Greifswalder microbiome analysis colorectal cancer

Interventions: Group 1: Arm 1 - colon cancer -> 16sRNA microbiome analysis (stool at time of initial diagnosis/ stool post operative/ stool during follow up; healthy normal tissue of the proximal and distal resection margin; tumor tissue) Group 2: Arm 2 - rectal cancer -> 16sRNA microbiome analysis (stool examination at time of initial diagnosis/ if neoad. therapy than stool examination after completion of neoadj. therapy/ stool examination post operative and during follow up; healthy normal tissue of the proximal and distal resection margin; tumor tissue) Primary outcome(s): 16sRNA analysis of the microbiome (stool at initial diagnosis and postoperatively at primary surgery, or before neoadj. therapy and after completion, tumor tissue intraoperatively) in patients with CRC. Study Design: Allocation: ; Masking: ; Control: ; Assignment: ; Study design purpose: other