2. phylum - (biology) the major taxonomic group of animals and plants; contains classes. phylum Pyrrophyta, Pyrrophyta-a division of lower plants comprising unicellular and biflagellate algae that form starchy compounds.. phylum - (biology) the major taxonomic group of animals and plants; contains classes. phylum Pyrrophyta, Pyrrophyta-a division of lower plants comprising unicellular and biflagellate algae that form starchy compounds.
1 Breast cancer in premenopausal women tends to be more aggressive, so chemotherapy is often part of the treatment plan. 2  Chemotherapy may be recommended for some women diagnosed with early-stage breast cancer if the cancer is hormone-receptor-negative and HER2-positive.For more information on the specific characteristics of each cancer stage, visit the Breastcancer.org Stages of Breast Cancer page.). Chemotherapy is used after surgery to remove the breast cancer to get rid of any cancer cells that may be left behind and to reduce the risk of the cancer coming back.
Radiation therapy has an important role in treating all stages of breast cancer because it is so effective and relatively safe. It may be appropriate for people with stage 0 through stage III breast cancer after lumpectomy or mastectomy.