Recent trends in breast cancer incidence in Sweden

A global view on cancer incidence and national levels of the human development index

Socioeconomic factors are associated with cancer incidence through complex and variable pathways. We assessed cancer incidence for all cancers combined and 27 major types according to national human development levels. Using GLOBOCAN data for 184 countries, age-standardized incidence rates (ASRs) were assessed by four levels (low, medium, high, very high) of the Human Development Index (HDI), a composite index of life expectancy, education, and gross national income. A strong positive relationship between overall cancer incidence and HDI level was observed. When comparing the ASR in very high HDI regions with that in low HDI regions, we observed a positive association ranging from 2 to 14 and 2 to 11 times higher in males and females, respectively, depending on the cancer type. Positive dose-response relationships between the ASR and HDI level were observed in both sexes for the following cancer types: lung, pancreas, leukemia, gallbladder, colorectum, brain/nervous system, kidney, multiple myeloma, and thyroid. Positive associations were also observed for testicular, bladder, lip/oral cavity, and other pharyngeal cancers, Hodgkin lymphoma, and melanoma of the skin in males, and corpus uteri, breast, and ovarian cancers and non-Hodgkin lymphoma in females. A negative dose-response relationship was observed for cervical and other pharyngeal cancers and Kaposi sarcoma in females. Although the relationship between incidence and the HDI remained when assessed at the country-specific level, variations in risk within HDI levels were also observed. We highlight positive and negative associations between incidence and human development for most cancers, which will aid the planning of cancer control priorities among countries undergoing human development transitions.

Effects of acupuncture, applied relaxation, estrogens and placebo on hot flushes in postmenopausal women: an analysis of two prospective, parallel, randomized studies

OBJECTIVE

To assess if transdermal or oral estrogens, acupuncture and applied relaxation decrease the number of menopausal hot flushes/24 h and improve climacteric symptoms, as assessed by the Kupperman index, more than transdermal placebo treatment.

SETTING

An outpatient clinic at a Swedish university hospital.

METHODS

A total of 102 postmenopausal women were recruited to two studies performed in parallel. In Study I, the women were randomized between transdermal placebo or estrogen treatment and, in Study II, between oral estrogens, acupuncture or applied relaxation for 12 weeks. Climacteric symptoms were measured with daily logbooks on hot flushes. Women completed the assessment questionnaire for the Kupperman index at baseline and after 12 weeks.

RESULTS

The number of flushes/24 h decreased significantly after 4 and 12 weeks in all groups except the placebo group. Both at 4 and 12 weeks, acupuncture decreased the number of flushes more (p<0.05; p<0.01, respectively) than placebo. At 12 weeks, applied relaxation decreased the number of flushes more (p<0.05) than placebo. The Kupperman index score decreased in all groups except the placebo group. The decrease in score was significantly greater in all treatment groups than in the placebo group (p<0.01).

CONCLUSION

Acupuncture and applied relaxation both reduced the number of hot flushes significantly better than placebo and should be further evaluated as alternatives to hormone therapy in women with menopausal vasomotor complaints.

Psychological well-being improves in women with breast cancer after treatment with applied relaxation or electro-acupuncture for vasomotor symptom

The aim of this study was to evaluate the effect of applied relaxation and electro-acupuncture (EA) on psychological well-being in breast cancer-treated women with vasomotor symptoms. Thirty-eight breast cancer-treated postmenopausal women with vasomotor symptoms were included in the study. They were randomized to either treatment with electro-acupuncture (EA) (n = 19, three of them with tamoxifen) or applied relaxation (AR) (n = 19, five of them with tamoxifen) over a 12-week study period with six months follow-up. Vasomotor symptoms were registered daily. A visual analog scale was used to assess climacteric symptom, estimation of general well-being was made using the Symptom Checklist, and mood using the Mood Scale. These were applied during treatment and at follow-up. In total 31 women completed 12 weeks of treatment and six months of follow-up. Hot flushes were reduced by more than 50%. Climacteric symptoms significantly decreased during treatment and remained so six months after treatment in both groups. Psychological well-being significantly improved during therapy and at follow-up visits in both groups. Mood improved significantly in the electro-acupuncture treated group. In conclusion psychological well-being improved in women with breast cancer randomized to treatment with either AR or EA for vasomotor symptoms and we therefore suggest that further studies should be performed in order to evaluate and develop these alternative therapies.

Use of statistics to assess the global burden of breast cancer

A variety of statistics are used to quantify the burden (occurrence and outcome) of cancer generally and of breast cancer specifically. When undertaking any cancer control program, understanding these statistics, their source, and their quality is important for assessing the current situation, allocating resources to different control strategies, and evaluating progress. Two core statistics are the cancer incidence rate and the cancer mortality rate, which provide estimates of the average risk of acquiring and of dying from the disease, respectively. About 16% of the world's population is covered by registration systems that produce cancer incidence statistics, while mortality data are available for about 29%. Breast cancer incidence and mortality vary considerably by world region. In general, the incidence is high (greater than 80 per 100,000) in developed regions of the world and low (less than 30 per 100,000), though increasing, in developing regions; the range of mortality rates is much less (approximately 6-23 per 100,000) because of the more favorable survival of breast cancer in (high-incidence) developed regions. The incidence of breast cancer is increasing almost everywhere. This unfavorable trend is due in part to increases in risk factors (decreased childbearing and breast-feeding, increased exogenous hormone exposure, and detrimental dietary and lifestyle changes, including obesity and less physical activity). On the other hand, mortality is now decreasing in many high-risk countries due to a combination of intensified early detection efforts and the introduction of mammographic screening, resulting in the diagnosis of more small, early stage tumors, and advances in treatment.

Breast cancer incidence, mortality and survival in the Umbria region of Italy (1978–1999)

Recent incidence, mortality and survival rates of female invasive breast cancer in the Umbria region were compared with data of 20 years ago and with data from other Italian Registries. Incidence data, derived from an ad hoc survey and from cancer registry records, were analysed for the periods 1978-1982 and 1994-1999; mortality trend rates were calculated based on data from official publications and the variation was assessed by joinpoint analysis. Fifteen-year survival rates, observed, relative and age-adjusted, were also calculated. Compared with the years 1978-1982, the age-adjusted incidence rates rose during 1994-1999, while age-adjusted mortality rates decreased in this latter period. Incidence and mortality rates specific for each age group showed a constant increase with age, in both periods of observation, especially among women from 50 to 75 years of age. The 5-year relative survival rates increased 17%, rising from 0.71 in 1978-1982 to 0.86 in 1994-1998; the survival improvement was evident among women aged 45-54, and 65-74. Age-adjusted incidence and mortality rates in Umbria were lower than in other Italian Registries and survival rates showed a better prognosis for breast cancers diagnosed in Umbria in the period 1994-1998. In conclusion, the 1994-1998 decline in breast cancer mortality and the survival improvement may in part reflect the effectiveness of earlier detection by mammography and the progress in treatments. Genetic and lifestyle factors along with the improvement in diagnosis, and in quality of data collection and classification could have determined the recorded increase in breast cancer incidence.

The changing global patterns of female breast cancer incidence and mortality

One in ten of all new cancers diagnosed worldwide each year is a cancer of the female breast, and it is the most common cancer in women in both developing and developed areas. It is also the principal cause of death from cancer among women globally. We review the descriptive epidemiology of the disease, focusing on some of the key elements of the geographical and temporal variations in incidence and mortality in each world region. The observations are discussed in the context of the numerous aetiological factors, as well as the impact of screening and advances in treatment and disease management in high-resource settings.

Breast cancer mortality trends in two areas of the province of Florence, Italy, where screening programmes started in the 1970s and 1990s

We compared breast cancer mortality rates in the period 1985-2000 in two areas of the province of Florence, Italy, where breast cancer screening programmes started in the 1970s (early screening (ES) area) and in 1990s (late screening (LS) area). The overall age-standardised mortality decreased in the whole period by 40.9% in the ES area (P<0.001), and by 11.3% in the LS area (P=0.030). Significant decreases in the ES area were detected in groups aged 45-54 years (61.1%; P= 0.018) and 65-74 years (44.7%; P= 0.049), whereas in the LS area no significant decrease was detected in any age group. The relatively low compliance in the first years of the programme in both areas, and the long enrollment period in the LS area could have reduced the effect on mortality. Our findings suggest that the drop in mortality in the ES area (41%) could be explained by both service screening and better care. The slight decrease in mortality in the LS area (11%) could be mainly due to better care. A reduction of about 30% is attributable to screening in the ES area over the period 1985-2000.

Breast cancer incidence and mortality trends in 16 European countries

Trends in the incidence of and mortality from breast cancer result from a variety of influences including screening programmes, such as those introduced in several European countries in the late 1980s. Incidence and mortality rates for 16 European countries are analysed. Incidence increased in all countries. The estimated annual percent change (EAPC) varied from 0.8 to 2.8% in prescreening years in 6 'screened' countries and from 1.2 to 3.0% in 10 'non-screened' countries. Screening related temporary increases were visible. Earlier mortality trends were maintained in the most recent decade in Estonia (EAPC +1.8%) and Sweden (-1.2%). In other countries, previously increasing trends changed. Trends flattened in Finland, Denmark, France, Italy and Norway (EAPC 0.0 to -0.3%), while they declined in England and Wales (-3.1%), Scotland (-2.0%), and The Netherlands (-1.0%), all of which have national screening programmes, and in Slovakia (-1.1%), Spain (-0.7%), and Switzerland (-1.1%). In some countries with screening programmes, declines in mortality started before screening was introduced, and declines also occurred in non-screened age groups and in some countries without national screening programmes. This suggests that the major determinants of the observed trends vary among the countries and may include earlier detection through screening in countries where this has been introduced, but also improvements in therapy, in countries with or without screening.

Trends in breast cancer incidence in Hong Kong between 1973 and 1999: an age-period-cohort analysis

Hong Kong has the highest breast cancer incidence in Asia and studying secular changes in its rates may lead to hypotheses regarding disease aetiology and also predictions of future trends for China. We examined statistics from the Hong Kong Cancer Registry based on 26 566 cases of invasive breast cancer from 1973 to 1999. The trends in breast cancer incidence were studied using log-linear longitudinal models. We further analysed the independent effects of chronological age, time period and birth cohort on incidence trends using age-period-cohort modelling. The average annual per cent change of the age-standardised incidence was 3.6% during 1973-1999. Age-period-cohort modelling indicated the incidence development was predominantly a cohort effect, where the rise in relative risk was seemingly linear in successive birth cohorts, showing a 2-3-fold difference when comparing women born in the 1960's with those born around 1900. Our results suggest that direct and indirect consequences of westernisation may have been responsible for most of the observed increase in breast cancer incidence. As China moves towards a more westernised way of life, we can expect an emerging epidemic of breast cancer as Hong Kong's experience has demonstrated.

Trends in breast cancer mortality in Asturias, Spain

While breast cancer mortality rates are subsiding or beginning to decline in many western countries, in Spain they are increasing. We have studied breast cancer mortality rates in Asturias (Spain) by using the age-period-cohort model for the period of 1975-1994. There was an increase in the adjusted rates. The increase of relative risk of death in the period 1990-1994, in relation to that in 1975-1979, was 43%. There is a tendency for successive cohorts to have higher age-specific rates than previous cohorts. Trends in breast cancer mortality rates have been driven predominantly by birth cohort rate trends over the last decades in Asturias, suggesting that the changes in breast cancer mortality have been largely influenced by changes in aetiological factors.

Breast cancer in New South Wales in 1972-1995: tumor size and the impact of mammographic screening

To examine the use of mammographic screening in women in New South Wales (NSW), we measured uptake of initial mammograms and estimated the proportions of breast cancers that were screen detected. To see if mammographic screening has been associated with reductions in advanced breast cancers and mortality from breast cancer, we analyzed trends in age-specific and age-standardized breast cancer incidence and mortality from 1972 to 1995 and tumor size in 1986, 1989, 1992 and April to September 1995. Between 1984 and the end of 1995, an estimated 72% of NSW women in their 50s and 67% in their 60s had had at least 1 mammogram and, in 1995, an estimated 39% of invasive breast cancers in women in these age groups were detected by mammography. Before 1989, breast cancer incidence increased only slightly (+1.3% annually) but then, from 1990 to 1995, increased more rapidly (+3.1% annually). Between 1986 and 1995, rates of small cancers (< 1 cm) increased steeply by 2.7 times in women 40-49 years of age and 5.6 times in women 50-69 years of age. The incidence of large breast cancers (3+ cm), after little apparent change to 1992, fell by 17% in women 40-49 years of age and 20% in those 50-69 years of age to 1995. Breast cancer mortality increased slightly between 1972 and 1989 (+0.5% annually) but then fell (-2.3% annually) from 1990 to 1995. We concluded that breast cancer rates had been influenced in expected directions by the introduction of mammographic screening in women resident in NSW. We expect that recent falls in incidence of larger breast cancers and breast cancer mortality will become steeper as screening coverage increases in the second half of the 1990s.

Breast cancer in Norway 1970-1993: a population-based study on incidence, mortality and survival

The incidence, mortality and survival of breast cancer patients from 1970 to 1993 were studied using data from the Cancer Registry of Norway. The age-adjusted incidence rate increased from 62.0 to 76.9 per 100,000 person-years during the period, and more than 2000 cases are now registered annually. The increase tends to be highest in the age group below 40 years. The increase is mainly found in cases with localized tumours at the time of diagnosis. The mortality rate has been almost unchanged in the period; the age adjusted mortality rate is 27.0 per 100,000 person-years at the end of the study period. The 5-year overall survival has increased among cases with axillary lymph node metastases at the time of diagnosis; the other stages show only little improvement.