Almost all women get radiation therapy after lumpectomy to reduce the risk of the cancer coming back (recurrence).
Lumpectomy plus radiation has been shown to be as effective as mastectomy without radiation for most women diagnosed with early-stage breast cancer.
Radiation isn’t given routinely after mastectomy, but it is recommended when the cancer:
- is larger than 5 cm (about 2 inches)
- has spread to four or more lymph nodes (called positive or involved nodes)
- has positive margins (cancer is found in the rim of tissue around the cancer that is also removed)
- has spread to the skin
A study found that many women diagnosed with breast cancer that has spread to four or more lymph nodes don’t get radiation therapy after mastectomy, even though oncology guidelines recommend it.
The study was published online on Jan. 14, 2015 by the Journal of the American College of Surgeons. Read the abstract of “Postmastectomy Radiation for N2/N3 Breast Cancer: Factors Associated with Low Compliance Rate.”
While the stage of a cancer is usually expressed as a number on a scale of 0 through IV, there is another staging system created by the American Joint Committee on Cancer. This system, also called TNM, is based on the size of the tumor (T), lymph node involvement (N), and whether the cancer has spread to other parts of the body (M). N2 cancer has spread to between four and nine underarm lymph nodes but no other places in the body away from the breast. N3 cancer involves 10 or more underarm lymph nodes.
Since 2000, the National Cancer Institute (NCI) and the American Society of Clinical Oncology (ASCO) have recommended radiation therapy after mastectomy, as well as chemotherapy, for breast cancer that has spread to four or more lymph nodes.
The NCI, part of the National Institutes of Health, is the federal government's principal agency for cancer research. The NCI conducts, coordinates, and funds cancer research, training, health information distribution, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. ASCO is a national organization of oncologists and other cancer care providers. ASCO guidelines give doctors recommendations for treatments that are supported by much credible research and experience.
In this study, the researchers looked at a national database of cancer case information maintained by the American College of Surgeons Commission on Cancer and the American Cancer Society. The database includes about 70% of newly diagnosed cancer cases in the United States.
The researchers looked at the records of 56,990 women diagnosed with N2 or N3 breast cancer between 1998 and 2011 to see how many received radiation therapy after mastectomy.
The records showed that only 65% of the women were getting the recommended radiation therapy after mastectomy.
The researchers also looked to see if certain factors affected whether the women got radiation therapy after mastectomy to remove N2 or N3 breast cancer.
They found that socioeconomic factors such as race/ethnicity, income levels, education levels, health insurance status, and other illnesses had no effect on whether the women received radiation therapy.
Only three factors were linked to a woman being more likely to receive radiation therapy after mastectomy. They were:
- being treated with chemotherapy
- being readmitted to the hospital within the first month after mastectomy
- being alive 30 days after mastectomy
The women in the study were 5.4 times more likely to get radiation if they also received chemotherapy. Overall, 82.1% of the women in the study were treated with chemotherapy. The researchers think that women who didn’t want to be treated with chemotherapy also might not want to be treated with radiation.
The women in the study were 1.14 times more likely to get radiation if they were readmitted to the hospital within 30 days after mastectomy because of complications from surgery or for other reasons. The researchers suggested that when a woman was back in the hospital, healthcare providers may have realized that she wasn’t referred for radiation therapy and then recommended it for her.
The researchers said they couldn’t tease out why nearly a third of the women weren’t receiving radiation therapy after mastectomy to remove N2 or N3 breast cancer. It could be that women were refusing the treatment, or it could be that there is a lack of awareness among women and their doctors about the need for radiation therapy after mastectomy for breast cancer with certain characteristics.
"If women with N2/N3 breast cancer who plan a mastectomy are not offered [radiation after mastectomy], they should ask their physician why,” said Dr. Quyen Chu, M.D., professor of surgery at Louisiana State University and lead author of the study.
If you’ve been diagnosed with breast cancer that has spread to four or more lymph nodes, you and your doctor will consider the specifics of the cancer, your unique situation, and your treatment options after surgery when creating your treatment plan. If you’ll be having mastectomy and radiation after surgery isn’t recommended for you, you might want to ask your doctor why and talk about this study.
You can learn more about radiation after breast cancer surgery in the Breastcancer.org Radiation Therapy section.