Data were also collected on whether cancers progressed after initial treatment. For participants with confirmed lung cancer, medical records were retrieved periodically after diagnosis and treatment to determine whether the lung cancer had progressed. A data collection form was filled out for each follow-up period (one-half year for ACRIN, one year for LSS) after diagnosis, with each form recording instances of progression that began during that follow-up period.

Progression was defined as enlargement of the original tumor, new metastasis to lymph nodes or other organ site not included in the original tumor staging, or disease recurrence. Death was not considered disease progression.

Lung cancer progression data is included in the Participant dataset.

Summary	Available Data
Data collected annually or semi-annually after diagnosis of lung cancer ~4700 forms from ~1500 cancers ~800 forms indicated progression in ~500 participants Data were collected on the following forms: LSS CP (PDF - 129 KB) ACRIN CX (ACRIN NLST CRF Set)	Whether progression occurred after treatment Days from randomization to first documentation of progression Site(s) of progression