Just had chest ct scan revealing 4 nodules in base of lll (1, 5, 5, 6 mm). the 6mm is spiculated. never smoker, longtime runner. is cancer iikely?

Pretty low: The Brock University calculator gives a 1% chance that one of these nodules will become cancer within 2 years is less than 1%. If you have emphysema and/or a family history of lung cancer your risk will be higher. The calculator is here https://www.uptodate.com/contents/calculator-solitary-pulmonary-nodule-malignancy-risk-brock-university-cancer-prediction-equation

Possibilities: Lung nodules have numerous causes, including fungal or bacterial infection, sarcoidosis, lymphoma, lung cancer and cancers metastasized from other organs. Ref: https://www.reference.com/health/causes-lung-nodules-47b370eca3a0dc7b