Women diagnosed with early-stage breast cancer will have lumpectomy or mastectomy to remove the cancer. Almost all women who have lumpectomy will get radiation therapy after surgery. Lumpectomy plus radiation has been shown to be as effective as mastectomy without radiation for many women.
Radiation isn't routinely given after mastectomy, but some women do benefit from it. Radiation given after mastectomy is called post-mastectomy radiation therapy (PMRT).
A study has found that nearly half of older women with a higher-than-average risk of breast cancer coming back in the breast area (locoregional recurrence) aren't getting radiation after mastectomy. The study was published in the journal Cancer.
The risk of the breast cancer coming back in the breast area is linked to a number of factors, including the size of the cancer and whether it has spread to nearby lymph nodes. Doctors sometimes use the TNM system to describe the cancer. T refers to the size of the cancer: T1 and T2 breast cancers are smaller than T3 and T4 cancers. N refers to the number of lymph nodes that have cancer in them and how much cancer is in them. The higher the N number, the more the lymph nodes are involved. N numbers go from N0 to N3. M means the cancer has spread to parts of the body away from the breast (metastasized).
Experts have developed guidelines to help doctors identify high-risk women who would benefit from radiation therapy after mastectomy. The guidelines say that women with cancers sized T3 or T4 and lymph node involvement of N2 or N3 are high risk (more likely to have the cancer come back in the same breast) and would benefit from radiation therapy after mastectomy.
The researchers looked at information on breast cancer cases in a large U.S. National Institutes of Health database called SEER. They found the records of 38,000 older women diagnosed with early-stage breast cancer and treated with mastectomy. The women were diagnosed between 1992 and 2005. All the women were 66 years old or older.
The breakdown of the women's risk of the cancer coming back was:
- 60% had low risk
- 19% had intermediate risk
- 21% had high risk
Although expert guidelines recommend that all women at high risk of the cancer coming back have radiation therapy after mastectomy, only 54% did. The number of women at high risk of the cancer coming back who got radiation therapy after mastectomy went up from 1992 until the expert guidelines were released (between 1997 and 1999), but since then has gone down.
The researchers aren't sure why so many older women at high risk of the cancer coming back (46%) didn't get radiation therapy after mastectomy. In some cases doctors may not have recommended radiation therapy after mastectomy because of a woman's age or other health problems affecting her situation. In other cases it may be that women chose not to get radiation therapy after mastectomy even though it was recommended by her doctor. In some cases women may have chosen mastectomy instead of lumpectomy followed by radiation therapy to avoid radiation therapy. They then may have refused to have radiation therapy after mastectomy even if they were considered to be at high risk for the cancer coming back.
If you've been diagnosed with breast cancer, you and your doctor will consider the specifics of the cancer, your unique situation, your surgical options, and your treatment options after surgery when creating your treatment plan. If you choose lumpectomy, it's very likely that radiation will be recommended after surgery. If you choose mastectomy, you might want to ask your doctor if radiation therapy after mastectomy would be beneficial, especially if the cancer is large or has spread to more than one lymph node.
Using the most complete and accurate information, you and your doctor can develop a treatment plan that makes the most sense for you. You can learn more about radiation therapy after breast cancer surgery in the Breastcancer.org Radiation Therapy section.