Formerly known as Duke C colon cancer, stage 3 is a stage where the tumor has spread beyond its original site in the mucosa, or the first layer of the colon, into the serosa, the outermost layer. There, the tumor breeds while waiting to travel into a lymph node or blood vessel that will transport it to distant body parts.
Differentiating 3A, 3B and 3C
Stage 3 colon cancer is divided into three groups, from least advanced to most advance. The earliest stage is known as Stage 3A (formerly Duke C1), the middle stage is Stage 3B (Duke C2) and the most advanced stage is Stage 3C (Duke C3).