Is it possible to get six pack abs with pectus excavatum?

Yes: Pectus excavatum means the chest has a sunken appearance. If no heart or lung problems are present, the abdomen is unaffected. Six-pack abs requires eliminating fat and proper exercise program. Fat obscures the definition of the abs. To shed it requires proper nutrition and aerobic conditioning e.g. Running. Women naturally store more fat than men, so it is harder to have well defined abs. Body fat low enough to have a six-pack may stop menstrual cycles, which is unhealthy.

Yes: Excercise is excellent for patients with pectus excavatum.

Yes: Pectus excavatum is usually associated with flaring of the lower costal margins or rib cage. This could affect the appearance of six pack abs. But you can still have them and it will take the same amount of work.