Usage Guidelines Please refer to usage guidelines at http://researchonline.lshtm.ac.uk/policies.html or alternatively contact researchonline@lshtm.ac.uk.Available under license: http://creativecommons.org/licenses/by/2.5/ 229Available online http://breast-cancer-research.com/content/6/6/229 IntroductionCancer of the breast in women is a major health burden worldwide. It is the most common cause of cancer among women in both high-resource and low-resource settings, and is responsible for over one million of the estimated 10 million neoplasms diagnosed worldwide each year in both sexes [1]. It is also the primary cause of cancer death among women globally, responsible for about 375,000 deaths in the year 2000 [1].International comparisons of disease rates by area and time of diagnosis can provide important clues to the underlying causes of diseases and the effects of natural or planned interventions, and serve as indicators of the scope for preventive strategies. There is at least a 10-fold variation in breast cancer incidence rates worldwide [2], largely as a consequence of a range of socio-economically correlated differences in the population prevalence of several reproductive, hormonal and nutritional factors. In some high-resource countries, mammographic screening has considerably affected breast cancer diagnosis, registration and mortality.Studies of migrants provided the first solid evidence that environmental (rather than genetic) determinants were responsible for most of the observed international and inter-ethnic differences in breast cancer incidence: comparisons of breast cancer risk in (low-risk) Asian populations migrating to the (high-risk) USA and their offspring revealed major increases in risk between successive generations [3], and increases in risk were observed in populations from European countries with relatively low incidence (Italy and Poland) after migration to Australia, particularly if the migration took place in childhood [4,5].As a consequence of changing exposures to reproductive and nutrition-related determinants over time, women are at increasingly high risk of breast cancer, with incidence rates increasing in most countries and regions of the world in the past few decades. The most rapid rises are seen in developing countries, where breast cancer risk has historically been low relative to industrialised countries. Increasing trends in developing areas are often considered the result of the 'westernisation' of lifestyles, an ill-defined surrogate for changes in factors such as childbearing, dietary habits and exposure to exogenous oestrogen, towards a distribution closer in profile to that of women in industrialised countries.The variations in mortality reflect, in part, variations in incidence (and its determinants), but mortality is also ReviewThe changing global patterns of female breast cancer incidence and mortality AbstractOne 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 ...

BackgroundThe aim was to collate all myasthenia gravis (MG) epidemiological studies including AChR MG and MuSK MG specific studies. To synthesize data on incidence rate (IR), prevalence rate (PR) and mortality rate (MR) of the condition and investigate the influence of environmental and technical factors on any trends or variation observed.MethodsStudies were identified using multiple sources and meta-analysis performed to calculate pooled estimates for IR, PR and MR.Results55 studies performed between 1950 and 2007 were included, representing 1.7 billion population-years. For All MG estimated pooled IR (eIR): 5.3 per million person-years (C.I.:4.4, 6.1), range: 1.7 to 21.3; estimated pooled PR: 77.7 per million persons (C.I.:64.0, 94.3), range 15 to 179; MR range 0.1 to 0.9 per millions person-years. AChR MG eIR: 7.3 (C.I.:5.5, 7.8), range: 4.3 to 18.0; MuSK MG IR range: 0.1 to 0.32. However marked variation persisted between populations studied with similar methodology and in similar areas.ConclusionsWe report marked variation in observed frequencies of MG. We show evidence of increasing frequency of MG with year of study and improved study quality. This probably reflects improved case ascertainment. But other factors must also influence disease onset resulting in the observed variation in IR across geographically and genetically similar populations.

Despite there being sufficient evidence for the effectiveness of screening by cytology in preventing cancer of the cervix uteri, screening policies vary widely among European countries, and incidence is increasing in younger women. This study analyzes trends in squamous cell carcinoma (SCC) of the cervix uteri in 13 European countries to evaluate effectiveness of screening against a background of changing risk. Age-period-cohort models were fitted and period and cohort effects were estimated; these were considered as primarily indicative of screening interventions and changing etiology, respectively. A unique set of estimates was derived by fixing age slopes to one of several plausible age curves under the assumption that the relation between age and cervical cancer incidence is biologically determined. There were period-specific declines in cervical SCC in several countries, with the largest decreases seen in northern Europe. A pattern emerged across Europe of escalating risk in successive generations born after 1930. In the western European countries, a decrease followed by a stabilization of risk by cohort was accompanied by period-specific declines. In southern Europe, stable period, but increasing cohort trends, were observed. Substantial changes have occurred in cervical SCC incidence in Europe and well-organized screening programs have been highly effective in reducing the incidence of cervical SCC. Screening and changing sexual mores largely explain the changing period-and cohort-specific patterns, respectively. The increasing risk in recent cohorts is of obvious concern particularly in countries where no screening programs are in place. Further investigation of the effectiveness of opportunistic screening is warranted as is the observation of differing risk patterns in young cohorts in countries with relatively similar societal structures. (Cancer Epidemiol Biomarkers Prev 2005;14(3):677 -86)

Thyroid cancer incidence rates have increased steadily in the United States and elsewhere. Radiation exposure at a young age is a strong risk factor, but otherwise the etiology is unclear. To explore etiologic clues, we studied the risk of thyroid cancer after an earlier primary cancer, as well as the risk of developing multiple primaries after an earlier thyroid cancer in the U.S. Surveillance, Epidemiology and End-Results (SEER) cancer registries program . In 2,036,597 patients diagnosed with any invasive cancer who survived for a minimum of 2 months, we observed a 42% increased risk compared to the general population for second thyroid cancer based on 1,366 cases (95% confidence interval (CI) 5 35-50%; excess absolute risk (EAR) 5 0.38/ 10,000 person-years (PY)). Elevated risks were observed after most cancer sites studied. The most pronounced excess (observed/ expected (O/E) 5 2.86) was seen for second thyroid cancers detected in the year after diagnosis of the first cancer. Among 29,456 2-month thyroid cancer survivors, 2,214 second cancers occurred (O/E 5 1.11, 95% CI 5 1.06-1.15; EAR 5 7.64/10,000 PY). Again, the highest risk was seen in the first year (O/E 5 1.26). Patients <40 years of age at diagnosis of thyroid cancer had a 39% increased risk of a second cancer, whereas for older patients the risk was elevated 6%. We observed consistently increased risks for cancers of the breast, prostate, and kidney, and a likely radiation treatment-related excess of leukemia. Based on small numbers of cases, cancers of the salivary glands, trachea, scrotum, adrenal glands, and brain and central nervous system (CNS) also occurred in excess. A decreased risk was observed for smoking-related malignancies. Thyroid cancer is associated with primary cancers of many different organs. Although enhanced medical surveillance likely plays a role, 2-way, positive associations between thyroid cancer and cancers of the breast, prostate, kidney, salivary glands, brain and CNS, scrotum, and leukemia suggest etiologic similarities and possible treatment effects. ' 2005 Wiley-Liss, Inc.Key words: multiple primary cancers; thyroid cancer; epidemiology; radiotherapy Approximately 1.5% of new cancers diagnosed in the United States in 2001 were malignancies of the thyroid gland. While the incidence rates are low, they have been increasing over recent decades in many areas of the world. 1 In the United States, about 90% of thyroid cancers are papillary or follicular adenocarcinoma, while anaplastic and medullary cancers account for less than 5% each. 2 The 10-year relative survival rate for thyroid cancer is close to 95%, 3 although the prognosis for anaplastic thyroid cancer is dismal, with few patients surviving beyond 1 year. 4 The demographic characteristics of thyroid malignancies are different from most other cancers. There is a 1:3 male-female ratio and an unusual age distribution. 1 Unlike other malignancies, female thyroid cancer rates increase steeply from the mid-teens until age 50, i.e., around menopause, and steadily decreas...