Hi Doctor, Recently I've Been Diagnose With Breast Cancer Called

Hi Doctor, Recently I've been diagnose with breast cancer called Invasive Ductile Carcinoma Stage IA, phase 3. My oncologist explained that I have to do surgery either lumpectomy or masectomy, then I have to do chemoterapy and the last treatment would be radiation. I am trying to go for second opinion. Based on diagnosis, is it necessary that I have to do all those steps?