Statistically, how common for a 1st time dx of breast cancer to be stage 3 or 4?

Very common. Especially if the mass has been there for a while or you haven't done monthly self-exam. I wish this weren't true. Now, please be brave and do what you know you must.

Related Questions

What is the best weight for me at age 44 being 5'5" and having had stage 3 triple + breast cancer at age 42?

Ideal weight. This link to the cdc should help; http://www.Cdc.Gov/nccdphp/dnpa/healthyweight. Read more...
Not just weight. Congrats to being a survivor! knowing your weight is important but focus on being healthy. Exercise 3-4 times per week for 30 min. Eat plenty of fruits & veggies, choose lean meats and limit sugary sweets. When exercising, incorporate weight lifting...When you have more muscle, you can burn more fat (even when not excercising). Wishing you continued good health! Read more...