Vesna Zadnik

Dr. Vesna Zadnik

Epidemiology and Cancer Registry, Institute of Oncology Ljubljana, Ljubljana, Slovenia

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 August 2018 in BMC Medicine
Verified
Journal Article
Open access
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Lei HuangLei Huang
Lei Huang
LJLina Jansen
Lina Jansen
YBYesilda Balavarca
Yesilda Balavarca
MBMasoud Babaei
Masoud Babaei
LGLydia van der Geest
Lydia van der Geest
HBHermann Brenner
Hermann Brenner
The prognosis of pancreatic cancer (PaC) strongly varies across different stages and age groups, which has unfortunately not been well recorded in the literature. This international population-based study aimed to provide tumor-node-metastasis (TNM) stage- and age-specific survival estimates and trends in resected and overall (resected and unresected) PaC in the early twenty-first century. Using data from the US Surveillance, Epidemiology, and End Results-18 Program and the national cancer registries of the Netherlands, Belgium, Norway, and Slovenia, short-term and long-term overall survival results stratified by TNM stage and age in resected and overall primary PaC, irrespective of being microscopically confirmed or not, in 2003–2014 were computed using the Kaplan-Meier method. The temporal survival trends over three predefined periods (2003–2005, 2006–2008, and 2009–2011) were further examined using the log-rank test. In total, data for 125,183 patients were analyzed. Overall, age-stratified 3-year survival was 20–34% (< 60 years), 14–25% (60–69 years), and 9–13% (≥ 70 years) in stages I–II PaC; and 2–5% (< 60 years), 1–2% (60–69 years), and < 1–1% (≥ 70 years) in stages III–IV cancer. Patients who underwent operation had higher 3-year survival in each stage and age group (stages I–II: 23–39% (< 60 years), 16–31% (60–69 years), and 17–30% (≥ 70 years); stages III–IV: 5–19% (< 70 years) and 2–14% (≥ 70 years)). Perioperative survival also decreased with advancing stage and older age (stages I–II: 98–100% (< 60 years), 97–99% (60–69 years), and 94–99% (≥ 70 years); stages III–IV: 94–99% (< 70 years) and 81–96% (≥ 70 years)). Between 2003 and 2005 and 2009–2011, for overall PaC, both short-term and long-term survival improvements were observed in all countries except Belgium; for resected disease, short-term improvements were present only in the USA and Slovenia, but long-term improvements were observed in all countries except Slovenia, with stage-specific variations. Our large international study provides TNM stage- and age-specific population-based survival in overall and resected PaC that will facilitate clinical counseling. While the survival expectations for patients with resected PaC are substantially higher than the widely available and known dismal survival predictions for overall patients, conclusions on the benefits of resection cannot be made from this observational study. Patients with advanced-stage disease and/or older age should undergo careful risk assessment before treatment. Limited but inspiring improvement in survival is observed.

19 February 2020 in Radiology and Oncology
Verified
Journal Article
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AMAna Mihor
Ana Mihor
STSonja Tomsic
Sonja Tomsic
TŽTina Žagar
Tina Žagar
KLKatarina Lokar
Katarina Lokar
VZVesna Zadnik
Vesna Zadnik
Background: Since the end of the previous century, there has not been a comprehensive review of European studies on socioeconomic inequality in cancer incidence. In view of recent advances in data source linkage and analytical methods, we aimed to update the knowledge base on associations between location-specific cancer incidence and individual or area-level measures of socio-economic status (SES) among European adults. Materials and methods: We systematically searched three databases ( PubMed, Scopus and Web of Science ) for articles on cancer incidence and SES. Qualitative synthesis was performed on the 91 included English language studies, published between 2000 and 2019 in Europe, which focused on adults, relied on cancer registry data and reported on relative risk (RR) estimates. Results: Adults with low SES have increased risk of head and neck, oesophagogastric, liver and gallbladder, pancreatic, lung, kidney, bladder, penile and cervical cancers (highest RRs for lung, head and neck, stomach and cervix). Conversely, high SES is linked with increased risk of thyroid, breast, prostate and skin cancers. Central nervous system and haematological cancers are not associated with SES. The positive gap in testicular cancer has narrowed, while colorectal cancer shows a varying pattern in different countries. Negative associations are generally stronger for men compared to women. Conclusions: In Europe, cancers in almost all common locations are associated with SES and the inequalities can be explained to a varying degree by known life-style related factors, most notably smoking. Independent effects of many individual and area SES measures which capture different aspects of SES can also be observed.

22 February 2017 in Radiology and Oncology
Verified
Journal Article
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VZVesna Zadnik
Vesna Zadnik
MZMaja Primic Zakelj
Maja Primic Zakelj
KLKatarina Lokar
Katarina Lokar
KJKatja Jarm
Katja Jarm
UIUrska Ivanus
Urska Ivanus
TŽTina Žagar
Tina Žagar
Background: The aim of our study was to describe cancer burden and time trends of all cancers combined, the most frequent as well as the rare cancers in Slovenia. Patients and methods: The principal data source was the population-based Cancer Registry of Republic of Slovenia. The cancer burden is presented by incidence and prevalence for the period 1950–2013 and by mortality for years 1985–2013. The time trends were characterized in terms of an average annual percent change estimated by the log-linear joinpoint regression. The Dyba-Hakulinen method was used for estimation of incidence in 2016 and the projections of cancer incidence for the year 2025 were calculated applying the Globocan projection software. Results: In recent years, near 14,000 Slovenes were diagnosed with cancer per year and just over 6,000 died; more than 94,000 people who were ever diagnosed with cancer are currently living among us. The total burden of cancer is dominated by five most common cancer sites: skin (non-melanoma), colon and rectum, lung, breast and prostate, together representing almost 60% of all new cancer cases. On average the incidence of common cancers in Slovenia is increasing for 3.0% per year in last decade, but the incidence of rare cancers is stable. Conclusions: Because cancer occurs more among the elderly, and additionally more numerous post-war generation is entering this age group, it is expected that the burden of this disease will be growing further, even if the level of risk factors remains the same as today.

29 July 2020 in Radiology and Oncology
Verified
Journal Article
Open access
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VZVesna Zadnik
Vesna Zadnik
AMAna Mihor
Ana Mihor
STSonja Tomsic
Sonja Tomsic
TŽTina Žagar
Tina Žagar
NBNika Bric
Nika Bric
IOIrena Oblak
Irena Oblak
Background: The COVID-19 pandemic has disrupted the provision and use of healthcare services throughout the world. In Slovenia, an epidemic was officially declared between mid-March and mid-May 2020. Although all non-essential health care services were put on hold by government decree, oncological services were listed as an exception. Nevertheless, as cancer control depends also on other health services and additionally major changes in people’s behaviour likely occurred, we aimed to analyse whether cancer diagnosis and management were affected during the COVID-19 epidemic in Slovenia. Methods: We analysed routine data for the period November 2019 through May 2020 from three sources: (1) from the Slovenian Cancer Registry we analysed data on pathohistological and clinical practice cancer notifications from two major cancer centres in Ljubljana and Maribor; (2) from the e-referral system we analysed data on all referrals in Slovenia issued for oncological services, stratified by type of referral; and (3) from the administrative data of the Institute of Oncology Ljubljana we analysed data on outpatient visits by type as well as on diagnostic imaging performed. Results: Compared to the November 2019 – February 2020 average, the decrease in April 2020 was about 43% and 29% for pathohistological and clinical cancer notifications; 33%, 46% and 85% for first, control and genetic counselling referrals; 19% (53%), 43% (72%) and 20% (21%) for first (and control) outpatient visits at the radiotherapy, surgery and medical oncology sectors at the Institute of Oncology Ljubljana, and 48%, 76%, and 42% for X-rays, mammograms and ultrasounds performed at the Institute, respectively. The number of CT and MRI scans performed was not affected. Conclusions: Significant drops in first referrals for oncological services, first visits and imaging studies performed at the Institute, as well as cancer notifications in April 2020 point to a possibility of a delayed cancer diagnosis for some patients during the first surge of SARS-CoV-2 cases in Slovenia. The reasons for the delay cannot be ascertained with certainty and could be linked to health-seeking behaviour of the patients, the beliefs and practices of doctors and/ or the health system management during the epidemic. Drops in control referrals and control visits were expected and are most likely due to the Institute of Oncology Ljubljana postponing non-essential follow-ups through May 2020.

25 March 2019 in BMC Medicine
Verified
Journal Article
Open access
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Lei HuangLei Huang
Lei Huang
YBYesilda Balavarca
Yesilda Balavarca
LGLydia van der Geest
Lydia van der Geest
VLValery Lemmens
Valery Lemmens
EEElizabeth Jozefa Van Eycken
Elizabeth Jozefa Van Eycken
LJLina Jansen
Lina Jansen
Pancreatic cancer (PaC) remains extremely lethal worldwide even after resection. PaC resection rates are low, making prognostic studies in resected PaC difficult. This large international population-based study aimed at exploring factors associated with survival in patients with resected TNM stage I–II PaC receiving chemotherapy and at developing and internationally validating a survival-predicting model. Data of stage I–II PaC patients resected and receiving chemotherapy in 2003–2014 were obtained from the national cancer registries of Belgium, the Netherlands, Slovenia, and Norway, and the US Surveillance, Epidemiology, and End Results (SEER)-18 Program. Multivariable Cox proportional hazards models were constructed to investigate the associations of patient and tumor characteristics with overall survival, and analysis was performed in each country respectively without pooling. Prognostic factors remaining after backward selection in SEER-18 were used to build a nomogram, which was subjected to bootstrap internal validation and external validation using the European datasets. A total of 11,837 resected PaC patients were analyzed, with median survival time of 18–23 months and 3-year survival rates of 21–31%. In the main analysis, patient age, tumor T stage, N stage, and differentiation were associated with survival across most countries, with country-specific association patterns and strengths. However, tumor location was mostly not significantly associated with survival. Resection margin, hospital type, tumor size, positive and harvested lymph node number, lymph node ratio, and comorbidity number were associated with survival in certain countries where the information was available. A median survival time- and 1-, 2-, 3-, and 5-year survival probability-predictive nomogram incorporating the backward-selected variables in the main analysis was established. It fits each European national cohort similarly well. Calibration curves showed very good agreement between nomogram-prediction and actual observation. The concordance index of the nomogram (0.60) was significantly higher than that of the T and N stage-based model (0.56) for predicting survival. In these large international population-based cohorts, patients with resected PaC receiving chemotherapy have distinct characteristics independently associated with survival, with country-specific patterns and strengths. A robust benchmark population-based survival-predicting model is established and internationally validated. Like previous models predicting survival in resected PaC, our nomogram performs modestly.

KLKatarina Lokar
Katarina Lokar
TŽTina Žagar
Tina Žagar
VZVesna Zadnik
Vesna Zadnik
Ecological deprivation indices at the level of spatial units are often used to measure and monitor inequalities in health despite the possibility of ecological fallacy. For the purpose of this study, the European Deprivation Index (EDI) was used, which is based on Townsend theorization of relative deprivation. The Slovenian version of EDI (SI-EDI) at the aggregated level (SI-EDI-A) was calculated to the level of the national assembly polling stations. The SI-EDI was also calculated at the individual level (SI-EDI-I) by the method that represents a methodological innovation. The degree of ecological fallacy was estimated with the Receiver Operating Characteristics (ROC) curves. By calculating the area under the ROC curve, the ecological fallacy was evaluated numerically. Agreement between measuring deprivation with SI-EDI-A and SI-EDI-I was analysed by graphical methods and formal testing. The association of the socio-economic status and the cancer risk was analysed in all first cancer cases diagnosed in Slovenia at age 16 and older in the period 2011–2013. Analysis was done for each level separately, for SI-EDI-I and for SI-EDI-A. The Poisson regression model was implemented in both settings but adapted specifically for aggregated and individual data. The study clearly shows that ecological fallacy is unavoidable. However, although the association of cancer incidence and socio-economic deprivation at individual and aggregated levels was not the same for all cancer sites, the results were very similar for the majority of investigated cancer sites and especially for cancers associated with unhealthy lifestyles. The results confirm the assumptions from authors’ previous research that using the level of the national assembly polling stations would be the acceptable way to aggregate data when explaining inequalities in health in Slovenia in ecological studies.