Deformation and thinning of the fecal column
Introduction
Introduction The early manifestation of rectal cancer is that the fecal column is thinned and the late stage is incomplete obstruction. Rectal cancer refers to cancer located between the dentate line to the sigmoid colon and the rectal junction. Is the common incidence of malignant tumors in the gastrointestinal tract after gastric and esophageal cancer is the most common part of colorectal cancer (accounting for about 60%). Most genetic patients account for more than 15% of men over 40 years old and under 30 years old. Seeing the ratio of male to female is 2-3:1, rectal cancer is a lifestyle disease. At present, it has jumped to the second place in the cancer rankings, so diet, lifestyle, is the bane of cancer.
Cause
Cause
Causes
Dietary factors: fat, cellulose and calories.
Risk factors for colorectal cancer can be classified into relative risk and absolute risk. Dietary factors play an extremely important role in the development of colorectal cancer. Currently, colorectal cancer accounts for the second place in malignant tumors worldwide, and it ranks second in western developed countries, and it ranks only eighth in some underdeveloped countries. Epidemiological observations and experimental studies have shown that diet has a decisive role in the development of colorectal cancer. The increase in fat consumption is parallel with the increase in the incidence of colorectal cancer. Direct determination of dietary fat content indicates that people with high fat consumption, The mortality rate of colorectal cancer is also high. Immigration studies from the low-fat diet to the high-fat diet found that the incidence of colorectal cancer was significantly higher than in the original country. Immigrants from Japan to Hawaii have a significant increase in colon cancer deaths, and immigrants from Poland to Australia have also seen this increase in mortality.
The biochemical mechanism of food fat in promoting cancer in the colon has not been confirmed, and there are several mechanisms:
1 food fat causes an increase in steroids in the bile, while the latter has a damaging effect on the colonic epithelium and can cause excessive proliferation of the colonic epithelium;
2 The free radicals produced during lipid peroxidation promote carcinogenesis;
3 certain fatty acids promote carcinogenesis by binding to cell membranes, causing changes in cell membrane fluidity and changes in carcinogen response;
4 too much linoleic acid can increase the synthesis of certain prostaglandins, while the latter acts as a cancer-promoting agent to stimulate cell proliferation;
5 food fat determines the nature of intestinal bacteria, and intestinal bacteria play an important role in the metabolism of carcinogens;
6 The carcinogenic effect of fat is not related to its chemical composition, but related to its heat card density. Because fat has the highest heat card density, it is the most carcinogenic.
It is not yet known what level of food fat should be limited to reduce its carcinogenic effect on the colon. In the United States and some Western European countries, the average fat content accounts for about 40% of total calories, which is related to fat in third world countries. A clear comparison of only 10% to 25% of total calories, animal studies have shown that when food fat increases from 10% to 40% of total calories, there is a dose effect that induces colon tumors.
Another factor associated with colorectal cancer in the diet is cellulose. Burkitt and Trowell first suggested that the black African diet contains higher levels of cellulose, so the mortality rate of colorectal cancer is lower than that of whites, while whites consume very little cellulose. However, the results of epidemiological studies since then are inconsistent. This inconsistency may be due to food cellulose not being one.
Examine
an examination
Related inspection
Fecal traits, routine rectal examination, proctoscopy, fecal occult blood test (OBT)
Clinical manifestations of rectal cancer
Rectal cancer is often asymptomatic in the early clinical stage, or the symptoms are not specific, so it often does not attract the attention of patients and newly diagnosed physicians. Most patients may have bowel habit changes and blood in the stool in the early stage, showing frequent frequency and defecation. It is different from diarrhea because the former is only more frequent than normal, but the fecal traits are normal or not changed much. The feeling of defecation is not good enough after the defecation, but there is no fecal discharge or only a small amount of mucus between the feces, so the patient often does not agree. The majority of the blood in the stool of cancer patients is not much, the color is bright red, and it can be mixed with feces, which is often ignored by the patients and doctors. When the cancer develops, the constipation can occur when the intestine is infiltrated for one week. The difficulty of defecation, the thinning of the stool, and the symptoms of chronic obstruction such as lower abdominal pain and discomfort, some patients may have diarrhea and constipation before.
When a cancer patient penetrates the intestinal wall, infiltrates the prostate or the bladder, there may be symptoms such as frequent urination, urgency, dysuria, hematuria, dysuria or dripping. If the cancer penetrates the bladder, it may form a rectal bladder fistula. Gas escape and fecal matter can occur in the urine. Female rectal anterior wall cancer can penetrate the posterior wall of the vagina and penetrate the posterior wall of the vagina, causing an increase in vaginal discharge; if the posterior wall of the vagina penetrates, it forms a rectal vaginal fistula, and vaginal and bloody secretion occurs in the vagina. The posterior rectal cancer of the rectum penetrates the intestinal wall and infiltrates the pelvic wall, the tibia and the sacral plexus. Causes pain in the tail and a feeling of bulging. These symptoms are advanced manifestations, patients often accompanied by systemic symptoms such as fatigue, weight loss, anemia, weight loss.
When the cancer is involved in the anal canal or around the anus, in addition to the manifestation of blood in the stool, the patient often complains of anal pain and a mass protruding in the anus. Most patients are accompanied by frequent and defecation. Defecation incontinence can occur when a cancer invades the anal sphincter. Since the lymphatic drainage of the anal canal can firstly go to the inguinal lymph nodes, when lymphatic metastasis occurs, swollen, hard lymph nodes can appear in the inguinal region, and then merge into a mass. In addition, lymphatic drainage of the anal canal can be along the blood vessels in the rectum to the paravascular lymph nodes in the iliac crest and in the obturator. When lymph node metastasis infiltrates the obturator nerve, the patient may develop intractable perineal pain and radiate to the inside of the thigh. These are all late manifestations of cancer.
Rectal cancer related examination
(1) Changes in bowel habits, bloody stools, pus and bloody stools, urgency, constipation, diarrhea, etc.
(B) the stool gradually thinning in the late stage, there is defecation obstruction weight loss or even dyscrasia.
(C) rectal examination: is the necessary examination steps for the diagnosis of rectal cancer. About 80% of rectal cancer patients can be diagnosed by the natural rectal examination at the time of treatment and found to be able to reach the hard and uneven bumps; late reachable intestinal stenosis The fixed fingertips of the mass are seen as dirty pus containing feces.
(D) rectal microscopy: can see the size and shape of the tumor and can directly take the interventional tissue for disease examination.
Diagnosis
Differential diagnosis
Differential diagnosis of fecal column deformation:
1, colonic inflammatory diseases: such as intestinal tuberculosis, schistosomiasis, granuloma, amoebic granuloma, ulcerative colitis and colon polyposis. The clinical identification points are the length of the disease, the feces are checked for parasites, and the morphology and extent of the lesions seen in the barium enema examination. The most reliable identification is biopsy by colonoscopy.
2, abscess around the appendix: can be misdiagnosed as cecal cancer (colon cancer), but the blood of the disease in the white sausage and neutrophils increased, no anemia, weight loss and other cachexia, for barium enema examination can be a clear diagnosis.
3, other tumors of the colon: such as colorectal carcinoid, tumors are asymptomatic, the tumor can be ruptured when grown up, appearing like the symptoms of colon adenocarcinoma; malignant lymphoma originating in the colon, the shape of the lesion is diverse It is often indistinguishable from colon cancer. All should be identified by tissue smear biopsy.
The main basis for the diagnosis of rectal cancer
(1) Changes in bowel habits and nature.
(2) rectal examination and rectal examination well-known in the rectum, the endoplasmic hard irregular mass of the tissue taken deep into the disease can be confirmed.
Eating beneficial foods to prevent cancer may reduce the incidence of cancer itching by 30%-60%. Alkaline foods such as fruits, vegetables and whole grains are essential in the daily diet and are very important.
The diagnosis of this disease is not very difficult, about 75% of patients can only find the lesion through simple rectal examination. However, the rate of misdiagnosis of rectal cancer is high, mainly because the doctor ignored the rectal examination. Rectal cancer is a common malignant tumor of the digestive tract, but it is easily misdiagnosed. The clinician should routinely perform digital rectal examination and sigmoidoscopy for each patient with hemorrhage, rectal irritation or stool habit change, and early detection of the lesion.
