About me

Shaohua Xie is Principal Researcher and Docent  in Cancer Epidemiology working in the research group of Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery. 

Shaohua Xie is member of the Reference Group for International Affairs of Karolinska Institutet and has been mainly involved in alumni activities.

Research description

My research interests focus on cancer epidemiology. I am currently working on the epidemiology of upper gastrointestinal cancers, particularly that of esophageal adenocarcinoma. 

I am also interested in the epidemiology of other types of cancers and environmental health issues.


Trends and Disparities in Oesophageal and Gastric Cancers

I have been interested in the time trends and disparities across regions and social groups in oesophageal and gastric cancers. We have assessed the time trends in the incidence of these cancer in Sweden and in other parts of the world (Cancer Epidemol 2016, 2017; Int J Cancer 2017; Clin Epidemiol 2018; Acta Oncol 2018). We have reviewed existing literature on the social group disparities in the incidence and prognosis of oesophageal cancer (United European Gastroenterol J 2018). Our recent study found considerable geographic disparities in the incidence and tumour stage distribution of oesophageal cancer in Sweden (Scand J Gastroenterol 2020). We also finished quantitative analyses of the racial/ethnic disparities in the incidence of oesophageal and gastric cancers in the United States, using a panel of health disparity measures (Am J Epidemiol 2017; Cancer Res Treat 2019).


The Mysterious Male Predominance in Oesophageal Adenocarcinoma

Oesophageal adenocarcinoma is characterised by a marked and enigmatic sex difference in incidence, with the male-to-female incidence ratio as high as 8-to-1 in Northern America and 6-to-1 in Europe. Sex hormonal factors may play a role in the development of this cancer. I have summarised the existing evidence on this topic in my review article (Clin Gastroenterol Hepatol 2016). My research has been focused on disentangling this mysterious male predominance in oesophageal adenocarcinoma and the role of sex hormonal exposures, with different epidemiological approaches. Particularly, in a case-control study nested in a prospective Norwegian cohort and a meta-analysis of existing studies, we found a decreased risk of oesophageal adenocarcinoma associated with higher testosterone levels in men (Am J Gastroenterol 2020). Our Mendelian randomisation analysis revealed causal effects of follicle-stimulating hormone and luteinising hormone on the risk of oesophageal adenocarcinoma (Clin Gastroenterol Hepatol 2020).


Diabetes and Metformin Use in Relation to Oesophageal and Gastric Cancers

Diabetes and common anti-diabetes medications may influence the risk and prognosis of cancer. We are particularly interested in the role of diabetes and use the first-line anti-diabetes drug metformin in oesophageal and gastric cancers. We have examined the association how diabetes influence the risk and prognosis of gastric adenocarcinoma in population-based cohorts in Sweden (Br J Surg 2018; Br J Cancer 2019). To investigate common medications in relation to cancer risk and other health outcomes, we have established a nationwide cohort of 8.4 million users of selected common medications, using data from several health data registers in Sweden (BMJ Open 2019). We have found that metformin use may decrease risk of oesophageal squamous cell carcinoma but not gastric cancer (Br J Cancer 2019; Am J Gastroenterol 2020).


Precision Prevention of Oesophageal Cancer

Oesophageal cancer carries a poor prognosis, with an overall 5-year survival below 15-20%. Upper endoscopy is increasingly utilized for detection of the premalignant conditions which might improve survival. However, a universal screening strategy is not feasible given the considerable costs and risk of complications, and the low incidence of oesophageal cancer. Identifying a limited group of individuals at high absolute risk of oesophageal cancer for endoscopic screening would be more favourable. We have been developing and validating risk prediction models for oesophageal cancer based on information on a panel of readily identifiable risk factors, and evaluating the feasibility of targeted screening based on individual risk assessment (Int J Cancer 2016; Epidemiology 2017; Am J Gastroenterol 2018; Clin Gastroenterol Hepatol 2018; Gastrointest Endosc 2018; Gastroenterology 2019; Am J Gastroenterol 2020.). We have also developed a model predicting long-term survival in patients who have undergone oesophageal cancer surgery (Ann Surg 2021).

Successful prevention of oesophageal cancer is dependent on availability of effective preventive measures or interventions. In a systematic review and meta-analysis of 52 studies, we have found that smoking cessation time-dependently decreases risk of oesophageal squamous cell carcinoma, but has limited influence on the risk of oesophageal adenocarcinoma (J Natl Cancer Inst 2017).

"Oesophageal Adenocarcinoma Risk Assessment Tool" and "Prediction of survival after esophageal cancer surgery" are available through the links on the left.

Teaching portfolio


I am currently main supervisor of a PhD student, Sirus Rabbani, in our research group. 

I was co-supervisor of two PhD candidate, Drs. Jiaojiao Zheng and Qiaoli Wang, who successfully defended her thesis in 2021 and 2020, respectively, at Karolinska Institutet.

I warmly welcome medical and master students to carry out their degree projects with me. Medical students who worked with me have authored publications in scientific journals, including Am J Gastroenterol and Am J Epidemiol.


Study design in clinical research (KI PhD course 2980, previously 1794)


2013    PhD in Public Health, The Chinese University of Hong Kong, Hong Kong SAR, China

Thesis title: Domestic Incense Burning and the Risk of Nasopharyngeal Carcinoma: A Case-Referent Study among Hong Kong Chinese

Supervisors: Prof. Ignatius Tak-sun Yu (main supervisor) & Prof. Shelly Lap-Ah Tse

2007    Bachelor of Medicine in Preventive Medicine (major), Huazhong University of Science and Technology, Wuhan, China

2007    Bachelor of Arts in English (minor), Huazhong University of Science and Technology, Wuhan, China


Other trainings

2020.11 - 2021.06         Professional Certificate in Pharmacoepidemiology & Pharmacovigilance, London School of Hygiene & Tropical Medicine

2012.03 - 2012.06        Visiting Scientist at Harvard School of Public Health, Boston, USA (Hosted by Prof. Alex Chensheng Lu)

2009.04                        Yale - China CDC Workshop on Environmental Epidemiology, Suzhou, China

Academic honours, awards and prizes


Cancerfonden (Swedish Cancer Society), 2020-2022, 1 800 000 SEK (Principle investigator)

Clinical Scientist Training Programme (CSTP), 2018-2022, 1 280 000 SEK (Main applicant as a PhD supervisor) 

Ihred Fund, the Swedish Society of Medicine, 2016-2020, 505 000 SEK (Principle investigator)

Ruth and Richard Julin Foundation, 2016-2021, 700 000 SEK (Principle investigator)

KI Research Foundation Grant, 2016-2020, 132 200 SEK (Principle investigator)

Research environment grant within register-based research, Swedish Research Council, 2019 - 2023, 13 000 000 SEK (Co-investigator)

Cancer Research UK, 2018 - 2020, 161,138 GBP (Co-investigator)

China - Sweden Network Grant for Research Collaboration, the Swedish Research Council, 2016 - 2017, 700 000 SEK (Co-investigator)

National Natural Science Foundation of China, 2011 - 2013, 370,000 CNY; 2012 - 2013, 160,000 CNY; 2014 - 2017, 700,000 CNY (Co-investigator)

Other Awards

Tongji Medical College Overseas Alumni Association - Sehngquan Zou Outstanding Clinical
Junior Research Award (2020)

Global Scholarship Program for Research Excellence - CNOOC Grants and trained at Harvard School of Public Health in 2012, 30 000 HKD

Research Postgraduate Students' Research / Conference Grant, The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, 2009-2013 , 40 000 HKD