BIRMINGHAM, AL — UAB researchers have found a better way to predict a lung cancer patient’s chance of survival and odds of the disease’s recurrence. The technique could serve as a supplement to the current cancer-staging system and may address some of its shortcomings.

Robert J. Cerfolio, M.D., associate professor of surgery and chief of thoracic surgery at the University of Alabama at Birmingham (UAB), and colleagues published their findings in the July issue of The Journal of Thoracic and Cardiovascular Surgery.

The study compares the predictive advantage of using a value called the maximum standard uptake value (maxSUV), which is calculated when patients undergo positron emission tomography (PET) scanning. The maxSUV was compared to the standard TNM cancer staging system, the world-wide gold-standard for describing the extent or stage of cancer growth.

“The maximum standard uptake value measures the tumor cell’s affinity for glucose, which, in turn, provides important metabolic or biological information about how active a cancer is, how aggressive it is in a particular patient,” Cerfolio said. “By combining this biological information with anatomical and structural information gleaned from the CT phase of an integrated PET/CT, we obtain a better understanding of tumor characteristics, how fast it may spread to lymph nodes or even to other distant sites, and this may help improve our therapy.

“When we look at the metabolic activity of a tumor, it gives us, in a sense, a chemical picture of how aggressive the cancer cells are and how voracious their appetite is for glucose. Armed with that knowledge, we may be able to provide more effective treatment.”

The TNM system (which stands for tumor, lymph node and metastases), uses information obtained from biopsies and various imaging studies such as chest X-rays, CT scans, bone scans, ultrasounds or MRI to determine the physical location of a tumor, its physical size and whether it has spread to surrounding lymph nodes and/or traveled to other areas of the body. Treatment options — whether surgery, chemotherapy, radiation or a combination — then are based on the determined TNM clinical stage of the cancer.

“Right now, clinicians spend a significant amount of time, money and effort performing various tests to assess the stage,” Cerfolio said. “Yet even after carefully determining the clinical staging — which is a guess of what the real stage is — there are many inaccuracies when compared to the actual pathological stage that is determined after the areas of cancer are biopsied or removed.

“Even more frustrating,” he added, “in those patients for whom we correctly gauge the extent of cancer and surgically remove all of their visible cancer, those with early stage 1a still only have a 60 to 70 percent chance of surviving five years. Thus, the cancers often have micrometastatic disease that we can not detect, which must be circulating in the bloodstream.

“The maxSUV information gathered from PET scan may provide an important supplement to help guide the decision for post-operative or even pre-operative chemotherapy. This is missing in the current anatomic staging system that only provides location and size information.”

In this prospective study of 315 patients, those with high standard uptake values were more likely to have cancer cells that under the microscope appeared to be aggressive (called poorly differentiated tumors), have cancer that spread to the lymph nodes even if undetected by CT scan, to have a higher stage of cancer, to have a worse prognosis, and were less likely to be able to have their entire cancer completely removed by surgery because of undetected spread not known until the time of surgery.

When researchers divided patients into specific stages and then categorized them as either those with higher than normal standard uptake values or those with normal or low values, it became even clearer the maximum SUV was the best predictor of disease-free survival.

Survival-specific analysis showed patients with stage Ib and stage II disease with a maxSUV greater than average values for the respective stages had a lower disease-free survival at four years. The actual four-year survival for patients with stage Ib non-small cell lung cancer was 80 percent for the low value group versus 66 percent for the high value group; for stage II disease it was 64 percent versus 32 percent; and for stage IIIa disease, it was 64 percent versus 16 percent. In general, the higher the number of the stage, the more progressed the disease.

Cerfolio said he and his colleagues believe that although the findings need further corroboration by larger, multi-institution clinical trials, “these provocative data could have significant clinical implications, and change how we decide how to treat patients and the way we report a patient’s clinical or pathologic stage.”

Cerfolio added the methodology also may be beneficial for staging, predicting and guiding treatment strategies for other types of cancer.

More than 90,000 men and 79,000 women in the United States are diagnosed each year with lung cancer and an estimated 163,500 deaths from lung cancer are expected in 2005, according to the National Cancer Institute.

EDITOR’S NOTE: We are the University of Alabama at Birmingham. Please use UAB on second reference. We are not to be confused with the University of Alabama, which is a separate, independent campus.