The study population consisted of any patient who had consulted the Anoalite Hospital in Mungbere, precisely its gynecology department, during the period of our study.

The sample size was calculated using Epi Info CDC 7.5.2.0 software. We referred to the prevalence of 17.7% found in Mexico, which gave us a minimum sample size of 217 cases. We used exhaustive sampling. Thus, all patients followed up with a histologically proven diagnosis of breast cancer and who had a complete medical record, that is, containing all the variables included in this study, were included in the study.

Non-inclusion criteria:

Data collection was retrospective based on documentary technique. The consultation sheet, patient file, laboratory register, analysis vouchers and results of histopathology and immunohistochemistry examination, ultrasound registers, surgical protocol registers and follow-up sheets were consulted for data collection.

As a data collection tool, we used a previously established data collection sheet.

This data collection tool was validated by the management team of the Gynecology-Obstetrics Department of the University Clinics of Kisangani, but also by the ethics committee of the Haut-Uélé province.

The following parameters are contained in the data collection sheet: sociodemographic characteristics, patient history, data relating to breastfeeding and last pregnancy, clinical, paraclinical, therapeutic and anatomopathological aspects of breast cancer.

Data entry was carried out using Microsoft Office 365 Excel 2024 software in order to create a database that could be analyzed with specialized software. For data analysis, we used Epi-Info CDC version 7.5.2.0 software. For qualitative variables, we calculated the numbers and their percentages, while quantitative variables were grouped into classes (slices) in order to determine the numbers and their percentages.

This work was conducted in strict compliance with the principles of the Declaration of Helsinki, namely the protection of the dignity, autonomy, privacy and confidentiality of patients. We also obtained approval from the Research Ethics Committee of the University of Uélé bearing the number UNIUELE/CER/405/2024.

Table 1 shows us that the age group between 61 and 70 years predominates with 65 cases out of 217, or 30%. Regarding marital status, we observe that single women are the most affected with 146 cases or 67.3%. As for the profession, the majority of patients were unemployed with 145 cases or 66.8%.

It appears from Table 2 that most of the patients came from Isiro with 60 cases, or 27.6%.

From the analysis of Table 3 , it emerges that 178 cases out of 217 or 82.0% had BI-RADS 5; while the abnormality of glucose tolerance was observed in 3.2% of patients.

Reading Table 4 shows that invasive cancer was the most observed in our series with 85.3% of patients; among whom 94.1% were carriers of the ductal type. On the other hand, among the 14.7% of patients who were carriers of in situ cancer, 53.1% had the ductal type. The majority of our respondents had grade III SBR with 91.7%; 94.0% were positive for estrogen receptors. The results of our study found that all patients had HER2 overexpressed status > 30%. Finally, all of our subjects had Ki 67 ≥ 20%.

The results of our study show that the age group between 61 and 70 years predominates with 65 cases out of 217, or 30%.

These results corroborate those reported in South Africa where the mean age at diagnosis of patients followed for breast cancer was 54.4 years [11] .

Furthermore, Motolouze et al. [12] found that the age of patients varied between 20 and 84 years with a mean age of 48.27 ± 12.44 years. The most represented age group in their study was that ranging from 40 to 49 years (29.5%).

Kemfang Ngowa et al. [13] found a mean age of 47.5 years.

Several African studies on breast cancer report varied demographic trends. For example, a Moroccan study by Elidrissi et al. [14] in 2016 had identified a peak in incidence between 45 and 54 years, contrary to our trends (61 - 70 years, 30%).

Regarding marital status, we observe that single women are the most affected with 146 cases or 67.3%. A Nigerian study conducted by Ibrahim et al. [15] in 2018 noted a predominance of married women (58%), which is different from our observation characterized by the predominance of single women (67.3%).

We believe that this divergence may be linked to distinct socio-cultural contexts.

The predominance of single women in our study could be explained by the fact that they never had the chance to breastfeed. Indeed, according to the literature, it is recognized that breastfeeding is a protective factor against breast cancer for women. In addition to the aforementioned explanation, the strong predominance of single women could be explained by the socio-cultural contexts of our environment essentially characterized by mining activities with regard to the regions of origin of patients. Indeed, in most mining areas of our region, the majority of women are single, thus exposed to nulliparity and/or pauciparity, explaining a vicious circle of factors associated with the occurrence of breast cancer.

Regarding the profession, Senegalese work by Ly et al. [16] in 2019 highlighted a high rate of patients with a profession with 61% of cases, contrary to our results which found 66.8% unemployed, reflecting regional economic disparities.

Regarding breast ultrasound, 178 out of 217 cases or 82.0% had BI-RADS 5; while pre-intervention glucose tolerance abnormality was observed in 3.2% of patients.

The results of our study corroborate those obtained by other studies in the literature, such as Mphahlele et al. [17] , in their South African study conducted in 2019, had highlighted that breast imaging remains a crucial tool for early diagnosis in an environment where resources remain limited, with a marked predominance of high BI RADS classifications, a finding that joins our 82% of BIRADS 5 found during our study, indicating a high suspicion of malignancy and a delay in screening, particularly in regions where high-quality mammography is difficult to access.

Along the same lines, Azim et al. [18] analyzed in 2023, in the Egyptian context, that the absence of systematic screening and regular follow-up inevitably leads to late presentation, with large tumors.

Furthermore, Dada et al. [19] , in a Nigerian radiological study published in 2020, highlighted the importance of breast ultrasound and BI-RADS classification in the early detection of suspicious lesions, with a significant proportion of patients classified as BIRADS 5, which directly corroborates our results of 82% and demonstrates that, despite technical and financial limitations, imaging remains an essential tool to guide therapeutic management in contexts where access to more advanced modalities remains limited.

Finally, our result regarding glucose intolerance observed in 3.2% of patients is similar to that obtained by Okeke et al. [20] , in their 2021 study on glucose tolerance in women with breast cancer in Nigeria who identified an association between abnormalities in carbohydrate metabolism and certain tumor profiles, a finding which, despite its low prevalence (3.2% in our series), opens up avenues for reflection on the possible interaction between metabolic status and tumor progression.

These findings highlight the urgency of improving accessibility to screening services, strengthening the training of health professionals and setting up awareness programs adapted to local realities, in order to enable early detection and optimal therapeutic management, elements which, according to our findings and those of the authors cited above, could significantly contribute to reducing the morbidity and mortality linked to this pathology.

The use of ultrasound for breast cancer staging in our environment is explained by the deficit of our technical platform. In addition, in most cases, this ultrasound examination is initiated for the purpose of diagnostic orientation. Even if the examination of choice is mammography, our health structure uses the means at its disposal.

The results of our study show that invasive cancer was the most observed in our series with 85.3% of patients; among whom 94.1% were carriers of the ductal type. On the other hand, among the 14.7% of patients who were carriers of in situ cancer, 53.1% had the ductal type. The majority of our respondents had grade III of SBR with 91.7%; 94.0% were positive for estrogen receptors and all patients had HER 2 overexpressed status > 30%. Finally, all of our subjects had the percentage of Ki 67 ≥ 20%.

These results corroborate those obtained by other authors in the literature. Indeed, Newman [21] had already highlighted in his 2017 study that, in several regions of Africa, the absence of effective screening programs and delays in access to care largely contribute to the predominance of infiltrating cancers, a finding that is in perfect resonance with our 85.3% of cases of infiltrating carcinoma.

Furthermore, the Ivorian study by Koffi et al. [22] conducted in 2015 reported a high frequency of infiltrating cancers, highlighting the fact that ductal carcinoma remains the most frequent subtype, although the exact percentages may differ slightly due to variations in histopathological classification and differences in interpretation between laboratories, which corroborates our observation of 94.1% of ductal cancers among infiltrating cancers.

As for the results regarding hormone receptor positivity, a study conducted in Egypt in 2023 by Azim et al. [18] reported that the expression of hormone receptors, particularly estrogen receptors, was extremely high, with percentages close to those we observed (94.0%), and also noted that HER 2 overexpression was a marker of poor prognosis, often associated with intense proliferative activity, illustrated by a high Ki 67, which is consistent with our results where all patients present had a Ki 67 ≥ 20% and HER 2 overexpression greater than 30%.

Along similar lines, Mbunda et al. [23] in their 2018 Zambian analysis found that the epidemiological profile of breast cancer was characterized by a high proportion of invasive cancers with a predominance of ductal carcinoma, and although their study also noted some variability in biomarker expression, particularly for hormone receptors and HER2, their findings align with our results in showing that breast cancers in Africa tend to have aggressive biological features, including high proliferative activity as measured by high Ki 67.

Furthermore, Diarra et al. [24] , during their study conducted in Mali in 2022, had a predominance of patients presenting at stage 4 of breast cancer progression, which corroborates with most African studies conducted on this pathology.

The high predominance of patients with HER 2 overexpression > 30 could be explained by the fact that in our environment, most patients come after a transfer from health facilities more or less distant from our study environment, many of them arrive at a very advanced and/or terminal stage of the pathology. The infrastructural constraints of the environment characterized by the deterioration of road infrastructure, the totally rudimentary technical platforms of neighboring structures, and the financial constraints of the population are among many other obstacles that explain the delay in histopathological diagnosis and management of patients in our sample.