Breast cancer is the leading cause of cancer-related death in women in both developed and developing countries [1] . In sub-Saharan Africa, it comes in second place after cervical cancer [2] . In Cameroon, the WHO classified breast cancer as the first cancer in women with a prevalence of 35.1% followed by cervical cancer (14.9%) [3] [4] . The diagnosis of breast cancer involves several paraclinical investigations including medical imaging and histopathology [5] . The combination of mammography and ultrasound has a high sensitivity in the detection of malignant breast pathologies [6] . The results of these explorations are usually presented in a standardised classification to ensure uniformity of interpretation and imaging reports: the Breast Imaging-Reporting and Data System (BIRADS) of the American College of Radiology (ACR). This classification, in category 3 (BIRADS-3) includes probably benign lesions which need a short-term imaging follow-up. According to the guidelines, the predictive value of malignancy in this category is between 0% and 2% [7] .

In Africa, some studies conducted in Burkina Faso, Gabon and Cameroon have shown a higher frequency of malignancies in this category than that described in the guidelines with values ranging from 3.5% to 13% [5] [8] [9] [10] . A south-Korean study reported in 2014 showed that 40% of occult cancers in this category were detected at the second check-up [11] . Assessing cancer occurrence in BIRADS-3 lesions could be important to a better management approach, especially in our specific setting where medical imaging programs are not subsidised and where patients have to support themselves the financial costs induced by their follow-up. Indeed, the lesions graded BIRADS-3 remain insufficiently evaluated during imaging check-ups in our context. We therefore carried out this study to assess the cancer occurrence and associated factors in BIRADS-3 lesions during the follow-up in order to propose an adaptation of the management for this category in our setting.

In this retrospective longitudinal study, we aimed to assess the cancer occurrence and associated factors in BIRADS-3 lesions during the follow-up in order to propose a justified adaptation of the management for this category in our setting. Our results demonstrated that the global frequency of cancers among initial BIRADS-3 lesions reached 10.9%, imaging follow-up compliance is 23.9% and malignancies were more associated to age above 40 and nipple discharge.

The mean age of our study population, was 33.0 ± 13.4 years with extremes of 13 and 73 years, 68.1% of patients being under 40 years, making our sample a predominantly young population. These results are similar to that found in Nigeria in 2018 [12] on the management of BIRADS-3 breast lesions where the mean age was 29.7 years (13 - 68 years) and the most represented age group was 20 - 29 years. Ndé-Ouedraogo et al in Burkina-Faso in 2018 [5] reported a mean age of 38.2 years. But some European and Asian series [7] [13] [14] found higher average ages ranging from 41 to 59.6 years. The method of recruitment in our series from symptomatic patients could explain why our patients are younger. Indeed, at least 91.1% of our patients were symptomatic, with palpable breast mass or nodule, breast pain or nipple discharge whereas in the above referenced studies, inclusion was done from voluntary screenings which are generally the prerogative of women above 40 years. Concerning risk factors of breast cancer, hormonal contraception was found in 26.3% and family history of cancer in 12.4% but without any correlation with malignancy, contrary to what is described in the literature [15] . This could be explained by the youth of our study population.

According to the recommendations, BIRADS-3 lesions must be monitored clinically and radiologically at 4 to 6 months, and then at 12 and 24 months [12] [13] [14] . During this monitoring, if the lesion progresses to BIRADS-4, a histopathology evidence is necessary. As stated in the ancillary analysis paper early reported [16] , the participation to imaging controls was low and decreasing over time. A more aggressive strategy was then advocated such as a telephone reminder system or an iterative biopsy as credible alternative to the low compliance with imaging follow-up. Our global compliance was 23.9% and the number of lesions upgraded to BIRADS-4 reached 29.1% with 10.9% of overall initial BIRADS-3 being malignant, 61.0% of lesions being stable. This occurrence of cancer was mainly correlated with the age above 40 and to the presence of nipple discharge. Studies done in the United States [17] [18] found 3% of cancers during the follow-up of BIRADS-3 lesions. In South-Korea in 2016, 80.6% of initial BIRADS-3 lesions were stable and only 1.0% were found to be malignant at 1 year or more [14] . In Spain in 2001, only 1% of lesions were reclassified as BIRADS-4 [19] . All these studies found a positive predictive value of malignancy in concordance with the literature. The high incidence of malignancy in our series may be explained by a poor imaging follow-up due to low financial income and then lower compliance with controls than those in the studies above. In our setting, would it not be preferable to consider an upgrade to BIRADS-4 at the term of the first control if the lesion is not reclassified as BIRADS-2 so that histopathological samples can be collected? A similar recommendation was proposed in others african studies [5] [10] .

The global frequency of malignancies among initial BIRADS-3 lesions in this series, of 10.9%, is higher than that described in the international guidelines. This study highlights the need to be more proactive in the management of BIRADS-3 lesions in our setting as the compliance with follow-up is low. So, upgrading to BIRADS-4 in order to perform biopsy should be considered as an alternative to long-term follow-up for patients above 40, non reclassified as BIRADS-2, non-compliant with the first imaging check-up and presenting with nipple discharge. The proposed adaptation of the management approach might ensure an earlier diagnosis of breast malignancy for better patient outcomes.

The authors declare no conflicts of interest regarding the publication of this paper.

Nwatsock, J.-F., Seme-Engoumou, A.M., Mendouga-Menye, C.R.B., Atenguena-Okobalemba, E., Tabola, L. and Moifo, B. (2023) Cancer Occurrence and Associated Factors to Malignancy in BIRADS-3 Lesions in Yaoundé: The Need to Be More Proactive for Patients above 40, Non-Compliant with Imaging Follow-Up and Presenting with Nipple Discharge. Open Journal of Medical Imaging, 13, 127-135. https://doi.org/10.4236/ojmi.2023.134013