Dear Friends,

Welcome to the fifth annual Gastrointestinal Cancers Symposium. It is exciting to see the new research on cancer prevention, screening, and treatment presented at this meeting each year. To help inform people about progress in cancer, ASCO publishes Cancer Advances, a series of consumer information resources. Cancer Advances: News from the Gastrointestinal Cancers Symposium provides the latest information about high-quality cancer care, cancer screening, and personalized medicine for gastrointestinal cancers. The information in this issue was presented at the 2008 Gastrointestinal Cancers Symposium held in Orlando, Florida from January 25-27, 2008. For additional information about cancers of the gastrointestinal system, please visit ASCO's patient website, People Living With Cancer (www.plwc.org).

Sincerely,

Nancy Davidson, MD
ASCO President

An analysis of data from people diagnosed with colorectal cancer shows that those who are uninsured or covered by Medicaid are more likely to be diagnosed with a more advanced stage of colorectal cancer than those with private insurance or Medicare. Stage is a way of describing a cancer. The chance of successful treatment is better when cancer is diagnosed at an earlier stage (such as stage I) than a more advanced stage (stage III and IV).

The study, by the American Cancer Society (ACS), used the National Cancer Database (NCDB) to analyze data from 493,419 people diagnosed with colorectal cancer between 1998 and 2004. The NCDB is a registry sponsored by ACS and the American College of Surgeons that includes about 70% of people diagnosed with cancer in the United States. Insurance coverage for the patients used in the analysis was similar to the overall U.S. population, with approximately 63% covered by Medicare, 32% covered by private insurance, 2% covered by Medicaid, and 2% uninsured.

The results showed that people not covered by health insurance were nearly twice as likely to be diagnosed with stage II colorectal cancer than stage I cancer, compared with people covered by private insurance or Medicare, and twice as likely to be diagnosed with stage III or IV colorectal cancer than those with private insurance or Medicare. For people covered by Medicaid, the likelihood of being diagnosed with a more advanced stage of colorectal cancer was 1.4 times greater for stage II and 1.5 times greater for stage III or IV, when compared with people covered by private insurance or Medicare.

Previous smaller studies have shown a similar connection between insurance and cancer diagnosis, and other studies have shown that having Medicaid is associated with barriers to care, including longer waits for appointments and doctors who do not accept Medicaid patients.

"This study underscores the importance of having adequate insurance coverage. Access to care increases the likelihood of detecting colorectal cancer at an earlier stage. At the same time, we need to develop colorectal cancer screening programs for people who have no insurance or come from low-income households," said Michael T. Halpern, MD, PhD, Strategic Director of Health Services Research at ACS and the study’s lead author.

What this means for patients

Lack of insurance or limited insurance is a barrier for many patients. It is important for patients to talk with a doctor about colorectal cancer screening, including what tests are covered by their health insurance, and the names of organizations that may be able to provide free or low-cost colorectal cancer screening. Regular screening can often detect colorectal cancer earlier when there is a better chance of successful treatment.

Research led by Johns Hopkins University in collaboration with the University of Pittsburgh shows that colon cancer-specific antigen-2 (CCSA-2) may be an accurate indicator of colorectal cancer. CCSA-2 is a tumor marker (a substance found in a person's blood, urine, or body tissue that may indicate an abnormal process in the body; also called a biomarker) that can be measured with a blood test.

In this study, the researchers analyzed 135 blood samples from patients who had undergone colonoscopies. A colonoscopy is a screening test for colorectal cancer that allows doctors to look inside the colon and rectum for polyps (an abnormal growth that may be precancerous; a higher-risk polyp is called an adenoma) or cancer using a colonoscope (lighted tube). The patients were diagnosed as normal (24%), having potentially precancerous growths (polyps: 19%; nonadvanced adenomas: 29%; advanced adenomas: 14%), or colorectal cancer (14%). A control group of 125 people, made up of individuals with noncancerous conditions or other types of cancer, was also included.

The CCSA-2 test had an overall specificity of about 80% (meaning that about 20% of positive results indicated that the samples were cancerous when there was no cancer) and a sensitivity of 91% (meaning that 9% of cancer cases were missed). The researchers also noted that higher levels of CCSA-2 in the blood correlated with larger precancerous growths, and the highest levels of CCSA-2 indicated colorectal cancer. So, the researchers could distinguish patients who had colorectal cancer or advanced adenomas from those with low-risk polyps or normal colons.

"With CCSA-2, we've found a biomarker that not only better detects the presence of colorectal cancer, but also may accurately indicate whether a patient has a high-risk, precancerous condition," said Eddy S. Leman, PhD, Instructor, Department of Urology at Johns Hopkins Hospital in Baltimore, Maryland.

What This Means for Patients

The goal of this research was to find an accurate, simple, and noninvasive method for the early detection of colon cancer. Although this study is promising, the test needs to be repeated with a larger group of patients at more research institutions and is not available for colorectal cancer screening at this time. Many health organizations recommend that men and women be screened for colorectal cancer beginning at age 50, or earlier if there is a strong family history of colorectal cancer or polyps. For more information on colorectal cancer screening, talk with your doctor.

Patients with advanced colorectal cancer benefit from the drug panitumumab (Vectibix) only if their tumors have a normal form, and not a mutated (changed) form, of the KRAS gene, a new study shows. About 30% to 50% of colorectal cancers have mutations in the KRAS gene.

In this study, the researchers analyzed tumor samples from 427 patients for a mutated KRAS gene and found that 43% of samples had a KRAS mutation. The patients had advanced metastatic colorectal cancer and had received all available treatments for colorectal cancer. The patients received either best supportive care (treatment of symptoms of cancer, but not treatment of the cancer itself), or best supportive care and panitumumab, which was given every two weeks.

The cancer did not worsen in patients who received panitumumab and whose tumors had a normal KRAS gene for 12 weeks, compared with seven weeks for patients with tumors with the mutated gene. In the patients receiving best supportive care and no panitumumab, the cancer did not worsen for seven weeks, regardless of the KRAS status. In addition, the tumors shrank in 17% of patients and did not grow bigger in 34% of patients who received panitumumab and had tumors with a normal KRAS gene. In the patients with a mutated KRAS gene who received panitumumab, the tumors did not shrink in any of the patients and did not grow bigger in 12% of the patients.

Panitumumab is a monoclonal antibody (a substance made in the laboratory that recognizes and then attaches to specific proteins on the outside of cancer cells) approved by the U.S. Food and Drug Administration to treat metastatic colorectal cancer when other treatments have stopped working. The most common side effect of panitumumab was a rash, which went away once treatment was stopped.

The study was conducted by researchers from the academic medical centers of Ghent University Hospital and University Hospital Gasthuisberg in Belgium and Ospedale Niguarda Ca' Granda in Italy and Amgen scientists.

What This Means for Patients

"By testing for KRAS mutations, doctors may now be able to identify which patients will most likely benefit from panitumumab treatment," said the lead author, Rafael Amado, MD, Executive Director, Oncology Therapeutics at Amgen, which manufactures and markets the drug.