Colon cancer is a tumor arising from the malignant transformation of colonic mucosal epithelial cells. Early symptoms lack specificity; common manifestations include abdominal pain, blood in the stool, and changes in bowel habits.Symptoms differ between cancers of the right colon and the left colon.
Global incidence of colon cancer by country
Colon cancer is one of the most common malignant tumors worldwide. In my country, its incidence is rising year by year, ranking between third and fifth among all malignant tumors.It predominantly affects individuals over the age of 40, with higher incidence rates in men than in women.It is closely associated with high-fat, low-fiber diets, obesity, physical inactivity, and genetic factors.
Symptoms associated with colon cancer stages
1.Early symptoms of colon cancer
The tumor is confined to the colonic mucosa; there are usually no obvious symptoms, though mild abdominal discomfort, changes in bowel habits, or a positive fecal occult blood test may occur. It is easily overlooked.
2.Symptoms of intermediate-stage colon cancer
Symptoms include worsening abdominal pain, bloody or mucus-laden stools, and significant changes in bowel habits; right-sided colon cancer may present with a palpable abdominal mass, accompanied by anemia and weight loss.
3.Symptoms of advanced colon cancer
Tumor causing intestinal obstruction, presenting with severe abdominal pain, abdominal distension, and cessation of bowel movements and flatus, accompanied by severe weight loss, cachexia, and symptoms of distant metastasis.
When to Seek Medical Attention
Early signs of colon cancer include abdominal pain, blood in the stool, changes in bowel habits, and abdominal masses.Please consult a doctor via the "Chat with a Doctor" feature for early detection.During the online consultation, the doctor will ask about your symptoms and family history, and guide you through the process of undergoing a colonoscopy.
Staging of colon cancer
Stage 0 colon cancer
Cancer cells are confined to the colonic mucosal epithelium; this is classified as carcinoma in situ. It is often asymptomatic and may be incidentally detected during colonoscopy screening.
Stage I colon cancer
The tumor is confined to the intestinal wall without lymph node metastasis; mild abdominal pain or changes in bowel habits may occur.
Stage II colon cancer
Tumor penetrates the bowel wall without lymph node metastasis; symptoms include bloody stools, abdominal pain, and narrowing of the stool.
Stage III colon cancer
The tumor is associated with regional lymph node metastasis, increased bloody stools, intestinal obstruction, and significant emaciation.
Stage IV colon cancer
Distant metastasis to the liver, lungs, and bones occurs, leading to persistent severe pain, cachexia, and multiple organ failure.
Detailed Overview of Colon Cancer Symptoms
1.Abdominal pain and distension
Right-sided colon cancer typically presents with dull or aching pain, whereas left-sided colon cancer often presents with cramping pain.Abdominal distension and pain occur when the tumor causes narrowing of the intestinal lumen, worsening after eating.
2.Bloody and mucous stools
Rectal bleeding is typically dark red and mixed with stool, often accompanied by mucus; bleeding from right-sided colon cancer may manifest as melena (black, tarry stools) or a positive fecal occult blood test.
3.Change in bowel habits
Increased or decreased bowel movement frequency, alternating constipation and diarrhea, narrowing or deformation of the stool, and a marked sensation of tenesmus.
4.Abdominal mass
A hard mass with an uneven surface and tenderness palpable in the right lower quadrant is a characteristic presentation of right-sided colon cancer.
5.Anemia and fatigue
Right-sided colon cancer often causes iron-deficiency anemia due to chronic blood loss, manifesting as pallor, fatigue, dizziness, and palpitations; these may be the initial symptoms.
6.Symptoms of intestinal obstruction
Left-sided colon cancer is prone to causing luminal narrowing and obstruction, presenting with severe abdominal pain, abdominal distension, vomiting, and cessation of passing stool and gas.
7.Rapid weight loss
Significant short-term weight loss due to tumor-induced metabolic consumption and reduced food intake, accompanied by fatigue and loss of appetite; progresses to a cachectic state in the advanced stage.
8.Change in stool shape
The tumor occupies space within the intestinal lumen, causing the stool to become thin, flattened, or grooved; defecation becomes difficult, and the stool narrows to a pencil-like shape.
9.Dyspepsia
Right-sided colon cancer is often accompanied by gastrointestinal symptoms such as dyspepsia, abdominal distension, nausea, and loss of appetite, making it prone to misdiagnosis as a gastrointestinal functional disorder.
Conclusion
Early symptoms of colon cancer are often atypical and easily overlooked;regular colonoscopy is key to early detection. A high-fiber diet, regular exercise, and quitting smoking or limiting alcohol intake can help reduce the risk of developing the disease.
