March is Colorectal Cancer Awareness Month
What You Need to Know
- Colorectal cancer refers to any cancer in the colon or rectum.
- Polyps are usually benign growths that form in the colon and rectum. These polyps may progress into cancer if left untreated.
- If you have polyps, they may develop into cancer, so your doctor will want to monitor you regularly.
- Some forms of colorectal cancer are hereditary; if colorectal cancer runs in your family, you should undergo regular colonoscopies.
- Subcategories of colorectal cancer include: hereditary colorectal cancer, hereditary nonpolyposis colorectal cancer and sporadic (nonhereditary) colorectal cancer.
Read a more in-depth article about colorectal cancer, written by Johns Hopkins gastroenterologists, which details the anatomical description of the causes of colorectal cancer.
How common is colorectal cancer?
Colorectal cancer is a major cause of death in western societies and in countries with diets high in animal fats and protein and low in fiber. It ranks as the third most common cancer in the United States below breast cancer and lung cancer.
About 130,000 new cases are diagnosed each year in North America, and 56,000 die annually from this disease. Epidemiological studies have shown an increase in the incidence of colorectal cancer in both whites and non-whites with African Americans having a substantially increased risk of dying.
Is colon cancer preventable?
Colon cancer screening is one way that everyone can improve his or her chances against colon cancer. Early detection is essential to improve survival, and screening is vital to prevention and should be a part of routine care.
Current recommendations for colorectal cancer screening for asymptomatic average-risk individuals 50 years of age or older include: annual fecal occult blood test and sigmoidoscopy every five years, or colonoscopy every 10 years or double-contrast barium enema every 10 years.
High-risk individuals (those with previous colon cancer, inflammatory bowel disease, or history of colorectal polyps) require a colonoscopy every two to five years depending on the individual. People with a family history of colorectal cancer should undergo screening colonoscopy starting at age 40, or 10 years before the youngest case in the family, which ver comes first.
Is colon cancer inherited?
Environmental, dietary and genetic factors are thought to play a role in the development of colorectal cancer. The most common risk factor for colorectal cancer is a positive family history. Approximately 20 percent of colorectal cancer cases are originate in those with a family historiy.
In fact, first-degree relatives of persons with colon cancer have been found to have a two- to three-fold increase risk of colorectal cancer compared with controls. About 5 percent of patients with colorectal cancer have clearly defined inherited syndromes such as familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). These syndromes are well described, both genetically and phenotypically, and are characterized by dominant inheritance, high penetrance, and high risk of colorectal cancer.
In cases of sporadic colorectal cancers, where no family history exists, an acquired point mutation on chromosome 5q21 has been identified (MCC gene). Oncogenes C-myc and Ras have been associated with colorectal cancers showing elevated C-myc levels in most cases of colorectal cancer and Ras point mutations found to be an early event in transformation of premalignant adenomas to colorectal cancers.
Advancements in Cancer Research
DNA Shed by Tumors Show Promise for Non-Invasive Screening and Prognosis
Cancerous tumors shed fragments of DNA into the bloodstream. Researchers have determined how to identify those fragments in blood samples, a discovery with major implications for a non-invasive, early detection method.
The Genetics of Gastric Cancer
Everyone agrees that early detection is a key to beating cancer. Discover how scientists like are using deep sequencing -- where they look at the entire genome at once -- to work on the genetics in the early stages of precancer.
Small Molecule Shows Promise as Anti-Cancer Therapy
Transcription pathways are the means by which certain proteins that direct cell division are put into action by cells. Uncontrolled cell division is a hallmark of cancer -- but Johns Hopkins scientists say a previously known but little studied chemical compound targets and disrupts tumor cell division and prevents growth of advanced cancer cells.
Find a Colorectal Cancer Specialist
The Johns Hopkins Division of Gastroenterology and Hepatology offers services and procedures at a number of locations throughout the greater Baltimore region.