With an earlier diagnosis of breast cancer some patients do not need chemotherapy because of their excellent prognosis. These patients may need only local therapy, such as mastectomy or lumpectomy and radiotherapy or may need local therapy plus hormone therapy. In patients who need chemotherapy, that chemotherapy will clearly increase the time they are free from cancer and decrease their chance of recurrence.
The need for chemotherapy is based on multiple tumor and patient factors. These factors include age, menopausal status, nodal status, hormone receptors and the HER2-neu gene analysis of the tumor. Most node positive patients will benefit from the addition of chemotherapy and many higher risk node negative patients will also benefit from chemotherapy. Newer tests in node negative patients, such has the gene based Oncotype DX assay, help select which node negative patients are higher risk and may benefit from chemotherapy. After all of these factors have been considered, some patients will have a great benefit with the addition of chemotherapy and some will have only a modest benefit. At that point, discussion between the patient and the physician will help to determine what risk and toxicity the patient is willing to accept for what level of benefit.
A current concept in the chemotherapy of breast cancer at the time of diagnosis is called neoadjuvant chemotherapy. This is a treatment regimen that involves giving chemotherapy prior to surgery. There are two goals: 1) converting those patients who would initially need a mastectomy to being able to have breast conserving treatment with lumpectomy and radiation therapy, and 2) evaluating the effect of chemotherapy on reducing or eliminating the cancer. Chemotherapy may be given either before or after surgical treatment with identical cure rates.
This treatment chemotherapy is given after surgery. Most drug combinations in the adjuvant therapy of breast cancer include such drugs as Adriamycin, Cytoxan, Taxol, and Taxotere. These chemotherapy regimens in general, over the past several years, have become more aggressive and shorter in length and have less toxicity compared to older regimens. This is because better anti-nausea drugs are available and drugs such as Neulasta are given to maintain normal blood count and thus greatly decrease the chance of infectious complications, which used to be a major problem with chemotherapy. In the special circumstance of tumors that over-express the HER2-neu gene, the addition of Herceptin has greatly improved the cure rate in these more aggressive tumors. The addition of Herceptin in the adjuvant treatment of breast cancer has been one of the major advances in breast cancer therapy in the last five years.
Breast cancer is said to have metastasized if it has spread beyond the area of the breast, either to the axillary lymph nodes or into other parts of the body (liver, lung, bowel). In patients whose tumors are hormone receptor positive, multiple hormonal modalities of therapy should be exhausted before proceeding to chemotherapy. There are a multitude of drugs that are used in metastatic breast cancer with the goal to prolong life with minimal toxicity.