health-related quality of life. Patients often experience considerable financial toxicity, physical distress, and mental health challenges [5-8]. Also, significant number of patients had unmet supportive care needs [9]. 

Hematologic malignancies remained a major global public health issue and the leading cause of global tumor burden, with growing absolute numbers but sharp among several age-standardized measures over the past three decades: especially for non-Hodgkin lymphoma cases showed a continuously increasing trend [10, 11].

Furthermore, the incidence and mortality of leukemia increased. By 2030 globally, the total number of hematological malignancy cases is projected to reach approximately 4,634,937 and account for almost 10% of all cancers diagnosed in sub-Saharan Africa [12-14],

Although the economic burden of HM has increased significantly, by 2050, the burden is expected to shift from high- to middle-income countries [15]. Study indicates that despite being incurable, many patients cases can be successfully managed over many years. So this study is aimed to estimate the pooled burden of bone marrow confirmed malignant hematological disorders. Generating accurate pooled estimates will help inform healthcare planning, resource allocation, and the development of targeted interventions to improve diagnosis, treatment, and long-term care for affected populations.

Objective of the review 

• To estimate pooled prevalence of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter

Study Design and Search Strategy

This study was conducted following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement [16]. The review question prepared using the POCC format: Population: adults, Outcome: prevalence/proportion; Condition: hematologic malignancy and context: Ethiopia and all observational studies. The search strategy utilized in this study used three steps. Firstly, we utilized the advanced PubMed search engine to search for studies using all fields and Medical Subject Headings terms with Boolean operators “OR” and/or “AND”. Subsequently, title, abstract text, and index terms used to describe the articles. Secondly, other databases were searched such as Google Scholar, Scopus, DOAJ, Web of Science, and Google. The search terms used were hematological disorders OR hematological malignancy OR cancer of blood OR blood cancer OR Leukemia OR onco-hematological diseases OR lymphoma OR multiple myeloma OR Myelodysplastic syndromes OR marrow-based malignancies AND adult OR youth OR young AND Ethiopia.  Lastly, the reference lists of all included studies were reviewed to identify any additional studies published in English language up to November 2025. Search limiters like age and language of publication was used.

Eligibility criteria

This study included all observational studies reporting the prevalence bone marrow confirmed malignant hematological disorders among adults without a limitation of study period. Both published and unpublished studies conducted in English were considered. Whereas reviews short reports, and case reports were excluded from these study.

Study extraction and quality appraisal

All authors conducted data extraction using a standardized format in Microsoft Excel 2010. The extracted information included the first author’s name, study year, setting, study design, sample size, and prevalence of hematological malignancy. Screening of studies involves assessing duplication, relevance, full-text accessibility, and alignment with outcomes of interest. Quality assessment was performed using the Newcastle-Ottawa Scale (NOS) [17] by all authors independently. Any discrepancies in quality score of studies between the authors were resolved through discussion. Studies scoring 5 or above on the NOS scale were included for analysis [18].

 Outcome measure

The main objective of this review was to estimate the pooled prevalence of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter.

Data synthesis and analysis

The inverse variance (I2) and Cochran Q statistics was used to evaluate study heterogeneity. I2 test statistics were categorized as low, moderate, and high heterogeneity based on thresholds of 50 %, 50–75 %, and >75 %, respectively [19]. Due to observed heterogeneity, the Dersimonian and Liard random-effects model was applied. Subgroup analysis was conducted to explore potential sources of heterogeneity. Funnel plots and Egger’s test were employed to assess publication bias, with a significance level of 0.05. Additionally, a leave-one-out sensitivity analysis was performed to assess the impact of individual studies on the overall meta-analysis.

Study selection

Initially, 5225 studies were identified through database and manual searches. Of these, 1297 records were excluded due to duplication. The remaining 3928 records undertook title and abstract screening, resulting in the removal of 2987 articles. Nine –hundred and forty one records were sought for retrieval, 279 not retrieved because of they are irrelevant. Six-hundred and sixty-two full-text publications were then assessed for eligibility, with 653 rejected due to, omission of key findings and poor paper quality. At last, 9 studies met the inclusion criteria and were included in the analysis (Figure. 1).

Figure1: PRISMA flow diagram of study selection on prevalence of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter.

Study characteristics

The included studies were retrospective studies [20-28] with 31, 564 participants and mostly conducted in the central region [25–28]. The sample size ranges from 163 [23] to 12671 [27] participants. Among included studies the prevalence of hematological malignancy ranges from 2.8[26]- 17.2 % [24].  All studies had good methodological quality (Table 1).

Table 1: Characteristics of the included studies in the systematic review and meta-analysis.

Prevalence of malignant hematological disorders 

The pooled proportion of malignant hematological disorders was found to be 8.47% (95% CI: 5.28-11.65) with a heterogeneity index of 99.2%, with a P-value of less than 0.001 (Figure 2). 

Figure 2: Forest plot showing pooled prevalence of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter in Ethiopia.

Sub-group analysis 

The subgroup analysis was conducted based on region of the studies conducted. The highest prevalence of hematological malignancy is 11.92 % (95% CI: 4.30- 19.54, I2 = 98.2%) was seen in northern region, and the lowest is 5.82 % (95% CI: 1.78.-9.86, I2 = 99.5%) was seen in central region (Figure. 3).

Figure 3: Subgroup analysis of prevalence of bone marrow confirmed malignant hematological disorders in patients with abnormal hematological parameter in Ethiopia by region.

Meta-regression and publication bias

The heterogeneity index value indicated that the studies were quite varied. Therefore, meta-regression was conducted using year of publication and sample size as a covariates. The analysis showed that publication year and sample size didn’t have a significant effect on heterogeneity between studies, with a P- value of 0.455 and 0.448 respectively. Publication bias was assessed using a funnel plot and the Egger regression test with a significance threshold of<0.05.  Statistical evidence of publication bias was not observed. The funnel plot displayed some asymmetry in the distribution, and the Egger test yielded a statistically non-significant result with a coefficient value of 0.305 and P-value of 0.123 (Figure 4).

Figure 4: Funnel plot to test the publication bias in 9 studies with 95% Confidence limits.

Sensitivity analysis 

Sensitivity analysis was performed to determine how various sources of uncertainty contribute to the overall uncertainty among the studies, but the results indicated that uncertainty has an insignificant influence on pooled prevalence (Figure 5).

Figure 5: Sensitivity analysis of pooled prevalence of bone marrow confirmed malignant hematological disorders in Ethiopia for each study being removed one at a time.

Hematologic malignancies have remained a major global public health issue and the leading cause of the global tumor burden with significant demographic and regional differences [29, 30]. In sub-Saharan Africa hematologic cancers account for approximately 10% of the cancer burden, yet mechanisms for diagnosing, treating, and palliating malignant hematologic disorders are inadequate [31].

According to this study the pooled proportion of malignant hematological disorders in Ethiopia was found to be 8.47% (95% CI: 5.28-11.65), which is lower than the pooled African prevalence (27.30%) [32]. this might be explained by the variation in study populations, this study included only adult population whereas The African included of pediatric studies.

However it is slightly higher than a study conducted in India (6.8%) [33] and Iran (7.15%) [34].  This might be due to difference in diagnostic capacity, registry completeness, the number of included studies, the changing epidemiology, and the nature of the study. 

Current evidence shows that there is a lack of nationwide comprehensive cancer registry data, which makes it difficult to precisely quantify the burden of blood cancers across the whole country. So this study was conducted on limited number of articles because of oncologic centers where located in few places of the country.

The highest prevalence of hematological malignancy is 11.92 %( 95% CI: 4.30- 19.54) was seen in northern region, and the lowest is 5.82 %( 95% CI: 1.78.-9.86) was seen in central region.  This discrepancy may be explained by differences in healthcare infrastructure. The central region had well-established oncologic centers with advanced diagnostic facilities, treatment, and specialized professionals. Furthermore differences in lifestyle factors such as smoking, alcohol use and the burden of infections associated with hematologic cancers such as EBV, HIV, or hepatitis viruses might be reason for discrepancy. 

According to these findings the pooled prevalence of malignant hematological disorders substantial in Ethiopia. Also, the findings highlight marked geographic disparities, which may reflect differences in diagnostic capacity, healthcare access, population characteristics, or underlying risk factors. Strengthening hematologic diagnostic and treatment services and improving cancer registry coverage are essential to ensure earlier detection and better management of hematologic malignancies across the country.

Strength and limitation of the study

This systematic review and meta-analysis provided groundbreaking insights into prevalence of hematological malignancy in Ethiopia. However, there are certain limitations to be considered. The lack of limited studies from most regions of the country may impact the generalizability of the findings. 

Ethics approval and consent to participant

Not applicable

Consent for publication

Not applicable

Availability of data and materials

All the data analyzed during the current systematic review and meta-analysis is fully available with request from corresponding author.

Competing interests

all the authors declare that they have no competing interests

Funding

Not applicable.

Acknowledgment

We would like to thank all authors of studies included in this systematic review and meta-analysis.