Tristan Roué

Cervical cancer incidence in French Guiana: South American.

Abstract For the first time, the incidence of cervical cancer was estimated in French Guiana, an overseas French Territory of South America. A certified cancer registry collected exhaustive data on cervical cancer between 2003 and 2005. The age-standardized rate of invasive cervical cancer was 30.3 per 100,000 women. Women from rural areas had lesions with a significantly greater extension than women from urban areas. Compared to South American figures, the standardized incidence of cervical cancer seemed relatively high when viewed in comparison with the gross domestic product per capita. The curative orientation of the health system should move from opportunistic screening for cervical cancer to organized screening, with an emphasis on the rural parts of French Guiana.

Exposition à la scanographie dans l’enfance et risque de cancer à long terme. Une synthèse des études épidémiologiques récentes

Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses.

Survival of patients with invasive cervical cancer in French Guiana, 2003–2008

a Centre D’investigation Clinique, Epidemiologie Clinique Antilles Guyane (Inserm/DGOS CIE802), Centre Hospitalier Andrée Rosemon, Cayenne, France b Registre des Cancers de Guyane, Cayenne, France c Laboratoire d’anatomopathologie, Centre Hospitalier Andrée Rosemon, Cayenne, France d Association Guyanaise de dépistage organisé des cancers, Cayenne, France e Equipe d’accueil EPAT, EA 3593, Université Antilles Guyane, Cayenne, France

SynthèseExposition à la scanographie dans l’enfance et risque de cancer à long terme. Une synthèse des études épidémiologiques récentesExposure to CT scans in childhood and long-term cancer risk: A review of epidemiological studies

Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses.

Predictive Factors of the Survival of Women With Invasive Breast Cancer in French Guiana: The Burden of Health Inequalities.

BACKGROUND The prognosis of patients with breast cancer in French Guiana is worse than in France, with 23 deaths per 100 incident cases versus 17 per 100 in metropolitan France. This study aimed to compare the relative survival of patients with invasive breast cancer (IBC) between women from French Guiana and metropolitan France and to determine risk factors influencing breast cancer survival in French Guiana. MATERIALS AND METHODS Data were collected from the Cancer Registry of French Guiana. We compared the relative survival of women with IBC between French Guiana and metropolitan France. We used the Cox proportional hazard regression to evaluate the effect of prognostic factors on cancer-specific mortality in French Guiana. RESULTS We included all 269 cases of IBC in women diagnosed in French Guiana between 2003 and 2009. The overall 5-year relative survival rate of patients with IBC was 79% in French Guiana and 86% in metropolitan France. The place of birth (foreign country vs. French territory), the tumor stage at the time of diagnosis, the mode of diagnosis (symptoms vs. screening), the presence of hormone receptors in the tumor, and the histologic type were the variables associated with survival differences. None of the other study variables were significantly associated with prognosis. CONCLUSION Access to care for migrants is challenging, which leads to health inequalities. Early detection through prevention programs is crucial to increase IBC survival, notably for foreign-born patients.

The Spectrum of Infectious Disease-Related Cancers

Despite the epidemiologic transition shifting the burden from infectious diseases to chronic noncommunicable diseases, infections still remain a huge cause of morbidity and mortality in much of the tropical world. When considering all infectious causes of cancer together, they amount to the second most frequent cause of cancer, after tobacco. In sub-Saharan Africa, infections cause one third of all cancers. Viruses remain the cause of nearly three quarters of infection-related cancers. Three viruses, human papillomaviruses and hepatitis B and C viruses, represent 85 % of virus-related cancers. The bacterium H. pylori, however, causes a quarter of the burden of all infection-related cancers. Given the numerical importance of these cancers and their preventability, efforts must be sustained to roll back the burden of infection-related cancers. In developing countries, up to a quarter of all cancers could be avoided by controlling these infections.

Epidemiology of Cancer in the Tropical Areas

More than 40 % of the world population resides in the tropics. The tropics encompass the countries between the Tropic of Cancer in the Northern Hemisphere and the Tropic of Capricorn in the Southern Hemisphere. Incidence and mortality are estimated from the GLOBOCAN database. Many specific causes of cancer are now known in the tropics, the most important being smoking, obesity, hormonal factors, and a few oncogenic viruses. Much of the incidence and mortality disparity between developed and developing countries in the tropics are the result of differences in distribution of these factors. Most cancers are in principle preventable or avoided by a suitable choice of lifestyle and environment. The socioeconomic transition in many tropical countries leads to a reduction in infection-related cancers to cancers associated with risk factors that are mainly noninfectious.

Screening for cervical cancer in French Guiana: screening rates from 2006 to 2011

In French Guiana, the age-standardized incidence rate of cervical cancer is four times higher than in France and the mortality rate 5.5 times higher. A survival study revealed that stage at diagnosis was the main factor influencing the prognosis, showing that early detection is crucial to increase cervical cancer survival. The present study aimed at evaluating the cervical cancer screening rate between 2006 and 2011 by age and for a 3-year period in French Guiana. All pap smears realised in French Guiana were analysed in two laboratories allowing exhaustive review of screening data. The screening rate was estimated at about 54% from 2006 to 2011, with a statistical difference between coastal and rural area (56.3% versus 18.7%). Although the methodological difference did not allow comparisons with metropolitan France, these results could be used to evaluate the impact of organised cervical cancer screening by the French Guiana Association for Organized Screening of Cancers which has been implemented in French Guiana since 2012.RésuméEn Guyane, l’incidence du cancer du col de l’utérus est quatre fois plus élevée qu’en métropole, et la létalité 5,5 fois plus élevée. Dans ce vaste département recouvert à plus de 90 % de forêt amazonienne, les difficultés d’accès aux soins, l’âge précoce au premier rapport et le manque de dépistage sont de possibles facteurs explicatifs. Une première étude a montré que le diagnostic tardif était le principal facteur impactant la survie. Un diagnostic précoce - par frottis cervico-vaginal tous les 3 ans de 25 à 64 ans selon les recommandations nationales - est donc crucial pour améliorer la survie. L’objectif de cette étude est d’évaluer le taux de couverture de dépistage par frottis en Guyane entre 2006 et 2011 ainsi que l’activité de réalisation de frottis et le taux de cancers dépistés. Tous les frottis cervico-vaginaux réalisés en Guyane sont analysés dans seulement deux laboratoires d’anatomie pathologique, ce qui permet une analyse exhaustive des données de dépistage de ce département. La date de naissance, la date de réalisation du frottis, l’adresse de la patiente ou celle du prescripteur (selon les laboratoires) ainsi que la date de réalisation du précédent frottis ont été recueillis. Le taux de couverture de dépistage a été évalué à 54 % entre 2006 et 2011, avec une différence significative entre le littoral et l’intérieur de la Guyane (56,3 % versus 18,7 %). L’activité de réalisation de frottis était de 23,5 à 25,8 frottis pour 100 femmes-année. Le taux de diagnostic de cancer était de 191,8/100 000 femmes-année, soit un cancer cervical diagnostiqué pour 521 personnes dépistées. Bien que le taux de couverture de dépistage en Guyane ne semble pas très différent de la métropole, nous ne pouvons réaliser de comparaison statistique du fait de la différence de méthodologie utilisée. Le taux de diagnostic de cancer était de 6 à 12 fois plus élevé qu’en métropole, confirmant l’importance du dépistage par frottis en Guyane. Des efforts de dépistage doivent être réalisés notamment dans l’intérieur de la Guyane, où le taux de dépistage est plus faible. Cet état des lieux du dépistage entre 2006 et 2011 pourra permettre d’évaluer l’impact de la campagne organisée de dépistage du cancer du col mise en place en 2012 par l’Association guyanaise du dépistage organisé des cancers (AGDOC).

The epidemiology of breast cancer in French Guiana 2003–2006

For the first time the incidence and mortality of breast cancer were estimated in French Guiana, an overseas French Territory of South America. A certified cancer registry collected exhaustive data on breast cancer between 2003 and 2005. The age-standardized rate of breast cancer was 47.1 per 100 000 women. The age-standardized death rate was 11.0 per 100 000 women. Although the standardized incidence and death rates were lower than in metropolitan France and South America, the ratio between incidence and mortality showed that the prognosis of breast cancer in French Guiana was worse than in metropolitan France (23 deaths per 100 incident cases versus 17 deaths per 100 incident cases, respectively). The demographics of French Guiana, suggests that mass organized screening may benefit from lowering the age of its target population.

Cancer Screening and Prevention in the Tropics

Primary cancer prevention and screening for early detection in resource-limited tropical areas should be focused toward cancers causing the greatest burden of disease. This burden is partly due to population growth and aging and to slow progress against infection-related cancers and the marketing-driven rise of smoking and obesity. The predicted demographic changes will probably increase the number of people with cancer to more than 20 million per year by 2030. However, the implementation of preventive measures targeting known risk factors in low- and middle-HDI countries could be highly effective and could avert much of the predicted rise of incidence and mortality. These interventions include smoking reduction, promotion of physical activity and healthy eating, and vaccinations against hepatitis B virus and carcinogenic human papillomavirus infections. Early detection of cervical cancer and, where possible, breast and colon cancer will also contribute to the reduction of cancer mortality.