Breast cancer trends differ by ethnicity: a report from the South African National Cancer Registry (1994-2009)

Abstract

Background: To describe breast cancer (BC) incidence and mortality by ethnicity in South Africa (SA).

Methods: Sources of data included the South African National Cancer Registry (NCR) pathology-based reports (1994–2009) and Statistics South Africa (SSA) mortality data (1997–2009). Numbers of cases, age-standardised incidence rates (ASIR) and lifetime risk (LR) were extracted from the NCR database for 1994–2009. Age-specific incidence rates were calculated for five-year age categories. The direct method of standardisation was employed to calculate age-standardised mortality rates (ASMR) using mortality data.

Results: Between 1994 and 2009, there were 85 561 female BC. For the Black, Coloured and Asian groups, increases in ASIR and LR were observed between 1994 and 2009. In 2009, the ASIR for the total population, Blacks, Whites, Coloureds and Asians were 26.9, 18.7, 50.2, 40.9 and 51.2 per 100 000, respectively. For Asians, an increase in proportion of BC as a percentage of all female cancers was observed between 1994 and 2002 (11.1%) and continued to increase to 2009 (a further 4.5%). Whites and Asians presented higher incidences of BC at earlier ages compared with Blacks and Coloureds in 2009. In 1998, there were 1618 BC deaths in SA compared with 2784 deaths in 2009. ASMR between 1997 and 2004 increased but stabilised thereafter.

Conclusion: This paper demonstrated that SA BC incidence rates are similar to other countries in the region, but lower than other countries with similar health systems. Ethnic differences in BC trends were observed. However, the reasons for observed ethnic differences are unclear.