Colon cancer is a major component of colorectal cancer, with an incidence rate that has been rising in recent years.It is closely associated with dietary habits, obesity, and physical inactivity.While the prognosis for early-stage colon cancer is favorable, most patients are diagnosed at an intermediate or advanced stage.
Diagnosis based on colon cancer stages
1.Early diagnosis of colon cancer
The tumor is confined to the colonic mucosa; it is often asymptomatic.Colonoscopy screening reveals polyps or superficial lesions, confirmed by biopsy.A positive fecal occult blood test indicates the need for further examination.
2.Diagnosis of intermediate-stage colon cancer
Symptoms include bloody stools, abdominal pain, and changes in bowel habits.Colonoscopy reveals cauliflower-like masses or ulcerative lesions; contrast-enhanced CT assesses the depth of tumor invasion and regional lymph node metastasis.
3.Diagnosis of advanced colon cancer
Tumor penetrates the bowel wall or metastasizes distantly to the liver or lungs.Whole-body CT and PET-CT assess the extent of metastasis; laparoscopic exploration clarifies staging and guides the comprehensive treatment plan.
If colon cancer is not diagnosed in time, the tumor may invade deeper tissues and metastasize to distant sites, resulting in the loss of the opportunity for curative surgery and a significantly poorer prognosis.
When to Seek Medical Attention
Early signs of colon cancer include blood in the stool, abdominal pain, 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.
Basis for colon cancer diagnosis
1.Colonoscopy
Colonoscopy is the preferred method for diagnosing colon cancer; it enables direct observation of tumor morphology, location, and extent, as well as tissue sampling for pathological examination, serving as the gold standard for definitive diagnosis.
2.Pathological tissue biopsy
Endoscopic biopsy or resection of the lesion is performed for pathological examination to determine the histological type, degree of differentiation, and MMR/MSI status, thereby guiding decisions regarding immunotherapy.
3.Abdominal CT scan
Contrast-enhanced CT evaluates the location and extent of the primary tumor, as well as regional lymph node and distant organ metastases, making it the preferred imaging modality for colon cancer staging.
4.Tumor marker testing
Measurement of serum CEA and CA19-9 levels to assist in diagnosis, treatment efficacy assessment, and postoperative follow-up monitoring for recurrence.
5.Chest CT scan
Contrast-enhanced chest CT is used to rule out pulmonary metastasis and is a routine examination for initial staging and follow-up.
6.Abdominal ultrasound
Ultrasound can assess the liver for metastatic lesions; ultrasound-guided needle biopsy can be performed on suspicious hepatic lesions to obtain a pathological diagnosis.
7.Fecal occult blood test
Fecal immunochemical testing (FIT) is a common method for colon cancer screening; a positive result requires further colonoscopy.
8.Abdominal MRI
MRI serves as a valuable adjunct to CT for assessing the number, size, and distribution of hepatic metastases, thereby guiding decisions regarding local treatment.
9.Genetic testing analysis
Detection of RAS and BRAF gene status as well as MSI/MMR status guides the selection of targeted therapy and immunotherapy; this is a mandatory test for metastatic colon cancer.
Daily Self-Check
5. Individuals over the age of 50 should undergo regular colonoscopy screening.Medical attention should be sought promptly if symptoms such as bloody stools, changes in bowel habits, or abdominal pain occur.Those with a family history should begin screening earlier, at age 40.
Conclusion
Early diagnosis of colon cancer is crucial for improving cure rates.Colonoscopy is the gold standard for diagnosis, and regular screening is recommended for high-risk groups.
