Will Rogers phenomenon revisited: Stage migration as detected by PET/CT and improved survival of patients with non-small cell lung cancer.

Objectives The Will Rogers phenomenon occurs when newer technology allows for more sensitive detection of tumor spread, resulting in stage migration and an apparent improvement in patient survival. Similarily, reference centers for pathology and radiology improve the quality of treatment. To quantify this effect a re-analysis of a phase III clinical trial was performed.

Methods 1. 210 eligible pts with NSCLC stage III were randomized within a phase III clinical trial after conventional staging (CT, MRT, bone scan, ultrasound). In a second step, a PET/CT was performed prior to therapy followed by calculation of the corresponding Kaplan-Meier estimates (conventional staging vs. PET/CT staging). 2. Retrospective analyses of the PET/CT data by a reference center (radiology and nuclear medicine).

Results 1. Upstaging by PET/CT in 27/210 pts (13%) downstaging in 6/210 pts (3%). Detektion of a 2nd carcinoma in 3/210 pts (1.5%). Stage-Migration 16%. Tumor specific survival (Intent to Treat Analyse) of all pts after 24, 36, 48, 60 months, only of the pts staged by PET/CT as stage III. 2. Re-analysis of the CT/MRT data: Stage migration IIIA to IIIB (13%), IIIB to IIIA (2%), IIIB to IV (2%), resulting in a statistically not significant shift of all factors in the treatment arms.

Conclusions Results of clinical trials are influenced not only by the used staging methods but also by established reference centers in pathology and radiology.