Colorectal Cancer

Colorectal Cancer

Dramatic progress has been made in the prevention, detection and treatment of colorectal cancer. The five-year survival rate for early-stage colorectal cancer is now 90 percent, and overall mortality for colorectal cancer in the United States has fallen by 40 percent since the 1970s.

Recently, colorectal cancer has served as a proving ground for molecularly targeted therapies. Use of these treatments to attack tumors with a specific genetic profile can add many months to the lives of some patients with incurable disease. Researchers hope that by developing additional targeted drugs, and by combining them in new ways, they can continue to extend lives and cure more patients.

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2016

Colorectal tumor location affects prognosis, may inform treatment choice

Colorectal tumor location affects prognosis, may inform treatment choice

Research uncovers an unexpected factor may help explain why some patients with colorectal cancer do better than others: tumor location in the body. According to an analysis of data from a large clinical trial, patients with advanced colorectal cancer live longer if the cancer begins on the left side of the colon rather than on the right side. Further research suggested that the efficacy of two standard targeted treatments, bevacizumab (Avastin) and cetuximab (Erbitux), differs with respect to the side of the body where cancer began (although previous trials found that both treatments – in combination with chemotherapy - yield similar survival). For patients with left sided tumors, a cetuximab-based regimen was more effective than bevacizumab with chemotherapy, whereas patients with right-sided tumors derived limited benefit from either regimen.

2012

Two new targeted drugs available

2009

New gene assay predicts risk of colon cancer recurrence

New gene assay predicts risk of colon cancer recurrence

For the first time, doctors are able to use a genetic test to predict the risk of recurrence for patients with stage II colon cancer (cancer with very little to no spread within the wall of the colon). This improves their ability to determine which patients should receive additional chemotherapy treatments, sparing those with a lower risk of recurrence from unnecessary chemotherapy and related side effects.

Adequate bowel preparation essential for effective colonoscopy

Adequate bowel preparation essential for effective colonoscopy

Researchers show that proper bowel cleansing is essential to ensure the quality of results provided by routine colonoscopies. This cleansing includes adhering to a clear liquid diet and taking a bowel prep (involving a laxative or enema) the day before the procedure. Incomplete preparation is a fairly common problem, due to the dietary restrictions and the potential inconvenience involved.

Patients with advanced, incurable colon cancer do not need to undergo surgery on their primary colon tumor

Patients with advanced, incurable colon cancer do not need to undergo surgery on their primary colon tumor

Researchers show that patients who are newly diagnosed with advanced incurable disease do not need to undergo surgery on the primary tumor in their colon, unless that tumor causes significant complications. Although surgery was previously standard for all patients, investigators show that chemotherapy alone was sufficient at helping to control the patient's tumor so that it did not cause complications or affect their quality of life.

2008

Molecular markers predict effectiveness of widely-used chemotherapy drug and prognosis for early-stage colon cancer

Molecular markers predict effectiveness of widely-used chemotherapy drug and prognosis for early-stage colon cancer

An analysis of data from multiple studies shows that "mismatch-repair status" – the cancer cell's ability to correct genetic damage – can help predict prognosis in patients with stage II and III colon cancers and whether they will benefit from 5-fluorouracil, a commonly used chemotherapy drug. According to this research, patients with cells that are unable to repair certain DNA damage (called MSI-High) are less likely to benefit from 5-fluorouracil. However, these patients are less likely to experience a recurrence following successful treatment with other therapies, and therefore are likely to have a better long-term outcome.

Flat colon growths more likely to be cancerous than more obvious ones

2007

Lymph node sampling for staging is refined

Lymph node sampling for staging is refined

Researchers determine that at least 12 abdominal lymph nodes need to be removed and analyzed during colon cancer surgery to accurately determine the stage of the tumor. This study finds that the more lymph nodes that were sampled, the longer a patient lived on average following therapy. Accurate staging is necessary to identify which patients are at high risk of recurrence and are therefore candidates for adjuvant chemotherapy following surgery.

Diet, exercise reduce risk of colon cancer recurrence

Diet, exercise reduce risk of colon cancer recurrence

Patients who follow a low-fat diet and exercise regularly are found to have a lower risk of colon cancer recurrence after surgery for early-stage disease, demonstrating that lifestyle factors can have a significant impact on cancer recurrence. The results provide patients with new tools for reducing the risk that their cancer will return.

2006

Taking more time to perform colonoscopy increases screening accuracy

2005

Two targeted drugs approved for advanced colon cancer

Two targeted drugs approved for advanced colon cancer

The drugs cetuximab (Erbitux) and panitumumab (Vectibix) are approved to treat colon cancer that has spread to other parts of the body (metastatic disease). These drugs attack tumors that express the epidermal growth factor receptor (EGFR) protein, which is involved in cancer cell growth. Later, a coordinated analysis of multiple studies shows that cetuximab and panitumumab are effective only in patients with the normal form of a gene known as KRAS. This discovery helps physicians ensure that the drugs are used only for patients who stand to benefit, while eliminating unnecessary treatment and costs for patients who will not.

Conventional colonoscopy established as optimal screening method

Conventional colonoscopy established as optimal screening method

Two studies show that conventional colonoscopy is better able to detect colon cancer than other, less invasive screening techniques such as "virtual colonoscopy," barium enema or fecal DNA testing. Researchers demonstrate that colonoscopy detects 98 to 99 percent of tumors – about twice as many as virtual colonoscopy (the use of CT scanning to provide a three-dimensional image of the colon) or barium enema. Current medical guidelines state that colonoscopy is the superior colorectal cancer screening tool, but emphasize that some form of screening with any of these tests is better than going without screening.

Right-sided colon cancers present a challenge for colonoscopy

Right-sided colon cancers present a challenge for colonoscopy

Researchers find that undergoing a colonoscopy every 10 years reduces the risk of cancer on the left side of the colon, but not on the right side. Subsequent studies confirm that right-sided colon cancers are more likely than those on the left to be missed during the screening procedure because it is harder to reach the right side of the colon and right-sided lesions may be flat and harder to detect.

2004

FDA approves first "anti-angiogenic" drug, bevacizumab

FDA approves first "anti-angiogenic" drug, bevacizumab

Bevacizumab (Avastin) is the first of a new generation of targeted drugs, called anti-angiogenics, that attack cancer by blocking the growth of blood vessels that tumors needs to grow. First approved to treat colorectal cancer, in 2004, the drug has since become an important treatment for patients with advanced lung, ovarian and kidney cancers, and for certain brain tumors, who have few other effective options.

Chemotherapy and radiation before surgery reduce side effects for rectal cancer patients

Chemotherapy and radiation before surgery reduce side effects for rectal cancer patients

Results from a large clinical study show that giving chemotherapy and radiation therapy before, rather than after, rectal cancer surgery reduces the risk of local recurrence (cancer recurrence in the pelvis, near the original tumor). Survival was similar in both approaches, but because the pre-surgery treatment regimen was more tolerable, it is now the standard approach for treatment of rectal cancer.

Laparoscopic colon cancer surgery effective, better tolerated

Laparoscopic colon cancer surgery effective, better tolerated

A study by researchers at multiple cancer centers finds that laparoscopic surgery to remove colon tumors was as effective as conventional open abdominal surgery, and was associated with shorter hospital stays and less pain after surgery. Laparoscopic surgery involves removing the tumor through multiple small incisions and a telescoping camera device. This less-invasive approach is now widely used.

2003

Aspirin and similar anti-inflammatory medications help reduce colon cancer risk

Aspirin and similar anti-inflammatory medications help reduce colon cancer risk

Two large studies show that taking daily aspirin prevents the development of precancerous colorectal polyps, and a later trial involving another anti-inflammatory drug, celecoxib (Celebrex), reports a similar finding. However, this use of aspirin or similar anti-inflammatory drugs is not yet recommended for cancer prevention among the general public, due to the risk of potentially serious side effects, such as stomach bleeding. Large, randomized studies are currently underway to evaluate the benefit of these drugs in prevention of polyps, second colon cancers and cancer recurrence.

New "FOLFOX" chemotherapy effective for colon cancer

New "FOLFOX" chemotherapy effective for colon cancer

Oxaliplatin (Eloxatin) combined with 5-fluorouracil and leucovorin (a regimen called FOLFOX) is approved to treat advanced colon cancer that has spread despite other treatments. FOLFOX is later approved for stage III colon cancer (cancer involving the nearby lymph nodes) following surgery, after a pivotal trial finds that it increased the time that patients live without their cancer returning (disease-free survival). Longer-term data from the same study found that the combination also extends patients' lives.

First oral chemotherapy drug helps simplify colon cancer treatment

First oral chemotherapy drug helps simplify colon cancer treatment

The FDA approves capecitabine (Xeloda) for patients with advanced (metastatic) colon cancer, and later for patients with stage III colon cancer (cancer with limited spread in the surrounding tissue) who have had surgery to remove the tumor. Capecitabine is a pill version of the widely used intravenous chemotherapy drug 5-fluorouracil that offers comparable effectiveness with a more convenient way for patients to receive their treatment. Recently, capecitabine has been combined with the drug oxaliplatin (Eloxatin) as an initial therapy for metastatic colon cancer and for early-stage colon cancer.

1997

Surgery found to cure some patients with advanced colorectal cancer

Surgery found to cure some patients with advanced colorectal cancer

In general, metastatic cancer is difficult or impossible to treat with surgery because tumor cells have spread throughout the body. But in a 1997 study, researchers find that some colon cancer patients with tumors that have spread to the liver alone can be cured with surgery. In a study of nearly 300 such patients who underwent surgery between 1960 and 1987, about one in four were still alive five years later, and nearly of all of these patients were found to have been essentially cured. A later study finds that use of positron emission tomography, or PET scanning, can identify some liver metastases that would have gone unnoticed before, helping surgeons in the study to achieve a cure rate above 50 percent for patients with metastatic disease.

1996

Irinotecan is approved for advanced colon cancer

Irinotecan is approved for advanced colon cancer

The FDA approves irinotecan (Camptosar), given with the drugs 5-fluorouracil and leucovorin, for patients with advanced colon cancer that has returned despite prior treatment. Irinotecan is the first new chemotherapy drug approved for advanced colon cancer in roughly 40 years. Although prognosis generally remains poor for patients with this stage of cancer (also called metastatic disease), the new drug is shown to improve survival and help preserve quality of life.

1994

New gene tests for hereditary conditions that increase colorectal cancer risk

New gene tests for hereditary conditions that increase colorectal cancer risk

Genetic tests become available for familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, also known as Lynch Syndrome; these inherited disorders are known to increase colorectal cancer risk. The new tests enable physicians to identify people with these conditions and monitor them more closely for cancer or pre-cancerous polyps through regular colonoscopy screenings.

1990

Treatment after surgery increases colorectal cancer survival

Treatment after surgery increases colorectal cancer survival

Doctors begin administering chemotherapy following surgery (adjuvant treatment) to patients with colon and rectal cancer whose disease has spread within the wall of the colon and to nearby lymph nodes (stage III), after clinical trials show that the approach improves survival and significantly reduces the risk of cancer recurrence. Adjuvant therapy becomes a mainstay of colon cancer treatment after a U.S. National Institutes of Health expert panel recommends the approach in 1990. Previously, about half of patients experienced a recurrence of their cancer after surgery, which often led to death. Adjuvant therapy was found to reduce the risk of recurrence and improve survival by about 40 percent.

1985

Minimally invasive approach useful for some rectal cancers

1982

Limited surgery helps rectal cancer patients avoid colostomies

Limited surgery helps rectal cancer patients avoid colostomies

A new procedure called total mesorectal excision emerges as a new standard surgical treatment for many patients with rectal cancer. The procedure involves removing only the cancerous region of the rectum, allowing patients to maintain normal bowel function. Previously, nearly all patients with rectal cancer had to undergo permanent colostomies (elimination of waste through an opening in the abdomen connected to a colostomy bag).

1971

Screening tests for colorectal cancer dramatically reduce deaths

Screening tests for colorectal cancer dramatically reduce deaths

In 1967, the guaiac fecal occult blood test (FOBT) is introduced as a screening test for colorectal cancer, one of the most common forms of cancer. This simple and inexpensive tool detects the presence of blood in stool, a sign that cancerous or precancerous growths (called polyps) may be present. Within the next few years, two new screening techniques – flexible sigmoidoscopy and colonoscopy – enable physicians to examine the colon using a small camera attached to a flexible lighted tube. The widespread use of these approaches leads to better detection of precancerous polyps and early stage cancers that are usually curable with surgery. Over the coming decades, routine screening contributes to major reductions in colorectal cancer mortality – a total decline of more than 40 percent since 1975.

1954

5-FU becomes mainstay of chemotherapy for colorectal cancer

5-FU becomes mainstay of chemotherapy for colorectal cancer

Researchers begin using the chemotherapy drug 5-fluorouracil (5-FU) in patients with advanced colorectal cancer, following promising data on the drug in other cancer types. Over the following decades, researchers continue to refine 5-FU dosing and administration to maximize its effectiveness and manage the often-intense side effects of the drug. 5-FU remains a mainstay of treatment for colorectal cancer and has helped cure thousands of patients when used in combination with other treatments, including radiation, surgery and other chemotherapy drugs.