Desley van Zoggel

Scientific and societal impact 155 CHAPTER 9 Scientific and societal impact Rectal cancer is a major cause of morbidity and mortality across the world. As surgical technique for treatment of primary rectal cancer has improved, the incidence of locally recurrent rectal cancer (LRRC) has decreased. However, patients who do develop LRRC have a high risk of progressive disease, leading to high morbidity and mortality risks. As described in chapter 1 of this thesis, LRRC has a completely different aetiology and treatment needs to be tailored. The most important factor influencing survival remains surgical resection with clear resection margins, meaning no tumour cells are left behind. Surgical resection of LRRC unfortunately often entails extended, debilitating procedures. Over the past years, different treatment modalities have been implemented, with the goal of facilitating surgical resection and therefore improving outcomes. However, as pictured in the historical figure, 3-year and 5-year overall survival has not greatly improved over the past 30 years.1–3 These numbers might be biased by patient selection. Highly specialised centres, treating the majority of LRRC patients and therefore able to publish large datasets, are usually also tertiary referral centres that accept more and more highly advanced cases. This thesis focusses on the addition of induction chemotherapy and found that it improved the rate of pathological complete response, which also leads to better survival rates. Figure. Progress in overall survival rates for LRRC over the years van Zoggel Voogt/van Zoggel 0 10 20 30 40 50 60 70 1990 1995 2000 2005 2010 2015 2020 2025 Overall survival % Progress in overall survival rates for LRRC over the years 3-year overall survival 5-year overall survival