Symptoms of colorectal cancer metastasis

There are no obvious symptoms in the early stage of rectal liver metastasis. A few patients may experience discomfort or dull pain in the upper abdomen or liver area, or symptoms such as loss of appetite, nausea and vomiting. As the disease progresses, jaundice, ascites, edema, cachexia, masses in the anterior rectal fossa, and supraclavicular lymph node enlargement may appear, indicating distant spread and metastasis of the tumor.

The main symptoms of rectal cancer metastasis are:

(I) Infiltration: The speed of infiltration along the longitudinal axis of the intestinal tract is slow, and the infiltration distance is small, rarely exceeding the edge of the tumor by 2 to 3 centimeters. Infiltration along the horizontal direction is slightly faster than that along the longitudinal direction, and it can infiltrate 1/4 of the intestinal tract in about half a year, and it takes about one and a half to two years to infiltrate one week, which is also relatively slow compared with other digestive tract tumors. In addition, after the tumor infiltrates deeply to the entire layer, it can spread to adjacent tissues and organs, and can adhere to and fix with surrounding tissues and organs.

(II) Lymphatic metastasis Lymphatic drainage above the dentate line of the rectum is divided into three groups: upper, middle, and lower. It goes upward along the posterior rectal lymph nodes or presacral lymph nodes through the lymph nodes beside the common iliac vessels or the lymph nodes at the root of the mesentery to the abdominal aortic lymph nodes. The middle group extends to the inner side of the pelvic diaphragm on both sides, spreads through the lymph nodes within the lateral ligament to the internal iliac lymph nodes and then goes upward. The lower group passes through the pelvic diaphragm through the lymph nodes within the ischiorectal fossa to the internal iliac lymph nodes, and goes downward through the sphincter and anal skin to the inguinal lymph nodes. Generally, most of the rectal lymphatic drainage above 8 cm from the anal verge runs in the upper and middle directions, but the lymphatic vessels can also drain downward when they are blocked by cancer cells. Most of the rectal lymphatic drainage below 8 cm from the anal verge is downward, so the resection of the cancer in this section of the rectum should be removed together with the anus and the fat around it. The chance of lymphatic metastasis of rectal cancer is greater than that of colon cancer, and the probability is higher the lower it is.