Distribution and trends of cancer in Buffalo City, Eastern Cape Province, 1991-2009: a retrospective study

Abstract

Despite interventions, cancer remains a global public health concern. Cancer burden continues to grow globally, demanding the implementation of important preventative and control initiatives. Informative reports on existing routine cancer data are therefore required. This study describes the distribution and trends of cancer in Buffalo City (BFC) population, Eastern Cape (EC) Province for the period 1991-2009. Cancer patients were retrospectively surveyed in the database of Frere Hospital Oncology-Radiation Unit. Proportion by sex, race, geographical distribution in the province and top cancer sites were calculated. Direct method of standardisation was used to calculate Age Standardised Rates (ASR) for a subpopulation of patients residing at BFC; age-specific rates were applied to the reference population (World Standard Population). Trends in rates with 95% Confidence Intervals (CI) for two most common cancers in males and females over time adjusted for age and sex and interactions between time and race were assessed using Poisson Regression. A total of 19 737 patients´ records were analysed; 38.8% (7 656) males and 61.2% (12 081) females. Most patients were Black Africans (81.5%), followed by Whites (13.5%), Mixed Race (4.5%) and Asians (0.5%). A larger proportion (46.0%) of the patients were from Buffalo City, while the rest were distributed in other municipalities served by Frere Hospital. Top five cancers in males were lung [22.5%, ASR 21.0], prostate [14.7%, ASR 9.2], larynx [5.8%,ASR 5.0], mouth [4.4%, ASR 3.7] and tongue [3.8%, ASR 2.9 per 100 000] in females; cervix [20.9%, ASR 23.0], breast [23.6%, ASR 20.2], lung [3.4%, ASR 4.7], ovary [2.1%, ASR 3.0] and corpus uteri [3.4%, ASR 2.8]. Trends showed a decrease in lung and prostate cancers in males, while cervix and breast remained stable in females. White males were two times (95% CI: 1.87-2.49) more likely to have lung cancer and five times (95% CI: 3.90-6.21) more likely to have prostate cancer than Black Africans. White females were 0.43 (95% CI: 0.44-0.73) less likely to have cervical cancer and three times (95% CI: 2.45-3.14) more likely to have breast compared to Black Africans. In conclusion, the availability of routine cancer data at Frere Hospital contributes to strengthening of the national cancer notification regulation, as the results of this study suggest that the burden of cancer in the EC Province remains high.