Colon And Rectal Cancer Flashcards
What is colorectal cancer?
Colorectal cancer starts in the colon or rectum, depending on the site of origin.
What is the global ranking of colorectal cancer in terms of commonality and mortality?
It is the third most common cancer worldwide and the second leading cause of cancer death.
What is the 5-year survival rate for colorectal cancer?
Approximately 55%.
What percentage of colorectal cancers are sporadic?
Nearly 70% of cases.
What hereditary syndromes are associated with colorectal cancer?
Lynch syndrome (HNPCC) and Familial Adenomatous Polyposis (FAP).
What is the adenoma-carcinoma sequence?
The progression of normal colonic mucosa to adenoma (polyp) and then to invasive adenocarcinoma.
What dietary factors increase the risk of colorectal cancer?
High intake of red and processed meat, low fiber diet, high saturated fat consumption.
What lifestyle factors contribute to colorectal cancer risk?
Tobacco smoking, excessive alcohol consumption, physical inactivity, and obesity.
What anatomical structure marks the beginning of the colon?
The cecum, where the terminal ileum enters.
How long is the colon?
Approximately 1.6 meters.
What arteries supply blood to the colon?
Superior mesenteric and inferior mesenteric arteries.
Which artery supplies the rectum?
Branches of the internal iliac artery.
What is the primary venous drainage of the colon and rectum?
Veins running parallel to the arteries, draining into the portal system.
Which nerve fibers innervate the colon and rectum?
Parasympathetic and sympathetic fibers from the lower thoracic and lumbosacral spinal cord.
What is the most common histological type of colorectal cancer?
Adenocarcinoma.
Which gene mutations are involved in colorectal cancer?
APC, KRAS, TP53, PTEN, and TGFβ mutations.
What are the three major molecular pathways in colorectal cancer?
Chromosomal Instability (CIN), Microsatellite Instability (MSI), CpG Island Methylator Phenotype (CIMP).
Which oncogene is involved in colorectal tumorigenesis?
RAS proteins encode small GTP hydrolases that function as a growth switch.
What role does the APC gene play in colorectal cancer?
Mutation of the APC gene initiates the adenoma-carcinoma sequence.
Which dietary factors are protective against colorectal cancer?
High fiber diet, vitamin D, and calcium intake.
What are the typical symptoms of right-sided colon cancer?
Abdominal pain, iron-deficiency anemia, melena, and a palpable mass in the right iliac fossa.
What are the symptoms of left-sided colon cancer?
Abdominal pain, constipation, change in bowel habit, rectal bleeding, tenesmus, and progressive weight loss.
What is the gold standard investigation for colorectal cancer?
Colonoscopy with biopsy.
What tumor marker is used to monitor colorectal cancer?
Carcinoembryonic Antigen (CEA).
Which imaging studies are used for tumor staging in colorectal cancer?
CT scan (chest, abdomen, pelvis), MRI rectum, and Endo-anal ultrasound.
What is the TNM staging system used for?
It classifies colorectal cancer based on tumor size (T), nodal involvement (N), and metastasis (M).
What is the treatment for stage I-III colorectal cancer?
Surgical resection with curative intent.
What is the treatment for stage IV colorectal cancer?
Chemotherapy, targeted therapy, and palliative surgery if necessary.
What is the role of adjuvant chemotherapy in colorectal cancer?
Used in stage III disease to reduce recurrence risk.
Which chemotherapy drugs are commonly used for colorectal cancer?
Capecitabine, 5-Fluorouracil (5-FU), Irinotecan, Oxaliplatin.
What is regional chemotherapy for colorectal cancer?
Direct administration of chemotherapy into the hepatic artery to treat liver metastases.
Which targeted therapies are used for metastatic colorectal cancer?
Bevacizumab, Cetuximab, Panitumumab, and Encorafenib.
Which immunotherapy drugs are used for colorectal cancer?
Ipilimumab, Nivolumab, Pembrolizumab.
What surgical procedure is used to remove colorectal polyps?
Polypectomy via colonoscopy.
What is total mesorectal excision (TME)?
A precise surgical technique used for rectal cancer to remove the rectum and surrounding lymph nodes.
What is an anastomosis in colorectal surgery?
Reconnection of the bowel ends after resection.
When is a colostomy required in colorectal cancer treatment?
When bowel continuity cannot be restored after resection.
What is radiofrequency ablation used for in colorectal cancer?
It destroys cancer cells using heat, often for liver metastases.
What is cryosurgery in colorectal cancer treatment?
A technique that freezes and destroys cancer cells.
What is neoadjuvant therapy?
Chemotherapy or radiation given before surgery to shrink the tumor.
What is metastatectomy?
Surgical removal of cancerous deposits in organs such as the liver or lungs.
What is the most common site for colorectal cancer metastasis?
The liver.
What is the recommended follow-up after colorectal cancer treatment?
Regular colonoscopies, imaging, and CEA monitoring.
What lifestyle changes help prevent colorectal cancer?
Increased fiber intake, reduced red meat consumption, regular exercise, and avoiding smoking and alcohol.
What pharmacologic agents can help in colorectal cancer prevention?
Aspirin and NSAIDs in high-risk individuals.
What is the significance of microsatellite instability (MSI) in colorectal cancer?
It predicts response to immunotherapy and prognosis.
What is the role of the CpG Island Methylator Phenotype (CIMP) pathway?
Hypermethylation of tumor suppressor genes, contributing to colorectal cancer.
What is the survival rate of colorectal cancer with early detection?
Significantly higher, as early-stage disease is highly curable.
