Weakly Supervised Learning using Attention gates for colon cancer histopathological image segmentation.

Recently, Artificial Intelligence namely Deep Learning methods have revolutionized a wide range of domains and applications. Besides, Digital Pathology has so far played a major role in the diagnosis and the prognosis of tumors. However, the characteristics of the Whole Slide Images namely the gigapixel size, high resolution and the shortage of richly labeled samples have hindered the efficiency of classical Machine Learning methods. That goes without saying that traditional methods are poor in generalization to different tasks and data contents. Regarding the success of Deep learning when dealing with Large Scale applications, we have resorted to the use of such models for histopathological image segmentation tasks. First, we review and compare the classical UNet and Att-UNet models for colon cancer WSI segmentation in a sparsely annotated data scenario. Then, we introduce novel enhanced models of the Att-UNet where different schemes are proposed for the skip connections and spatial attention gates positions in the network. In fact, spatial attention gates assist the training process and enable the model to avoid irrelevant feature learning. Alternating the presence of such modules namely in our Alter-AttUNet model adds robustness and ensures better image segmentation results. In order to cope with the lack of richly annotated data in our AiCOLO colon cancer dataset, we suggest the use of a multi-step training strategy that also deals with the WSI sparse annotations and unbalanced class issues. All proposed methods outperform state-of-the-art approaches but Alter-AttUNet generates the best compromise between accurate results and light network. The model achieves 95.88% accuracy with our sparse AiCOLO colon cancer datasets. Finally, to evaluate and validate our proposed architectures we resort to publicly available WSI data: the NCT-CRC-HE-100K, the CRC-5000 and the Warwick colon cancer histopathological dataset. Respective accuracies of 99.65%, 99.73% and 79.03% were reached. A comparison with state-of-art approaches is established to view and compare the key solutions for histopathological image segmentation.

Deep learning for colon cancer histopathological images analysis.

Nowadays, digital pathology plays a major role in the diagnosis and prognosis of tumours. Unfortunately, existing methods remain limited when faced with the high resolution and size of Whole Slide Images (WSIs) coupled with the lack of richly annotated datasets. Regarding the ability of the Deep Learning (DL) methods to cope with the large scale applications, such models seem like an appealing solution for tissue classification and segmentation in histopathological images. This paper focuses on the use of DL architectures to classify and highlight colon cancer regions in a sparsely annotated histopathological data context. First, we review and compare state-of-the-art Convolutional Neural networks (CNN) including the AlexNet, vgg, ResNet, DenseNet and Inception models. To cope with the shortage of rich WSI datasets, we have resorted to the use of transfer learning techniques. This strategy comes with the hallmark of relying on a large size computer vision dataset (ImageNet) to train the network and generate a rich collection of learnt features. The testing and evaluation of such models on our AiCOLO colon cancer dataset ensure accurate patch-level classification results reaching up to 96.98% accuracy rate with ResNet. The CNN models have also been tested and evaluated with the CRC-5000, nct-crc-he-100k and merged datasets. ResNet respectively achieves 96.77%, 99.76% and 99.98% for the three publicly available datasets. Then, we present a pixel-wise segmentation strategy for colon cancer WSIs through the use of both UNet and SegNet models. We introduce a multi-step training strategy as a remedy for the sparse annotation of histopathological images. UNet and SegNet are used and tested in different training scenarios including data augmentation and transfer learning and ensure up to 76.18% and 81.22% accuracy rates. Besides, we test our training strategy and models on the CRC-5000, nct-crc-he-100k and Warwick datasets. Respective accuracy rates of 98.66%, 99.12% and 78.39% were achieved by SegNet. Finally, we analyze the existing models to discover the most suitable network and the most effective training strategy for our colon tumour segmentation case study.1.

Small interfering RNA for cancer treatment: overcoming hurdles in delivery

In many ways, cancer cells are different from healthy cells. A lot of tactical nano-based drug delivery systems are based on the difference between cancer and healthy cells. Currently, nanotechnology-based delivery systems are the most promising tool to deliver DNA-based products to cancer cells. This review aims to highlight the latest development in the lipids and polymeric nanocarrier for siRNA delivery to the cancer cells. It also provides the necessary information about siRNA development and its mechanism of action. Overall, this review gives us a clear picture of lipid and polymer-based drug delivery systems, which in the future could form the base to translate the basic siRNA biology into siRNA-based cancer therapies.

Topical lidocaine-prilocaine cream versus lidocaine infiltration for pain relief during repair of perineal tears after vaginal delivery: randomized clinical trial.

OBJECTIVE: The current study aims to compare the analgesic effect of lidocaine-prilocaine (LP) cream with lidocaine infiltration during repair of perineal tears after vaginal delivery. MATERIALS AND METHODS: A single center open-labeled randomized clinical trial was carried out in a tertiary University Hospital between October 2016 and May 2017 (Clinical Trials.Gov: NCT02883179). We included parous women, who delivered at gestational age >37 weeks with first- or second-degree perineal tears. The participants were randomized in a 1:1 ratio to either lidocaine infiltration (Group I); or application of LP cream (Group II) for pain relief during perineal repair. The primary outcome was the difference in mean pain score during perineal repair. Secondary outcomes included the participants' satisfaction, the need for additional anesthesia, the duration of perineal repair, and the rate of adverse effects of both medications. RESULTS: The study included 144 participants randomized to both groups. The mean pain score during perineal repair was significantly lower in the LP cream group (3.86 ± 1.59) than the lidocaine infiltration group (5.99 ± 1.47) [p = .001]. The duration of repair was significantly shorter in the LP group than the lidocaine infiltration group (6.37 ± 3.68 versus 8.17 ± 2.75 min, respectively, p = .001). The need for additional anesthesia was quite similar in both groups (p = .371). More women in the LP cream group were satisfied than the other group with statistical significant difference (76.4 versus 30.6%, p = .000). No difference between side effects in both groups (p = .171) Conclusions: Topical application of lidocaine-prilocaine cream is an effective analgesic during repair of perineal tears with no harmful side effects.

Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned / 한국역학회지

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned / 한국역학회지

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned / 한국역학회지

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

Congenital anomalies in Tunisia: Frequency and risk factors.

BACKGROUND: Despite the high risk of recurrence of congenital malformations, there are no well-accepted preventive measures in developing countries like Tunisia. It is recommended that thorough epidemiological studies of congenital anomalies in this country are needed. The aim of this study is to assess the frequency and types of congenital anomalies in Tunisia and research some risk factors associated with occurrence of these anomalies. METHODS: In this retrospective study, all the fetuses who were autopsied during 21years period from February 1991 to December 2011 (n=9678) at Service of embryofetopathology in the Center of Maternity and Neonatology of Tunis (CMNT) were studied. The classification of malformations was based upon the anatomical system affected. The differences in fetal/maternal characteristics between cases with or without congenital malformations were assessed using Chi2 test. RESULTS: Of the all 9678 autopsied fetuses, 4498 (46.47%) were diagnosed as being malformed fetuses. Anomalies of limbs (22.71%) and digestive and abdominal wall defects (14.76%) were mostly detected, followed by congenital brain defects (13.41%) and nephrourologic abnormalities (11.23%). A marked association of parental consanguinity with increased congenital anomalies rates was found (P<10-6, OR=1.89, CI=1.69-2.13). CONCLUSION: In Tunisia, surveillance and epidemiological evaluation of congenital anomalies underline the high frequency of these events. This will help to better target congenital anomalies prevention and screening policies in our population.

Influence of Permissive Parenting on Youth Farm Risk Behaviors.

Farm youth continue to experience high rates of injuries and premature deaths as a result of agricultural activities. Increased parental permissiveness is positively associated with many different types of high-risk behaviors in youth. This study explored whether permissive parenting (fathering and mothering) predicts youth unsafe behaviors on the farm. Data were analyzed for 67 youth and their parents. Families were recruited from a statewide farm publication, through youth organizations (i.e., FFA [Future Farmers of America]), local newspapers, farmer referrals, and through the Cooperative Extension Network. Hierarchical multiple regression was completed. Results revealed that fathers and mothers who practiced lax-inconsistent disciplining were more likely to have youth who indulged in unsafe farm behaviors. Key hypotheses confirmed that permissive parenting (lax-inconsistent disciplining) by parents continued to predict youth unsafe farm behaviors, even after youth age, youth gender, youth personality factor of risk-taking, and father's unsafe behaviors (a measure associated with modeling) were all taken into account. A key implication is that parents may play an important role in influencing youth farm safety behaviors. Parents (especially fathers) need to devote time to discuss farm safety with their youth. Farm safety interventions need to involve parents as well as address and respect the culture and values of families. Interventions need to focus not only on safe farm practices, but also promote positive parenting practices, including increased parent-youth communication about safety, consistent disciplining strategies, and increased monitoring and modeling of safe farm behaviors by parents.

[Cigarette smoking initiation among Tunisian adolescents: Risk and protective factors]. / Les facteurs de risque et de protection de l'initiation à la cigarette chez les adolescents tunisiens.

BACKGROUND: Since smoking is a major public health problem among Tunisian teenagers, it is important to identify the underlying risk and protective factors associated with initiation of this behavior. METHODS: A cross-sectional, school-based survey of students was conducted by the Tunisian Ministry of Health among a nationally representative sample of 4172 adolescents aged between 12 and 20 years attending public, private, and professional secondary schools across Tunisia who participated in the Survey of the Health of Tunisian adolescents in 2000. For data analysis, we first calculated crude odds ratios (OR) followed by calculating adjusted OR after using multivariate logistic regression models. RESULTS: Almost one-third of respondents had already started smoking at an average age of 13 years, 6.4% among them smoked daily. Demographic vulnerabilities to smoking behavior were gender (boys more than girls), age and residence in urban areas and particularly in Greater Tunis and the North East. Familial and school factors were parental divorce, poor relationship with parents, poor integration into the peer group, and poor school investment. Psychological and behavioral factors were low self-esteem level and the occurrence of stressful life events, risk taking and alcohol consumption when there was no association with the depression, anxiety and body image. Protective factors against the experimental cigarettes were mainly sports and reading. CONCLUSION: There are many factors associated with smoking behavior among adolescents. All of these predictors need to be considered in smoking prevention among Tunisian teenagers.

Spatial Resolution Improvement of EEG Source Reconstruction Using swLORETA.

Electroencephalography (EEG) and magnetic resonance imaging (MRI) are noninvasive neuro-imaging modalities largely used in neurology explorations. MRI is considered as a static modality and could be so important for anatomy by its high spatial resolution. EEG, on the other hand, is an important tool permitting to image temporal dynamic activities of the human brain. Fusion of these two essential modalities would be hence a so emerging research domain targeting to explore brain activities with the MRI static modality. Our present research investigates a sophisticated approach for localization of the cerebral activity that could be involved by the dynamic EEG modality and carefully illustrated within MRI static modality. Such careful cerebral activity localization would be first based on an advanced methodology yielding therefore a singular value decomposition-based lead field weighting to sLORETA method formalism, for solving in fact the inverse problem in the EEG. The conceived method for source localization, carried out on different cases of simulated dipoles experiments, showed satisfactory results. Different cases of simulated dipoles experiments and metrics were used to confirm the reliability of the proposed method. The experimental results confirm that our method presents a flexible and robust tool for EEG source imaging.

Breast Cancer Ultrasound Images' Sequence Exploration Using BI-RADS Features' Extraction: Towards an Advanced Clinical Aided Tool for Precise Lesion Characterization.

This research concerned a clinical need for precise breast cancer lesion characterization imaged by ultrasound sequences. Using therefore BI-RADS features that would be carefully extracted, the purpose of this study could be mainly to prove and to demonstrate the possibility of surveying precisely the changing characteristics of a breast cancer lesion within a considered ultrasound images' sequence. This was in fact a clinical need of a computer aided diagnosis (CAD) system permitting flexible and convivial clinical analysis of multi-slices' ultrasound breast cancer lesion with greater precision. The obtained results of our images' sequence breast cancer ultrasound analysis had shown the lesion form changing depending on the treated slice, as well as the values' differences for the morphological and the textural features. This would allow extracting more information about breast cancer lesions helping then radiologist to converge more rapidly and with a certain reinforced precision to the accurate clinical action to conduct. Such results would be reassembled and rearranged for constituting one computer aided diagnosis (CAD) system that could be provided for clinical explorations permitting on the other hand to avoid possible confusion between benign and malignant masses.

Pattern of muscle injuries and predictors of return-to-play duration among Malaysian athletes

<p><b>INTRODUCTION</b>The purpose of this study was to investigate the pattern of muscle injuries and the factors that predict the return-to-play duration among Malaysian athletes.</p><p><b>METHODS</b>This is a retrospective review of the case notes of athletes who attended the National Sports Institute Clinic in Malaysia. The medical records of athletes with muscle injury, diagnosed on clinical assessment and confirmed by diagnostic ultrasonography, were included for final analysis.</p><p><b>RESULTS</b>From June 2006 to December 2009, 397 cases of muscle injury were diagnosed among 360 athletes. The median age of the athletes with muscle injuries was 20.0 years. Muscle injuries were mostly diagnosed among national-level athletes and frequently involved the lower limb, specifically the hamstring muscle group. Nearly all of the athletes (99.2%) were treated conservatively. The median return-to-play duration was 7.4 weeks. Athletes who waited more than one week before seeking medical attention, those with recurrent muscle injuries and female athletes were significantly more likely (p < 0.05) to take more than six weeks before returning to the sport.</p><p><b>CONCLUSION</b>Grade 2 lower limb muscle injury was commonly diagnosed among national-level athletes in this study. The frequency of weekly physiotherapy sessions did not affect the return-to-play duration. Factors such as initial consultation at more than one week post injury, recurrent muscle injuries and female gender were significant predictors of return-to-play duration among Malaysian athletes. These predictive factors should be kept in mind during clinical assessment so as to aid in prognosticating recovery after muscle injury.</p>

[Reasons for using emergency departments of major hospitals in Greater Tunis]. / Motifs du recours aux services d'urgence des principaux hôpitaux du Grand Tunis.

Tunisia, similar to many countries, has a problem of overcrowding of the emergency departments (ED). This study aimed to analyse the reasons for using EDs, and to describe the seriousness of the attendees' condition and their itinerary before their arrival at ED. This cross-sectional study in 2009 was conducted in ED of 4 hospitals in GreaterTunis and targeted 1058 patients of both sexes, aged 18 years, with stratification according to time of day of presentation to ED (morning, afternoon and evening). Information was recorded on the sociodemographic characteristics of the study participants, reasons for choosing ED, time of and reason for consultation, diagnosis and severity of illness. Over half the patients (52.5%) were male and the mean age was 46.0 (SD 18.1) years. The main reasons for choosing the ED were: speed (54.0%) and ease of access (47.7%) of ER and occurrence of an acute episode (26.4%). Patients with serious illness accounted for only 6.3% of those interviewed. Implementation of good practices and better coordination between public and private services and the ED are needed to reduce unnecessary visits to ED.

Screening of ΔF508 mutation and IVS8-poly T polymorphism in CFTR gene in Tunisian infertile men without CBAVD.

It is well established that cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations are involved in congenital bilateral absence of the vas deferens (CBAVD), causing obstructive azoospermia and male infertility. Also, several studies reported a relatively high prevalence of CFTR gene mutations in healthy men presenting reduced sperm quality. In this study, we investigate ΔF508 mutation and IVS8-polyT polymorphism in CFTR gene in Tunisian infertile men without CBAVD. Genetic analyses were performed in 148 infertile patients and 126 fertile individuals. The polymorphic IVS8-polyT tract in CFTR gene was analysed in only 129 infertile patients and 54 individuals of control group. As well, we screened for Y chromosome microdeletions in all infertile patients. No ΔF508 mutation was diagnosed either in infertile patients or in control group. 5T allele of IVS8-polyT tract was found in both infertile men (4.26%) and fertile individuals (8.33%). 5T/5T genotype was observed only in two azoospermic patients without Y microdeletions. The most frequent genotype of IVS8-polyT tract in infertile men and controls was 7T/7T (69.75% and 59.25% respectively). There was no association between IVS8-polyT polymorphism and reduced semen quality. Neither ΔF508 mutation nor 5T allele is involved in pathogenesis of male infertility in Tunisian infertile patients without CBAVD.

[Hemogram reference values: study of 1000 healthy adults from Sfax]. / Valeurs de référence de l'hémogramme: étude chez 1000 adultes sains de la region de Sfax.

The aims of this study is to determine the hemogram reference values in a population of healthy adults of the region of Sfax, to compare our results with those from the literature, to estimate the age and sex variations in the blood count. The hemogram parameters were analyzed in 1000 blood donors. Hemogram was performed using Coulter ACT10's analyser. The differential leukocyte count was manually performed. The means of erythrocyte count, hemoglobin, haematocrit and red cell indices were significantly lower in women than in men. There was a significant variation in the red blood cell count, hemoglobin and haematocrit with age. There is also sex and age differences of the leukocyte count. The neutrophil and eiosinophil counts were higher in women than in men. The lymphocytes decreased with age in both sexes. The platelet count was significantly higher in women than in men. These results can be applied only to our local population of adults. The definition of reference values for the Tunisian population requires a study on a more diversified population, including more important number of individuals from various regions of the country.

Reasons for using emergency departments of major hospitals in Greater Tunis

Tunisia, similar to many countries, has a problem of overcrowd ing of the emergency departments [ED]. This study aimed to analyse the reasons for using EDs, and to describe the seriousness of the attendees' condition and their itinerary before their arrival at ED. This cross-sectional study in 2009 was conducted in ED of 4 hospitals in GreaterTunis and targeted 1058 patients of both sexes, aged >/= 18 years, with stratification according to time of day of presentation to ED [morning, afternoon and evening]. Information was recorded on the sociodemographic characteristics of the study participants, reasons for choosing ED, time of and reason for consultation, diagnosis and severity of illness. Over half the patients [52.5%] were male and the mean age was 46.0 [SD 18.1] years. The main reasons for choosing the ED were: speed [54.0%] and ease of access [47.7%] of ER and occurrence of an acute episode [26.4%], Patients with serious illness accounted for only 6.3% of those interviewed. Implementation of good practices and better coordination between public and private services and the ED are needed to reduce unnecessary visits to ED

[Results and evaluation of 3 years of a large scale mammography program in the Ariana area of Tunisia]. / Résultats et évaluation de 3 années de pratique mammographique à grande échelle dans le gouvernorat de l'Ariana en Tunisie.

OBJECTIVE: To asses and analyse the results of 3 years large scale mammography screening of breast cancer in Ariana state in Tunisia. MATERIALS AND METHODS: This program, managed by the Family and Population National Office, was addressing to women aged from 49 to 69 years old residing in a area with adds up a population of 459 700 inhabitants including 52,729 women in the target age population. The screening was including a breast clinical examination and a mammography with two incidences face and external profile. The women was invited at their residence or were sensitized in the reproductive health centers, care and base health centers or by a close relation which heard of the program. An enlightened assent was submitted to the women who wished to profit from the screening. RESULTS: In three years, 9093 mammography were carried out of which 8244 were retained in the analyses, that is to say a rate participation of 9.6%. The rate of women recalled for suspect test was of 18.1% and it was of 13.1% among women of more than 50 years. The rate of practiced surgical biopsies was of 0.5% and the positive predictive value was of 45.5%. The average time between the date of screening and the result of the screening was 9.7 days, more important in the event of tests requiring a complementary assessment (61.7 days). On the whole 40 cancers were detected by the program, that is to say a rough rate of detected cancers, of 4.9 per thousand, in conformity with the recommendations. The percentage of invasive cancers < or = 10 mm was of 24.3 whereas percentages of in situ cancers and of cancers without ganglionic invasion were respectively of 7.7% and of 50.0%. CONCLUSIONS: The weakness of our study lay primarily in the rate of participation which remained weak. The methodology adopted for the sensitizing of the women is proven not very effective and did not allow inviting all eligible women. Results of the study are encouraging in spite of its limited impact and made it possible to detect an important rate of cancers of which cancers infra-private clinics.

[Preliminary results and analysis of the feasibility of mammographic breast cancer screening in women younger than 50 years of the Ariana area in Tunisia]. / Résultats préliminaires et faisabilité du dépistage mammographique du cancer du sein chez les femmes de moins de 50 ans du gouvernorat de l'Ariana en Tunisie.

OBJECTIVE: To report the preliminary results of the feasibility of breast cancer mammographic screening among women younger than 50 years from the l'Ariana state of Tunisia. MATERIAL AND METHODS: The National office of the Family and Population (ONFP) launched a protocol on feasibility of breast cancer mammographic screening targeting asymptomatic women aged 40-69 years, from the l'Ariana state in Tunisia. We practiced two oblique and face incidences at the mammography screening unit of the ONFP, whose equipment and control system of quality answered to the European Communitiy for breast cancer screening. RESULTS: We did 5325 mammograms between April 2004 and March 2006. Our targeted population had a 48.9 years mean age (CI 95% = [48.7-49.1]), 60.3% of them younger than 50 years. There were more young women with high breast denisty (8.2%) compared to the group from 50 to 69 years (2.1%). The women arising from the 40-49 years cohort had a socio-economic and educational level higher. The complementary rate of examination/explorations was higher in this cohort (19.5%) vs 11.5% for the 50-69 years. The youngest women presented a more often positive test (7.0 vs 5.2%) than the oldest women (p<0.01). CONCLUSION: The option to screen breast cancer by mammography in women younger than 40 years in Tunisia is partially justified by the relatively high frequency of this cancer in this age group. Our feasibility poorly useful in screening will be used to sensibilise females to the problematic of breast cancer to obtain a better compliance compared to the older age group of 50-59 years.

[Estimation of years of life gained within the pilot screening program of the Ariana area of Tunisia]. / Estimation du nombre potentiel d'années de vie sauvées à travers l'expérience pilote de dépistage de masse du cancer du sein à l'Ariana.

Breast cancer is the principle cancer among female cancer in Tunisia. It represents 30% of the woman's cancers with about 1000 new cases per year. The main intervention control is mass screening using mammography in to reduce breast cancer mortality. Breast cancer screening efficacy in term of breast cancer mortality reduction is closely related to incidence and survival of this cancer. National Office of Family and Population (ONFP) conducted a pilot experience of breast cancer mass screening using the mammography in place. The main objective of this study is to calculate the potential number of life years saved through this pilot experience of the ONFP. For the methodology, we used the software Dismod (Disease Model) for the evaluation of the prevalence and the duration of the cancer of the breast in the governorate, as well as to estimate the number of life years saved. The potential breast cancer mortality reduction is 30% for women aged of 50 at 69 years, and 10% for those aged of 40 at 49 years. Breast cancer incidence in Ariana according to age for the period 1995-1998, has been calculated from the data base of cancer registry of the North of Tunisia. According to Dismod, mean duration in the absence of screening, is 11.12 years for the age group 40 to 49 years and 9.57 for the age group 50 at 69 years. Screening would increase these duration means of 2.22 years and 1.71 years, respectively for age groups 40 to 49 years and 50 at 69 years. The number of life years saved for 1000 women is of 2.97 years. In conclusion breast cancer screening using mammography would be actually little benefit in Tunisia. Mammography should be reserved for the diagnosis of the suspected cases and screening for high risk women.