Disputation: Anna Lisa Schult

Anna Lisa Schult defended her thesis entitled "Performance of two screening tests and barriers to colorectal cancer screening", Thursday 17 March.
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The public defence took place digitally, with main supervisor Thomas de Lange and closest colleagues gathered at the Cancer Registry's premises.

Parts of the bowel screening section together with the doctoral candidate


The Adjudication Committee consisting of Dr. Roland Valori of Gloucerstershire Royal Hospital, UK; PhD Anna Forsberg at Karolinska Institutet, Sweden and Associate Professor Marte Lie Høivik, University of Oslo, participated in the public defence digitally.

The public defence was led by Professor Arnljot Tveit, University of Oslo.

The trial lecture and the defence itself went brilliantly, the Cancer Registry of Norway congratulations!

Main supervisor Thomas de Lange and Anne Lisa Schult Digital disputation: Anna
Lisa Schult
and first opponent Roland ValoriHovedveileder Professor Thomas de Lange, og PhD-kanditat Anne Lisa Schult


Bowel cancer is a major health burden. Screening can reduce both incidence and mortality of this disease. Endoscopic screening with sigmoidoscopy or colonoscopy and testing for blood in the stool are the most commonly used methods, but these two methods have not been compared directly previously. The effectiveness of screening depends on the test used, but also on high participation in screening. Concern about colonoscopy pain can be a barrier to participation in bowel screening. Women are at higher risk for painful colonoscopies than men. The absence of bowel symptoms may be another barrier to screening participation, as asymptomatic individuals show a lower adherence to screening programs.

Anna's doctoral thesis is based on data from a large Norwegian randomized bowel screening study. Approximately 140,000 people were invited for either sigmoidoscopy or repeated testing for blood in the stool (immunochemical fecal occult blood test - iFOBT).

The results showed that the participation rate in iFOBT screening was higher than with sigmoidoscopy screening. Several cases of bowel cancer and advanced precancerous lesions were detected by iFOBT screening, and most cases of cancer and possible precancerous conditions were detected in screening participants without symptoms. Women who received painkillers before colonoscopy reported fewer painful colonoscopies than women who were treated with painkillers when needed.

The comparable effectiveness of sigmoidoscopy and iFOBT screening is unknown until results from long-term follow-up are available. Nevertheless, this study has provided important information for planning a national screening programme for colorectal cancer. The results further highlight the importance of encouraging people without symptoms to participate in screening programmes. It was also shown that painkillers should be offered to women before the colonoscopy examination starts. Optimized pain relief during colonoscopy can have an impact on the reputation of screening and thus increase the participation rate and effectiveness of endoscopic screening.


The doctoral candidate

Anna Lisa Schult has been employed as a PhD candidate at the Bowel Screening Section since 2015. In her project, Anna has worked with baseline data from the Pilot Project and is otherwise particularly interested in pain relief during colonoscopy.


Anna is a medical doctor from RWTH Aachen, Germany and moved to Norway after completing her medical studies in 2007.

She is currently undergoing specialization in Gastroenterology and internal medicine and has worked at Innlandet Hospital, Elverum and Vestre Viken HF, Bærum Hospital before she was employed at the Cancer Registry. Since 2012 she has also performed endoscopies in the Pilot Project at the screening centre in Bærum.

Anna also has a PhD on renal fibrosis from Germany.