Showing papers by "Donald Maxwell Parkin published in 2013"

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

Abstract: 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.

Association between smoking and mortality: Khon Kaen cohort study, Thailand.

Abstract: Background: Despite anti-smoking campaigns, smoking prevalence among Thai males aged 30 or older is high, at around 50%. The purpose of this study was to determine the relationship between smoking and mortality in a rural Thai community. Materials and Methods: Subjects enrolled into the Khon Kaen cohort study between 1990 and 2001 were followed up for their vital status until 16 th March 2012. The death resource was from the Bureau of Policy and Strategy, Ministry of Interior, Thailand. A Cox proportional hazards model was used to analyse the association between smoking and death, controlling for age, education level and alcohol drinking, and confidence intervals were calculated using the floating risk method. Results: The study recruited 5,962 male subjects, of whom 1,396 died during a median 13.5 years of follow-up. Current smokers were more likely to die than never smokers after controlling for age, education level and alcohol drinking (HR, 95%CI: 1.41, 1.321.51), and the excess mortality was greatest for lung cancer (HR, 95%CI: 3.51, 2.65-4.66). However, there was no increased risk with increasing dose of tobacco, and no difference in risk between smokers of yamuan (handrolled cigarettes) and manufactured tobacco. Conclusion: Mortality from cancer, particularly lung cancer, and from all causes combined is dependent on smoking status among men in rural Thailand, but the relative risks are lower than have been reported from studies in high income countries, where the tobacco epidemic is more established.

Factors affecting survival time of cholangiocarcinoma patients: a prospective study in Northeast Thailand.

Abstract: Cholangiocarcinoma (CCA) is a major health problem and cause of death among people in Northeastern Thailand. In this prospective study 171 patients newly diagnosed with CCA by physicians in 5 tertiary hospitals in four provinces of northeastern of Thailand between February and July 2011 were followed up to January 2012. The outcome was survival time from diagnosis to death. A total of 758.4 person-months of follow-up were available. The mortality rate was 16.9 per 100 person-months (95%CI: 14.1-20.1). The median survival time among CCA patients was 4.3 months (95%CI: 3.3-5.1). Cox’s proportional hazard model was used to study the independent effects of factors affecting survival time among patients. Statistically significant factors included advanced stage at diagnosis (HR: 2.5, 95%CI: 1.7-3.8), presentation with jaundice (HR: 1.7, 95%CI: 1.1-2.4) or ascites (HR: 2.8, 95%CI: 1.8-4.4), and positive serum carcinoembryonic antigen (HR: 2.3, 95%CI: 1.2-4.3). Patients who had received standard treatment had a better prognosis that those who did not (HR: 0.5, 95%CI: 0.3-0.7). Keywords:

Reply to 'comment on cancer incidence in the United Kingdom: projections to the year 2030'.

Abstract: Sir, We would like to thank Oliver et al (2013) for bringing to our attention these data issues. After careful checking, it is clear that the main source of discrepancy is the difference between the numbers of cancer registrations for 2004–2007, as available in 2010, and the updated numbers released in 2011. Whereas we were aware that there can be substantial delays in registration of some cancers, we had assumed that any changes made after the data are first published would be trivial at a population level and would not affect the analysis of trends over time. Unfortunately, we were wrong. Our projections for leukemia, in particular, are likely to have substantially underestimated the future burden of the disease. Consider the numbers of all cancers (excluding non-melanoma skin cancer) in 2004 in England; according to the MB1 no. 35 (released: 19 December 2006), there were 233 621 cancer cases, but updated statistics released in 2011 recorded 241 700 cases – an increase of 3.3%. The change is particularly great for leukemia (ICD-10: C91–C95; 10.5%) and myeloma (C90; 8.8%). In Table 1, we show how the age-standardised rates of leukemia for each year between 2005 and 2009 has increased in successive data releases. The increase in rates as the data matures will severely distort recent trends and will attenuate projections downwards. Table 1 Age-standardised rates (per 100 000 person years) for leukaemia (C91–95) in England as estimated in successive annual data releases Statistical methods for predicting the eventual number of registrations for each of the last few years deserve a separate investigation, but any approach will need to take into account the changing methodology used in cancer registration, as that will have lead to more timely registration of many tumours. We urge the Office for National Statistics to consider publishing estimated ‘complete registration' data using, for instance, the method adopted by the Surveillance, Epidemiology and End Results (Midthune et al, 2005), who published both unadjusted and delay-adjusted rates (National Cancer Institute, 2012). Here we simply note that the issue is present for virtually all cancer sites to a greater or lesser extent, but appears to be independent of sex and age for any given site (Table 2). Table 2 Change in cancer registrations for 2004 (England) between 2006 and 2011 We have analysed the most recently released data and made projections to 2030 using all data up to 2009, and also limited the analysis to data between 1975 and 2005. The resulting fits for leukemia are shown in Figure 1, together with our previously published results based on the data from the 2010 release for 1975–2007. It is seen that the old data yield particularly optimistic projections, but by including the most recent 4 years of the new data the projections are more optimistic than when these data are excluded. We have also projected all cancers (excluding non-melanoma skin cancer) other than prostate cancer in men and all cancers other than breast cancer in women, treating them as a single site. The reason for the exclusion of prostate and breast cancer is that their incidence has been hugely affected by PSA testing and screening mammography so that the age-period cohort model does not provide a reasonable fit. Our projections based on the 2010 data are very similar to those using the 2011 data for 1975–2005, but are somewhat lower than those that include data for 2006–2009 (Figure 1). The projections using data only up to 2005 are more than 10% lower than those including data for 2006–2007, and projections including data up to 2009 are about 5% greater still (even without adjusting for late registration bias). Figure 1 Observed and projected rates of cancers in Great Britain based on three different data sets. (A) Leukaemia (male). (B) Leukaemia (female). (C) All non-prostate male cancers. (D) All non-breast female cancers. Rates per 100 000 are age-standardised ... Table 3 summarises the effect of using different data sets on age-standardised projections for 2030 for leukaemia, non-Hodgkin lymphoma, myeloma, and for all non-prostate male cancers and non-breast female cancers. The increase in projected rates for 2030, although not quite as great as obtained by Oliver et al (2013), is substantial (about 11% for non-Hodgkin lymphoma and 20–25% for leukemia and myeloma). The projected rates for all non-prostate and non-breast cancers for 2030 are about 9% greater using the new data than they are using the old data (in both cases for 1975–2007). Table 3 Projected (European) age-standardised rates (per 100 000) for 2030 of haematological cancers based on various data sets In summary, late registrations, particularly of haematological cancers, have a profound effect on observed trends in cancer incidence and should be taken into account when projecting future rates.