Ask the Doctor: Understanding the Role of Radiation in Early Stage Breast Cancer

By Manjeet Chadha, MD, Associate Chair of the Department of Radiation Oncology at Beth Israel Medical Center in Manhattan and Associate Professor of Radiation Oncology at Albert Einstein College of Medicine

Introduction

In 2008 approximately 240,000 women will be diagnosed with breast cancer. As a result of routine mammographic screening, a high proportion of these patients will have early-stage disease. Radiation therapy is an important component of the multidisciplinary care of early stage breast cancer. Recent technological advances and an improved understanding of the biology of breast cancer have identified new and effective radiation treatment alternatives in the management of the disease. To receive individualized care, women need to understand their treatment options, and in consultation with their doctors participate in the process of making shared medical decisions.

Q. Why would I need radiation therapy?
A. Radiation therapy is the recommended local treatment for breast cancer after limited breast surgery that only removes the tumor (lumpectomy) with sampling of the axillary lymph nodes. Radiation therapy prevents local recurrence and contributes to improved long-term overall survival. In addition, the significant benefit of the combination of lumpectomy and radiation therapy is that women are given the option of keeping their breasts, while realizing the same survival outcomes as a mastectomy would provide.

Patients undergoing a mastectomy do not routinely require radiation therapy. However, in select circumstances (large tumors, many involved lymph nodes, or cancer noted at the edges of the mastectomy specimen) additional treatment with radiation following mastectomy can improve the outcome. Women should discuss their individual circumstances with their physician to determine whether radiation therapy after a mastectomy is indicated.

Q. What is a radiation oncologist?
A. Radiation oncologists are highly trained cancer physicians who directly oversee the care of patients undergoing radiation therapy. Radiation oncologists consult with patients and are responsible for making appropriate medical recommendations, and prescribing personalized radiation therapy plans for treatment. Radiation oncologists work alongside the medical and surgical oncologists as part of the multidisciplinary team.

Q. How is radiation therapy delivered?
A. Radiation therapy uses high-energy radiation waves or particles to kill cancer cells by blocking their ability to divide and increase in number. There are three different ways in which radiation therapy can be delivered:

  • External beam therapy is the most common technique. It is delivered with a highly sophisticated machine called a linear accelerator, often referred to as a “linac.”
  • Brachytherapy, also known as internal radiation therapy, is delivered via radioactive seeds or pellets that are temporarily placed in proximity to the original cancer inside the breast at the time of surgery.
  • Intraoperative radiation therapy (IORT) is the delivery of radiation therapy in the operating room at the time of surgery. Radiation oncologists can use external beam therapy or brachytherapy for this treatment. There are only a few select centers in the US that have the expertise to deliver IORT.

Q. Is radiation therapy safe?
A. Radiation therapy is carefully planned to ensure that accurate dose is delivered to the tumor site while sparing or minimizing radiation exposure of surrounding normal tissues.  The medical application of radiation has made significant advances, ensuring quality, accuracy, and safety for use as a cancer treatment.

Q. What are the recent improvements in delivering breast radiation therapy?
A. Key advances in the past several years—including biological advances identifying the genetic make up of cancers and other important prognostic factors, improved understanding of how cancers grow, and where there is the highest risk of the disease coming back—have provided us with improved understanding of breast cancer. Clinical trials have shown that a shorter course of radiation therapy, completed in three weeks, may be just as effective as the standard, six- to seven-week schedule. As a result, we now have an opportunity to select patients for shorter schedules of radiation therapy.

Another ongoing clinical trial is comparing whole-breast radiation therapy to treating only the area of the breast from where the tumor was removed. This is referred to as partial-breast irradiation (PBI) and is delivered over one week duration. The efficacy of PBI is under study, and should be considered investigational requiring special treatment consent. Patients should discuss with their physician the treatment course that best suits their individual case and confers the best outcome.

Technological advances such as three-dimensional conformal radiation therapy and intensity-modulated radiation therapy—external beam techniques using computerized axial tomography (CAT) imaging and highly sophisticated computerized treatment planning programs has enhanced the safety and accuracy of radiation dose delivered. These techniques give a precise map of the tumor area and the surrounding normal structures and allow radiation oncologists to customize the radiation dose to targeted regions while sparing nearby normal tissues.

Q. What are the side effects of radiation therapy?
A. Radiation therapy is usually well tolerated, and patients are encouraged to continue their regular day-to-day activities. Most side effects reported are temporary in nature and individual variation in the intensity of the side effects is observed. The most common side effects are noted in the treated area. Some patients report mild to moderate fatigue.

The radiation oncologist and the radiation oncology nurse are the best professionals to consult for advice on how to cope with the side effects of radiation therapy.

Q. What key things can women do to help get through radiation therapy?
A. It is important that a woman understand her individual risks and have a direct dialogue with her physician so that ongoing symptoms are addressed responsibly. Managing expectations is also an important aspect of overall care. Maintaining nutrition and getting plenty of rest are advised to cope with the associated fatigue. Even though most patients generally feel well during radiation therapy, dealing with the diagnosis and the treatment can cause emotional and physical strain. It is helpful to seek support from family, close friends, a social worker, or a group of other breast cancer patients.