Clustering time trends of breast cancer incidence in Africa: a 27-year longitudinal study in 53 countries

Background: Breast cancer is the most common, frequently diagnosed cancer with the highest incidence among female worldwide. Although the incidence is decreasing in developed countries, it is on increase in most of the African countries.
Objective: This study aimed to identify different time trends of breast cancer incidence among African countries using latent mixture approach.
Methods: The information includes newly diagnosed breast cancer patients per 100,000 women for 53 African countries in a period of 1990-2016. Latent mixture modeling was performed in Mplus 7.4 software.
Results: The overall trend of breast cancer in Africa was increasing. Latent mixture model with 5 clusters was estimated as the best using fit indices and linear growth trajectories were specified for each cluster. Nigeria was the only country which belongs to a cluster with negative slope indicating a slow decrease in the breast cancer incidence; also, Seychelles was the only country that showed a sharp increase over time. 31 countries belonged to a cluster with a slope of 0.08, indicating that the incidence of breast cancer is almost constant over time. Cluster 3 including Algeria, Angola, Botswana, Central African Republic, Cote d’lvoire, Equatorial Guinea, Lesotho, Libya, Namibia, Somalia, Sudan, Swaziland, Uganda and Zimbabwe and cluster 2 including Gabon, Mauritius, Morocco, South Africa, Tunisia and Congo showed a slow and moderate increase in the incidence of breast cancer, respectively.
Conclusion: Providing health education programs is essential in African countries with rising trend of breast cancer during the last decades.