An article published in the September issue of The Journal of Nuclear Medicine finds that over 50% of colorectal cancer patients’ treatments were changed after receiving positron emission tomography (PET) imagery analysis. In the largest multi-institutional study of its kind to date, the results highlight the ability of PET to change disease management of individuals with suspected recurrent colorectal cancer.

Colorectal cancer is the fourth most common cancer in the United States and will kill about 50,000 Americans in 2008, according to the National Cancer Institute. About 108,000 new cases of colon cancer and more than 40,000 cases of rectal cancer were diagnosed in 2007 alone. Positron emission tomography (PET) is a nuclear medicine imaging technique that results in a 3-D image of a bodily process or function. Andrew M. Scott, M.D. (Director, Center for PET and the Ludwig Institute for Cancer Research, Austin Hospital, Melbourne, Australia) and colleagues sought to determine the role that PET could play in managing care of individuals with colorectal cancer.

At four sites throughout Australia, researchers gathered 191 patients and divided them into two groups. The first group (Group A) included symptomatic patients with residual structural lesions that were suspicious for recurrent tumor after initial therapy. The second group (Group B) included patients with pulmonary (lung) or hepatic (liver) metastases that could possibly be removed surgically. The patients’ PET results were analyzed and then compared with results from conventional imaging like computed tomography (CT) scans. Patients in both groups were followed for 12 months.

In more than 65% of patient in Group A and about 50% of patients in group B, treating physicians used the PET results to inform the extent and progression of disease and changed the planned management. In addition, the researchers located other disease sites in 48% of group A patients and in 44% of group B patients. This valuable prognostic data allowed physicians to further stratify patients into curative or palliative groups.

“Designed with an evidence-based approach, this study confirmed the important role PET plays in the decision-making process of patients with colorectal cancer and the impact of PET on both the management and outcome of disease,” said Dr. Scott. “These results are compelling and indicate that PET should be made more widely available to patients.”

The researcher added that, “PET was able to identify those patients who had potential for long-term, progression-free survival and even a potential cure. Just as important, it identified those patients with aggressive disease, enabling them to avoid unnecessary treatment, such as surgery.”

According to data collected by the U.S. National Oncologic PET Registry (NOPR), PET results have been used in the United States to change clinicians’ decisions in the treatment and care of more than one in three cancer patients.

“This data should encourage molecular imaging practitioners to engage with referring physicians early in the process of cancer treatment,” concludes Scott. “It is clear that PET had a significant impact for these patients and could be an indispensable part of the standards of care for oncologists.”

PET Changes Management and Improves Prognostic Stratification in Patients with Recurrent Colorectal Cancer: Results of a Multicenter Prospective Study
Andrew M. Scott, Dishan H. Gunawardana, Amanda J. Byrne, Ben Kelley, John G. Stuckey, Jayne E. Ramshaw, Michael J. Fulham
The Journal of Nuclear Medicine (2008).
Click Here to View Journal Website

Written by: Peter M Crosta