Trends in the incidence of cancer in the black population of Harare, Zimbabwe 1991-2010.

Incidence rates of different cancers have been calculated for the black population of Harare, Zimbabwe for a 20-year period (1991-2010) coinciding with continuing social and lifestyle changes, and the peak, and subsequent wane, of the HIV-AIDS epidemic. The overall risk of cancer increased during the period in both sexes, with rates of cervix and prostate cancers showing particularly dramatic increases (3.3% and 6.4% annually, respectively). By 2004, prostate cancer had become the most common cancer of men. The incidence of cancer of the esophagus, formerly the most common cancer of men, has remained relatively constant, whereas rates of breast and cervix cancers, the most common malignancies of women, have shown significant increases (4.9% and 3.3% annually, respectively). The incidence of Kaposi sarcoma increased to a maximum around 1998-2000 and then declined in all age groups, and in both sexes The incidence of squamous cell cancers of the conjunctiva is relatively high, with temporal trends similar to those of Kaposi sarcoma. Non-Hodgkin lymphoma, the fifth most common cancer of men and fourth of women, showed a steady increase in incidence throughout the period (6.7-6.9% annually), although rates in young adults (15-39) have decreased since 2001. Cancer control in Zimbabwe, as elsewhere in sub-Saharan Africa, involves meeting the challenge of emerging cancers associated with westernization of lifestyles (large bowel, breast and prostate), while the incidence of cancers associated with poverty and infection (liver, cervix and esophagus) shows little decline, and the residual burden of the AIDS-associated cancers remains significant.

Cancer survival in Harare, Zimbabwe, 1993-1997.

The Zimbabwe national cancer registry was established in 1985 as a population-based cancer registry covering Harare city. Cancer is not a notifiable disease, and registration of cases is done by active methods. The registry contributed data on randomly drawn sub-samples of Harare resident cases among 17 common cancer sites or types registered during 1993-1997 from black and white populations. Follow-up was carried out predominantly by active methods with median follow-up ranging from 1-54 months for different cancers. The proportion with histologically verified diagnosis for various cancers ranged from 20-100%; death certificate only (DCO) cases comprised 0-34%; 58-97% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 94-100%. Five-year age-standardized relative survival rates of selected cancers among both races combined were cervix (42%), breast (68%), Kaposi sarcoma (4%), liver (3%), oesophagus (12%), stomach (20%) and lung (14%). Survival was markedly higher among white than black populations for most cancers with adequate cases. Five-year relative survival by age group was fluctuating, with no definite pattern or trend.

A historical perspective of registered cases of malignant ocular tumors in Zimbabwe (1990 to 1999). Is HIV infection a factor?

INTRODUCTION: Anecdotal and published reports suggest that ocular tumours are on the increase in Zimbabwe. OBJECTIVES: To determine the trends in incidence rates of common malignant ocular tumours registered with the Zimbabwe Cancer Registry during the last decade (1990 to 1999). DESIGN: Retrospective study. SETTING: Data were collected from the Zimbabwe National Cancer Registry, the Zimbabwe National Census 1992 and 2002 Reports, and patient records from hospitals. SUBJECTS: All cases of malignant ocular tumours registered with the Zimbabwe National Cancer Registry between 1 January 1990 and 31 December 1999. MAIN OUTCOME MEASURES: Age standardized annual incidence rates for registered cases of common ocular tumours. RESULTS: The age-adjusted annual incidence rates of squamous cell carcinoma of the conjunctiva had a more than 10-fold increase from 0.17 to 1.8 per 100,000 people during periods 1990 and 1999 respectively. Retinoblastoma dropped by more than half from 0.8 to 0.34 per 100,000 during the same period. The annual age standardised incidence rates for all ocular tumours showed a significant upward linear trend (chi2: 362.78, df=9 and p < 0.001). There was no significant gender difference in the distribution of these tumours amongst the study population. CONCLUSION: The increasing trend in the age-adjusted annual incidence rates of ocular surface squamous neoplasms could be attributed to the worsening HIV and AIDS pandemic in Zimbabwe or improved access/utilization of health services by the public.

Calculating age-adjusted cancer survival estimates when age-specific data are sparse: an empirical evaluation of various methods.

We evaluated empirically the performance of various methods of calculating age-adjusted survival estimates when age-specific data are sparse. We have illustrated that a recently proposed alternative method of age adjustment involving the use of balanced age groups or age truncation may be useful for enhancing calculability and reliability of adjusted survival estimates.

Cancer incidence in the African population of Harare, Zimbabwe: second results from the cancer registry 1993-1995.

The data of the population-based cancer registry in Harare, Zimbabwe, for 1993-1995 are presented and compared with those from 1990-1992. The most significant change in rates is the striking increase in the incidence of Kaposi's sarcoma (KS) in both men and women, compatible with the evolution of the AIDS epidemic in sub-Saharan Africa. The incidence of KS doubled in both sexes and now accounts for 31.1% of registered cancers. It has overtaken breast cancer to become the second most common tumour in African women, after cervical cancer, and is now one of the leading childhood tumours, accounting for 10. 3% of cancers recorded in children (ages 0-14). With the exception of KS, the incidence and pattern of occurrence of the other malignant neoplasms changed little during the observed 6 years.

Aids and cancer in Africa: the evolving epidemic in Zimbabwe.

BACKGROUND: Zimbabwe is severely affected by the AIDS epidemic, and many cancers in African populations are related to infectious agents. OBJECTIVE: To study the current pattern, and short-term changes in incidence, of cancers related to infectious agents (and especially to HIV), with respect to the evolving epidemic of AIDS. METHODS: Analysis of data on the African population of Harare, Zimbabwe, from the Zimbabwe Cancer Registry, for the period 1990-1995. Comparison with data on prevalence of HIV seropositivity, and notifications of AIDS. RESULTS: Comparing results from 1993-1995 with those for 1990-1992 shows a continuing increase in the incidence of Kaposi's sarcoma with a doubling of the rates in both men and women. A dramatic increase in the incidence of squamous cell tumours of the conjunctiva was also observed, as well as a significant increase in the incidence of non-Hodgkin's lymphoma in women. There was no apparent increase in risk for Hodgkin's disease, myeloma, liver cancer, or cancer of the cervix. CONCLUSIONS: The AIDS epidemic has had a dramatic effect on the profile of cancer. The changes in incidence involve several cancers previously linked to AIDS in North America and Europe.

Cancer of the skin in Zimbabwe: an analysis based on the Cancer Registry 1986 to 1992.

OBJECTIVES: To determine whether skin cancers are increasing. DESIGN: Cancer Registry series. SETTING: Cancer Registry Office in Harare, Zimbabwe. This registry serves the referral hospitals in Harare and Bulawayo. SUBJECTS: All cancer patients (9,029 males, 8,730 females) notified from 1986 to 1992. MAIN OUTCOME MEASURE: Proportion of skin cancer to the total cancers notified. RESULTS: The limitations of the Cancer Registry were noted. In Black Zimbabweans, skin cancers increased from 381 (11% of all notifications) in 1986 to 1,346 (29.7% of all notifications) in 1992. The increase was due to an increase in Kaposi's sarcoma in both men and women although the number notified in women was a quarter of that notified in men. In White Zimbabweans, there was a significant increase in basal cell carcinoma in men and this cancer increased with age from 6.52 per 1,000 population in people 30 to 54 years to 25.04 per 1,000 in those over 54 years of age. CONCLUSION: Our findings show that the number of people with skin cancers is on the increase probably due to the AIDS epidemic and also the aging of the White population, with implications for the demand for health care for treating these cancers in a health service working on a very tight budget.

Cancer in the European population of Harare, Zimbabwe, 1990-1992.

The data presented from the population-based cancer registry in Harare, Zimbabwe, represent the first information on the incidence of cancer in a population of European origin living in Southern Africa for over 30 years. Their cancer pattern is more or less typical of white populations of high socio-economic status living in Europe or North America, with elevated incidence rates of breast cancer, large-bowel cancer and, in women, lung cancer. However, there are also several unusual features, with extremely high incidence rates of skin cancers, including melanomas, and higher rates of liver and bladder cancer than normally seen in white populations.

Cancer in the African population of Harare, Zimbabwe, 1990-1992.

The data presented from the population-based cancer registry in Harare, Zimbabwe, represent the first information on the incidence of cancer in Southern Africa for almost 20 years. In the African population in Zimbabwe there are several features in common with other countries in sub-Saharan Africa: high rates of liver, prostate and cervix cancer, low rates of large-bowel cancer and breast cancer. Also, as reported from southern and south-eastern Africa, there are relatively high incidence rates of cancers of the oesophagus, bladder and (in men) lung. The AIDS epidemic has given rise to a striking increase in incidence of Kaposi's sarcoma (now the commonest cancer of African men), but there is not much evidence for an increase in incidence of non-Hodgkin lymphomas nor, although rates are very high, of cervical cancer.

Zimbabwe National Cancer Registry: summary data 1986-1989. National Cancer Registry Advisory Committee.

The Zimbabwe National Cancer Registry began operation in 1986. Between 1986-1989, a total of 8 276 cases were identified. Among men of African descent, oesophageal (11.2 pc) and liver cancer (11.0 pc) were most common. Cervical cancer was by far the most common among women of African descent (34.5 pc). Among both males and females of non-African descent, skin cancers (other than melanoma) accounted for one-third of cancers followed by prostate cancer (7.7 pc) in males and breast cancer (18.5 pc) in females. These findings are comparable to earlier reports of the epidemiology of cancer in Zimbabwe.