Mónica S. Sierra

Global patterns and trends in colorectal cancer incidence and mortality

Objective The global burden of colorectal cancer (CRC) is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In this study, we aim to describe the recent CRC incidence and mortality patterns and trends linking the findings to the prospects of reducing the burden through cancer prevention and care. Design Estimates of sex-specific CRC incidence and mortality rates in 2012 were extracted from the GLOBOCAN database. Temporal patterns were assessed for 37 countries using data from Cancer Incidence in Five Continents (CI5) volumes I–X and the WHO mortality database. Trends were assessed via the annual percentage change using joinpoint regression and discussed in relation to human development levels. Results CRC incidence and mortality rates vary up to 10-fold worldwide, with distinct gradients across human development levels, pointing towards widening disparities and an increasing burden in countries in transition. Generally, CRC incidence and mortality rates are still rising rapidly in many low-income and middle-income countries; stabilising or decreasing trends tend to be seen in highly developed countries where rates remain among the highest in the world. Conclusions Patterns and trends in CRC incidence and mortality correlate with present human development levels and their incremental changes might reflect the adoption of more western lifestyles. Targeted resource-dependent interventions, including primary prevention in low-income, supplemented with early detection in high-income settings, are needed to reduce the number of patients with CRC in future decades.

Effect of Helicobacter pylori Infection on Growth Velocity of School-age Andean Children

Background: Helicobacter pylori infection affects about half of the worlds population and is usually acquired in childhood. The infection has been associated with chronic gastritis, peptic ulcer, and stomach cancer in adulthood. Little is known, however, about its consequences on child health. We examined the effect of H. pylori infection on growth among school-age children in the Colombian Andes by comparing growth velocity in the presence and absence of H. pylori infection. Methods: Children who were 4–8 years old in 2004 were followed up in a community where infected children received anti-H. pylori treatment (n = 165) and a comparison community (n = 161) for a mean of 2.5 years. Anthropometry measurements were made every 3 months and H. pylori status ascertained by urea breath test every 6 months. Growth velocities (cm/month) were compared across person-time with and without infection, using mixed models for repeated measures. Results: In the untreated community, 83% were H. pylori-positive at baseline and 89% were -positive at study end. The corresponding prevalences were 74% and 46%, respectively, in the treated community. Growth velocity in the pretreatment interval was 0.44 (standard deviation [SD] = 0.13) cm/month. Models that adjusted for age, sex, and height estimated that H. pylori-positive children grew on average 0.022 cm/month (95% confidence interval = 0.008 to 0.035) slower than H. pylori-negative children, a result that was not appreciably altered by adjustment for socioenvironmental covariates. Conclusions: This study suggests that chronic H. pylori infection is accompanied by slowed growth in school-age Andean children.

Stomach cancer burden in Central and South America

RATIONALE AND OBJECTIVE Stomach cancer mortality rates in Central and South America (CSA) are among the highest in the world. We describe the current burden of stomach cancer in CSA. METHODS We obtained regional and national-level cancer incidence data from 48 population-based registries (13 countries) and nation-wide cancer deaths from WHOs mortality database (18 countries). We estimated world population age-standardized incidence (ASR) and mortality (ASMR) rates per 100,000 and estimated annual percent change to describe time trends. RESULTS Stomach cancer was among the 5 most frequently diagnosed cancers and a leading cause of cancer mortality. Between CSA countries, incidence varied by 6-fold and mortality by 5-6-fold. Males had up to 3-times higher rates than females. From 2003 to 2007, the highest ASRs were in Chile, Costa Rica, Colombia, Ecuador, Brazil and Peru (males: 19.2-29.1, females: 9.7-15.1). The highest ASMRs were in Chilean, Costa Rican, Colombian and Guatemalan males (17.4-24.6) and in Guatemalan, Ecuadorian and Peruvian females (10.5-17.1). From 1997 to 2008, incidence declined by 4% per year in Brazil, Chile and Costa Rica; mortality declined by 3-4% in Costa Rica and Chile. 60-96% of all the cancer cases were unspecified in relation to gastric sub-site but, among those specified, non-cardia cancers occurred 2-13-times more frequently than cardia cancers. CONCLUSION The variation in rates may reflect differences in the prevalence of Helicobacter pylori infection and other risk factors. High mortality may additionally reflect deficiencies in healthcare access. The high proportion of unspecified cases calls for improving cancer registration processes.

Prostate cancer burden in Central and South America

RATIONALE AND OBJECTIVE The incidence of prostate cancer has increased in Central and South America (CSA) in the last few decades. We describe the geographical patterns and trends of prostate cancer in CSA. METHODS We obtained regional and national-level cancer incidence data from 48 population-based registries in 13 countries and nation-wide cancer deaths from the WHO mortality database for 18 countries. We estimated world population age-standardized incidence (ASR) and mortality (ASMR) rates per 100,000 person-years for 2003-2007 and the estimated annual percent change (EAPC) to describe time trends. RESULTS Prostate cancer was the most common cancer diagnosis and one of the leading causes of cancer deaths among males in most CSA countries. From 2003-2007, ASRs varied between countries (6-fold) and within countries (Brazil: 3-6-fold). French Guyana (147.1) and Brazil (91.4) had the highest ASRs whereas Mexico (28.9) and Cuba (24.3) had the lowest. ASMRs varied by 4-fold. Belize, Uruguay and Cuba (24.1-28.9) had the highest ASMRs while Peru, Nicaragua, and El Salvador (6.8-9.7) had the lowest. In Argentina, Brazil, Chile and Costa Rica prostate cancer incidence increased by 2.8-4.8% annually whereas mortality remained stable between 1997 and 2008. CONCLUSION The geographic and temporal variation of prostate cancer rates observed in CSA may in part reflect differences in diagnostic and registration practices, healthcare access, treatment and death certification, and public awareness. The incidence of prostate cancer is expected to increase given recent early detection activities and increased public awareness; however, the impact of these factors on mortality remains to be elucidated.

Cervical cancer in Central and South America: Burden of disease and status of disease control

RATIONALE AND OBJECTIVE More than 20 years after cytology-based screening was introduced in Central and South America (CSA), cervical cancer remains a leading cause of cancer incidence and mortality in the region. Although several population-based registries exist in the region, few comprehensive analyses have been conducted to describe the status of cervical cancer control. METHODS Population-based data from cancer registries in 13 countries and mortality data from 18 countries in CSA were analyzed. Standardized incidence and mortality rates were estimated and time trend analysis performed when information was available. In addition, a search of available data on HPV vaccination and cervical cancer screening was carried out. RESULTS Cervical cancer incidence and mortality have decreased in some CSA countries, with an annual percentage change from -4.2 to -6.7 for incidence and -0.2 to -8.3 for mortality. In total, seven countries have age-standardized mortality rates over 10 per 100,000 women, generally corresponding to those with the lowest income levels. All countries have implemented screening programs with different extents of coverage and levels of organization. To date, nine countries have introduced HPV vaccination in national immunization programs. CONCLUSIONS Despite incidence declines observed in some countries, cervical cancer mortality remained almost stable in most countries in the region. Decreases in mortality trends in Chile and Costa Rica are probably the result of early detection programs. Better organized programs might favor greater impact on cancer incidence and mortality, but technological developments offer more suitable opportunities for prevention and alternative approaches for screening of precancerous lesions.

Burden of colorectal cancer in Central and South America

RATIONALE AND OBJECTIVE The colorectal cancer (CRC) burden is increasing in Central and South American due to an ongoing transition towards higher levels of human development. We describe the burden of CRC in the region and review the current status of disease control. METHODS We obtained regional- and national-level incidence data from 48 population-based cancer registries in 13 countries, as well as cancer deaths from the WHO mortality database for 18 countries. We estimated world population age-standardized incidence (ASR) and mortality (ASMR) rates per 100,000 person-years for 2003-2007 and the estimated annual percentage change for 1997-2008. RESULTS The CRC rate in males was 1-2 times higher than that in females. In 2003-2007, the highest ASRs were seen in Uruguayan, Brazilian and Argentinean males (25.2-34.2) and Uruguayan and Brazilian females (21.5-24.7), while El Salvador had the lowest ASR in both sexes (males: 1.5, females: 1.3). ASMRs were<10 for both sexes, except in Uruguay, Cuba and Argentina (10.0-17.7 and 11.3-12.0). CRC incidence is increasing in Chilean males. Most countries have national screening guidelines. Uruguay and Argentina have implemented national screening programs. CONCLUSION Geographic variation in CRC and sex gaps may be explained by differences in the prevalence of obesity, physical inactivity, diet, smoking and alcohol consumption, early detection, and cancer registration practices. Establishing optimal CRC screening programs is challenging due to lack of healthcare access and coverage, funding, regional differences and inadequate infrastructure, and may not be feasible. Given the current status of CRC in the region, data generated by population-based cancer registries is crucial for cancer control planning.

Cancer patterns and trends in Central and South America

RATIONALE AND OBJECTIVE Cancer burden is increasing in Central and South America (CSA). We describe the current burden of cancer in CSA. METHODS We obtained regional and national-level cancer incidence data from 48 population-based registries (13 countries) and nation-wide cancer mortality data from the WHO (18 countries). We estimated world population age-standardized incidence and mortality rates per 100,000 person-years. RESULTS The leading cancers diagnosed were prostate, lung, breast, cervix, colorectal, and stomach, which were also the primary causes of cancer mortality. Countries of high/very high human development index (HDI) in the region experienced a high burden of prostate and breast cancer while medium HDI countries had a high burden of stomach and cervical cancers. Between countries, incidence and mortality from all cancers combined varied by 2-3-fold. French Guyana, Brazil, Uruguay, and Argentina had the highest incidence of all cancers while Uruguay, Cuba, Argentina, and Chile had the highest mortality. Incidence of colorectum, prostate and thyroid cancers increased in Argentina, Brazil, Chile and Costa Rica from 1997 to 2008, while lung, stomach and cervical cancers decreased. CONCLUSION CSA carries a double-burden of cancer, with elevated rates of infection- and lifestyle-related cancers. Encountered variation in cancer rates between countries may reflect differences in registration practices, healthcare access, and public awareness. Resource-dependent interventions to prevent, early diagnose, and treat cancer remain an urgent priority. There is an overwhelming need to improve the quality and coverage of cancer registration to guide and evaluate future cancer control policies and programs.

The burden of cutaneous melanoma and status of preventive measures in Central and South America

RATIONALE AND OBJECTIVE Very little is known about the burden of cutaneous melanoma in Central and South America, despite the existence of a reasonable amount of population-based data. We present data on melanoma incidence calculated in a standardized way for Central and South America, as well as an overview of primary and secondary prevention issues in the region. METHODS Cancer registry data on all incident cases reported in the different registries present in Central and South America were combined to provide registry-based country estimates of age-standardized, sex-specific cutaneous melanoma incidence overall, and by histological subtype and anatomical site. A literature search provided additional information. RESULTS Age-standardized incidence rates were between 1 and 5 per 100,000 and tended to be higher further away from the equator. Cutaneous melanomas of the acral type, mostly occurring on the lower limbs, are a distinguishing feature of melanoma in Central and South America in comparison with high-incidence areas. Several preventive measures, both primary and secondary, are in place, albeit largely without evaluation. CONCLUSION Due to incomplete registration and different registration practices, reliable and comparable data on melanoma were difficult to obtain; thus it is likely that the true burden of melanoma in Central and South America has been underestimated. The different characteristics of the cutaneous melanoma patient population in terms of anatomical site and histological type distribution imply a need for adapted primary and secondary prevention measures. The generally high ambient ultraviolet radiation levels require sufficient sun protection measures.

Descriptive epidemiology of lung cancer and current status of tobacco control measures in Central and South America

RATIONALE AND OBJECTIVE Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death in the world. In Central and South America lung cancer is now one of most frequent cancers and the leading cause of cancer-related death in both sexes. We describe patterns and trends in lung cancer incidence and mortality in Central and South America and give a brief overview of the current status of tobacco control measures based on the most recent MPOWER report. METHODS We obtained regional and national-level incidence data from 48 population-based cancer registries in 13 countries and cancer deaths from the WHO mortality database for 18 countries. We estimated world population age-standardized incidence and mortality rates per 100,000 person-years. Incidence of lung cancer by histological subtype were only available from high-quality population-based cancer registries for the period 2003-2007. RESULTS The highest incidence and mortality rates in the region were seen among males in Argentina, Cuba, Chile and Uruguay. Adenocarcinoma was the most frequent histological type overall, though squamous carcinoma was more frequent in Antofagasta-Chile and Villa Clara-Cuba. Smoke-free policies and warnings are widely implemented tobacco control measures; cessation is offered but the costs are not covered by health systems in the majority of countries. CONCLUSION The high burden of lung cancer in the region highlights the need to improve long term information and strengthen current tobacco control policies including aggressive taxing measures and supporting smoking cessation in order to achieve the targeted reductions in smoking prevalence.

What do we know about benefits of H. pylori treatment in childhood

Policy analysis shows that H. pylori test and treat strategies targeting adults at moderate to high risk of H. pylori-induced disease is likely to be cost-effective for preventing digestive diseases responsible for a large global disease burden. Little is known, however, about health benefits to children from eliminating this infection. We conducted a systematic review of the evidence regarding health benefits to children from treatment to eliminate H. pylori infection. We systematically searched Ovid MEDLINE for pertinent review articles published through 2012. We excluded reviews focused on treatment efficacy and scrutinized reference lists of selected reviews to identify additional eligible reviews. Fifteen reviews met specified inclusion criteria. Overall, they show that few reported studies investigating pediatric health effects of treatment for H. pylori infection were well designed with adequate statistical power. Thus, there is insufficient evidence for drawing conclusions about health benefits to children from treatment to eliminate H. pylori infection.