Age Specific Incidence of Breast Cancer in Calabar, Nigeria

Aim: To determine the incidence of breast cancer in our uncharted population with a view to determining the disease burden so as to aid planning and intervention.

Study Design: A trend analysis of breast cancers in Calabar between 1st January 2004 to 31st December 2013.

Place and Duration of Study: Calabar Cancer Registry, May to June 2015.

Methodology: Data obtained from record of registered cases of breast cancer seen within 2004 to 2013 from Calabar registry area, was entered and analyzed using SPSS version 21.0. The information sought for includes sex of patients, age, place domiciled in the last one year, rural or urban dwelling as well as topography and morphology of the breast cancers. The population of females domiciled in Calabar was determined using the 2006 national population census data and 3.0 % population growth as specified by the national population commission.

Results: Three hundred and sixty nine cases of breast cancers, comprising 11 males and 358 females were seen during this period. Male breast cancer cases were excluded from further analysis. The mean (SD) age of female cases was 44.9 (11.9) years, ranging from 23 to 85 years. Approximately half of the cases (176 or 49.2%) were seen in the 34 to 50 years age group with commonest age group at diagnosis being 40 - 44 years age group. There was a fairly steady increase in annual frequency of cases seen within study period, with 2011 yielding the highest proportion of cases (54 or 14.5%), and about two-thirds of cases (227 or 63.4%) were seen in the latter half of the 10-year study period. Adjusted incidence rate was highest in 2010 (61.3 per 100,000), and high incidence rates was found among subjects in 65-69 year age group in 2009 (179 per 100,000), and 55-59 year age group in 2010 (192 per 100,000).The age specific incidence rate of breast cancer in Calabar is 37.4 per 100,000.

Conclusion: This study has shown that breast cancer is common in Calabar, and it occurs at a relatively early age.