Background and aim: Colorectal Cancer (CRC) is one of the most frequent cancer entities in the western world. It is known that obesity is one of the major risk factors for CRC. In contrast, mild obesity seems to have a positive effect on postoperative outcome, which is known as the "obesity paradox". Also, the number of resected lymph nodes (LN) during surgery is very important for correct staging. The aim of the present project is to evaluate the impact of BMI and LN-yield on long term overall survival (OS) of CRC patients treated with curative intent.

Methods: Patients treated for CRC between 1998 and 2011 at the Klinik Favoriten in Vienna, Austria were analyzed in this retrospective single-center cohort analysis concerning OS.

Inclusion Criteria:

• colorectal carcinoma
• treated at the Klinik Favoriten between 1998 and 2011
• elective or acute surgical setting
• curative intent
• older than 18 years

Exclusion Criteria:

• other carcinoma (anal, metastases, ...)
• treated before 1998 or after 2011
• palliative intent
• younger than 18 years

Patients who had surgery at the department of surgery at the Klinik Favoriten between 1998 and 2011 were analyzed. 1192 patients met the inclusion criteria were therefore pseudonymized and recorded in a newly developed database.

All relevant data will be shared within a publication of the study. Detailled data are available upon request