German Screening Program Detects Early Lung Cancer

NEW YORK—Resection with intent to cure was possible for all but one of the lung cancers identified in a German screening program using low-dose spiral CT scans. Of the 13 cancers identified, eight were stage I, Stefan Diederich, MD, a staff radiologist at the University of Münster, said at the Second International Conference on Screening for Lung Cancer. The inoperable lesion was stage IIIB. However, it was resected after preoperative chemotherapy. One lesion was small-cell cancer, six were adenocarcinomas, and six were squamous cell carcinomas.

The screening program in which the cancers were identified enrolled 919 persons (647 men and 272 women) who were recruited through media publicity.

“We suggested a minimum tobacco consumption of 20 years and a minimum age of 40 years,” Dr. Diederich said. As a result, only 24% of the participants were older than 60 years of age, the minimum for acceptance into such programs as the Early Lung Cancer Action Project (ELCAP).

The mean tobacco consumption for the group was 46 pack-years. Since pack-years are defined by the number of packs of cigarettes smoked daily, this would include a person who smoked one pack a day for 40 years, one who smoked two packs daily for 20 years, and one who smoked four packs daily for 10 years.

Under the study’s diagnostic algorithm, scans not showing any soft tissue densities are considered normal. Persons with such scans are invited to return for a repeat scan in 12 months. “If there is a soft tissue density nodule,” Dr. Diederich said, “we invite the patients for follow-up thin section scan.” Repeat scans of the whole lung are advised at 12 and 24 months.

Biopsies are recommended for any soft density lesion larger than 10 mm “unless the CT morphology strongly suggests a benign lesion,” he said. Such lesions are followed, and biopsies recommended for any that show growth. In all, 16 lesions were biopsied in the study. “We performed biopsies on only three benign lesions,” Dr. Diederich reported.

The prevalence of lung cancer in the study population was 1.2%, considerably lower than the 2.7% in the ELCAP study. However, among participants over 60 years of age, a subset comparable to the ELCAP population, the prevalence in the German study was 3.6%.

Patients in the German study will be followed for another 2 years. “We intend to collect more information on the nodules smaller than 10 mm,” Dr. Diederich said. Also to be studied are optimal inclusion criteria for tobacco consumption and patient age, and more information on appropriate screening intervals.