Imaging improves outlook for lung cancer patients

Management and treatment options for patients with CT-detected lung masses are expanding as new research emerges. Radiologists with the International Early Lung Cancer Action Program, for example, recently reported that small mediastinal masses found in high-risk cancer patients during screening can be followed rather than treated.

This advice is based on a study of almost 10,000 I-ELCAP patients published in the May issue of Radiology. About 70 mediastinal masses were detected in the group at the time of screening, including 41 in the thymus and 16 in the thyroid. Repeat screening showed little change in these masses.

If lung screening is to be cost-effective, it's important to work up patients appropriately and avoid unnecessary interventions, particularly invasive procedures, said lead author Dr. Claudia Henschke, a professor of radiology at Cornell University.

"Some think if a lesion is detected, it immediately needs to be taken out. But experience shows that even in older people, if a thymic lesion is less than 3 cm, you can afford to wait and see for one year. Some grow, some decrease in size. Most stay the same," Henschke said.

The New York researchers have also found that early lung cancers detected at stage 1 are less likely to have lymph node involvement. This finding, based on close to 30,000 I-ELCAP patients, is important because these cancers are more likely to be curable, Henschke said. Results were published in February in the Archives of Internal Medicine.

Ablation may become a more widely used technique in the future for smaller cancers detected at earlier stages in high-risk screening, said Dr. Damian Dupuy, a professor of diagnostic imaging at Brown Medical School. CT-guided radiofrequency ablation is being used successfully in combination with radiation therapy for the treatment of solid lung cancers in patients who are not eligible for surgery.

Dupuy and colleagues published positive results with 24 patients in the April issue of Chest, and they have also performed combined therapy successfully in more than 60 other patients in various organ systems.

LOCAL CONTROL

Radiation therapy is the standard treatment for patients who cannot undergo surgery, but treatment fails in many cases. Sometimes failure is related to tumor hypoxia, because radiation treatment requires oxygen to damage tumor DNA and cause cell death. With ablative techniques, the dominant mass can be killed right away with heat or cold. The residual tumor at the periphery is not in a hypoxic environment and therefore is more responsive to treatment with radiation therapy.

"We get more local control and local kill by combining methods rather than using the methods alone," Dupuy said. "The results demonstrate the true clinical synergy between radiation therapy and thermal ablation. This is a significant finding that will lead to many new ways of treating solid tumors that cannot be treated surgically. I think, ultimately, combination therapies will prevail and maybe even replace surgery down the line as we discover tumors sooner and at an earlier stage."

Multislice CT makes it possible to detect smaller cancers earlier, when local therapy is much more effective.

"If we develop a good screening program and show we improve survival by catching cancers early when they are small, we might be able to use ablative techniques on these screen-detected lung cancers and avoid costly surgery," he said.