Chemotherapy. Most chemo is IV however some is in pill form. You'll have to ask the medical oncologist which treatment is best for the particular type of cancer.
Not necessarily. Cancers are treated with surgery, oral or parentral medications, radiation or a combination of these. Not all patients with cancer need IV drugs.
Depends. Cancer treatments can come in different form - oral tablet, intravenous, intramuscular. Depending on the type of cancer, your preferrence, and your ability to swallow etc you and your oncologist will decide what treatment and what form is the best for you.