It depends. It depends on the type of cancer, the stage of the cancers and whether surgery can be done or not. Sometimes, chemotherapy is given upfront prior to surgery to reduce the size of the cancer so that surgery can be done. Some other time, surgery is the only thing you need to cure the disease or chemo will be given after surgery. Discuss with your medical and surgical oncologist on this matter.
Depends on cancer. This depends on the specific type of cancer and the stage. For most cancers that require surgery chemotherapy is not given prior to the surgical procedure.
Sometimes. If chemo is going to be given, there can be benefits to neoadjuvant therapy. The survival impact is the same but chemo first can take someone from non-operable to operable or mastectomy to breast conservation or improve the potential for breast conservation. Chemo first also provides prognostic info based on the response of the tumor to treatment. Its an option for any stage 2, her2+, or -/-/-.