What is breast conservation therapy?
The increase in early detection of tumors has enabled a growing number of breast cancer patients to opt for breast conservation therapy (BCT), which involves tumor excision via lumpectomy followed by radiation therapy, to reduce the likelihood of recurrence. However, more than 40% of patients with early stage breast cancer still choose to have a mastectomy, despite comparable long-term recurrence and survival rates1.
Why do so many women choose to have a mastectomy when BCT is an option?
There are many different answers to this question, and it depends on the patient and the patient's physician. Concern about the time and travel burden associated with conventional radiation therapy has been reported among women choosing mastectomy.
Additionally, physical, emotional and practical considerations, as well as a physician's clinical preference, may all influence a patient's decision.
How has conventional radiation therapy been tolerated by BCT patients?
For almost all patients, the conventional radiation therapy regimen of daily radiation treatments for six (6) consecutive weeks is an obstacle to overcome. This consuming schedule can be disruptive, if not emotionally draining, and in some instances, may not be logistically feasible due to work, parenting commitments or lack of transportation.
Close to one-fifth of early stage breast cancer patients do not receive the recommended radiation treatment after lumpectomy. In fact, the chance of a patient receiving radiation following surgery decreases 3% for every 5 mile increase in distance to a radiation treatment facility2. Omission of radiotherapy is associated with a threefold increase of breast tumor recurrence3.
What is the MammoSite® Radiation Therapy System (RTS)?
The MammoSite® Radiation Therapy System (RTS) is a tumor site-specific radiation therapy system for breast cancer. The device is comprised of a balloon catheter that allows physicians to internally administer the prescribed dose of radiation to targeted breast tissue in a five (5) day course of therapy. By internally delivering radiation directly to the tissue surrounding the original tumor, the MammoSite RTS minimizes exposure to the rest of the breast, skin, ribs, lungs and heart. The MammoSite RTS was cleared for use by the U.S. Food and Drug Administration (FDA) in May 2002.
Why was the MammoSite RTS developed?
The MammoSite RTS was developed to make it easier for more women to consider the choice of lumpectomy and to provide physicians with an important new tool for the practice of breast conservation therapy.
How is treatment with the MammoSite RTS administered?
During the lumpectomy procedure or shortly thereafter, the deflated MammoSite balloon is placed inside the tumor resection cavity.
The applicator shaft, a tube connected to the balloon, remains outside the breast. Once in place, the balloon is inflated with saline to fill the cavity. The balloon remains inflated for the entire time that the patient is receiving radiation therapy. After the balloon is inflated, the catheter exit site is dressed and the patient may go home.
The patient returns to the hospital or clinic for treatment on an outpatient basis where a radioactive "seed" is inserted within the inflated balloon, beginning a sequence of two daily 15-minute treatments over the course of five days. No source of radiation remains in the patient's body between treatments or after the final procedure. When the therapy is concluded, the balloon is deflated and the MammoSite catheter is removed.
Is the radiation exposure potentially harmful to the patient?
The MammoSite RTS is a balloon catheter that delivers radiation from within, directly to the tissue surrounding the original tumor. MammoSite RTS delivers the prescribed dose of radiation to the specific site where recurrence is most likely to occur, minimizing the potential for exposure to the rest of the breast, skin, ribs, lungs and heart. No source or radiation remains in the patient’s body between treatments or after the final procedure.
What clinical data is available on MammoSite?
MammoSite is the mostly widely-used therapy in a category called partial breast irradiation (PBI). MammoSite has been used to treat more than 16,000 breast cancer patients. The first four-year data presented at the American Society for Therapeutic Radiology and Oncology meeting in October 2005 demonstrated that no patients experienced recurrence after treatment with MammoSite. A five-year follow-up study published in the Journal of the National Cancer Institute found that PBI using a similar technique to MammoSite RTS produces comparable results to conventional whole breast radiation therapy in preventing breast cancer recurrence in appropriately selected women treated with BCT.
Can any breast cancer patient be treated with the MammoSite RTS?
The MammoSite RTS is cleared to internally administer the prescribed dose of radiation to a targeted area. Safety and performance of the device for internal delivery of radiation to targeted breast tissue were demonstrated in a multi-center study, which involved women with early-stage breast cancer. The American Society of Breast Surgeons and the American Brachytherapy Society recommend partial breast irradiation (PBI) be considered in women over the age of 45 with small total tumor size (3 cm or less), among other selection criteria.
Does treatment with MammoSite RTS cause side effects?
MammoSite RTS has been carefully tested in a clinical trial. Following the treatment, study participants experienced breast-related side effects, such as but not limited to redness, bruising and breast pain. All of these are common side effects of breast surgery and/or radiation therapy, and are usually only temporary. Four-year follow-up data on patients involved in MammoSite’s clinical trial reflect good to excellent cosmetic results in patients.
Is treatment with the MammoSite RTS covered by health insurance?
Radiation therapy with internal radiation is covered by many insurers. Specific coverage for the MammoSite RTS will depend on a patient’s individual health care plan.
1 National Cancer Institute
2 Voti L, Richard LC, Reis IM, et al Treatment of local breast carcinoma in Florida. Cancer. 2005; 106(1): 201-207
3 Vinh-Hung V, Verschraegen C. Breast-conserving surgery with or without radio therapy: Pooled-analysis for risks of ipsilateral breast tumor recurrence and mortality. J Nat Cancer Inst. 2004: 96(2): 115-121
Information courtesy of MammoSite.