Current trends in bladder cancer in England and Wales.

PURPOSE: We examined trends in bladder cancer (BC) incidence, mortality and survival in England and Wales during a 30-year period. MATERIALS AND METHODS: Age standardized incidence and mortality rates for BC, cohort incidence ratios, and 1 and 5-year relative survival from BC were calculated, and current trends were assessed. RESULTS: Between 1971 and 1998 the total number of cases of BC increased by 57% from around 7,200 to almost 11,400. Between 1971 and 1998 directly age standardized incidence increased by 16% in males and 37% in females. Directly age standardized mortality decreased by 26% in males and showed little change in females during the same period. Five-year relative survival improved by around 15% points in the 1970s and early 1980s. However, there was less improvement in survival thereafter in that 5-year relative survival for patients diagnosed in 1993 to 1995 was 67% in men and 58% in women. CONCLUSIONS: With an almost 60% increased incidence during the last 3 decades, BC incidence remains much higher in men but has increased more rapidly in women. There have been steady decreases in mortality rates, more marked in men than in women. Unusually, women have a significantly lower survival rate than men. Reasons for these patterns and trends are unclear. The trends in bladder cancer incidence by birth cohort suggest that the relationship with smoking may not be that strong and that other factors may be involved. Further research should focus on reasons for the recent increase in bladder cancer incidence in younger female birth cohorts.

Outcomes of screening to prevent cancer: analysis of cumulative incidence of cervical abnormality and modelling of cases and deaths prevented.

OBJECTIVE: To determine the frequency of different outcomes in women participating in cervical screening. DESIGN: Analysis of screening records from 348 419 women, and modelling of cases of cervical cancer and deaths with and without screening. SETTING: Cervical screening programme in Bristol. RESULTS: For every 10 000 women screened from 1976 to 1996, 1564 had abnormal cytology, 818 were investigated, and 543 had abnormal histology. One hundred and seventy six had persistent abnormality for two years or more. In the absence of screening 80 women would be expected to develop cancer of the cervix by 2011, of whom 25 would die. With screening 10 of these deaths would be avoided. Comparison of cumulative abnormality rates with numbers expected to develop cancer in the absence of screening suggests that at least 80% of high grade dyskaryosis and of high grade dysplasia would not progress to cancer. The lifetime risk of having abnormal cytology detected could be as high as 40% for women born since 1960. CONCLUSIONS: Screening is labour and resource intensive. It involves treatment for many women not destined to develop invasive cancer. The increased intervention rate for cervical abnormality in England is due to change in practice, not a cohort effect, and is probably the reason for the marked fall in incidence and mortality during the 1990s. For other cancers there is scope for major iatrogenic harm from screening because of invasive tests and treatments.

Effect of NHS breast screening programme on mortality from breast cancer in England and Wales, 1990-8: comparison of observed with predicted mortality.

OBJECTIVE: To assess the impact of the NHS breast screening programme on mortality from breast cancer in women aged 55-69 years over the period 1990-8. DESIGN: Age cohort model with data for 1971-89 used to predict mortality for 1990-8 with assumption of no major effect from screening or improvements in treatment until after 1989. Effect of screening and other factors on mortality estimated by comparing three year moving averages of observed mortality with those predicted (by five year age groups from 50-54 to 75-79), the effect of screening being restricted to certain age groups. SETTING: England and Wales. SUBJECTS: Women aged 40 to 79 years. RESULTS: Compared with predicted mortality in the absence of screening or other effects the total reduction in mortality from breast cancer in 1998 in women aged 55-69 was estimated as 21.3%. Direct effect of screening was estimated as 6.4% (range of estimates from 5.4-11.8%). Effect of all other factors (improved treatment with tamoxifen and chemotherapy, and earlier presentation outside the screening programme) was estimated as 14.9% (range 12.2-14.9%). CONCLUSIONS: By 1998 both screening and other factors, including improvements in treatment, had resulted in substantial reductions in mortality from breast cancer. Many deaths in the 1990s will be of women diagnosed in the 1980s and early 1990s, before invitation to screening. Further major effects from screening and treatment are expected, which together with cohort effects should result in further substantial reductions in mortality from breast cancer, particularly for women aged 55-69, over the next 10 years.