Pulmonary Micronodules Less Than 5 mm Detected At Presentation In
Patients With Osteosarcoma Do Not Effect 5 Year Overall Survival
Abstract
Within the last 25 years, high-resolution CT scans have revealed
pulmonary micronodules (nodules < 10 mm) not previously seen.
For osteosarcoma (OST), staging criteria, prognosis estimates, and
surgical recommendations have not yet changed to reflect this reality,
however, the frequent identification of micronodules on presentation
leaves clinicians in a difficult position regarding the need to biopsy,
resect, or follow the lesions and whether to consider the patient
metastatic or non-metastatic. We retrospectively collected data on all
newly diagnosed OST patients, age less than 50, treated at Rush
University Hospital over 25 years without pulmonary nodules
> 10mm to study the relationship between size and location
of micronodules discovered at the time of diagnosis and its relationship
to 5 year overall survival. Kaplan-Meier curves comparing 5 year overall
survival of patients with their largest nodules on presentation at each
size interval showed there was no difference in 5 year overall survival
in patients with any size nodule < 5 mm compared to patients
with no nodules. In addition, our study showed a survival advantage for
those who presented with 0 or 1 nodule (90%) compared to ≥ 2 nodules
(53%). Additionally, patients who develop nodules after presentation
but within a year of diagnosis with any number of new micronodules had a
lower 5 year overall survival (93% vs 63%). Our data suggest surgery
may not be necessary for singular nodules < 5 mm identified on
presentation, and that these patients behave more like “localized”
patients than metastatic patients.