What are the odds of beating stage 3a nsclc at age 55?

Good attitude. Survival for lung cancer is stage specific. Early stage has better survivalmthen late stage. However if you are being treated for lung cancer, the important thing is to stay positive and optimistic, regardless of the stage.
Nsclc. 5yr survival is about 20 percent but depends on exactly whether nodes micro or macro mets also whether surgery done or not.
Be positive. Survival rates are population based. Specific survival is individual, either 100% or 0%. Key to cancer survival is individual wellness and comprehensive multidisciplinary approach. If indicated, surgical resection should be performed by a thoracic surgeon. I hope this link assists you: http://goo.Gl/2cdq9.
Stage IIIA prognosis. Survival rates are at best rough estimates. Stage is important. Other prognostic indicators include "performance status", overall health, weight loss, lung symptoms and function, age, and how well the cancer responds to treatment. Given these variables, studies have demonstrated 25% 5 yr survival with treatment. Please discuss your individual case with your oncology team. Wishing you well.