Advances in breast cancer diagnosis and treatment are saving lives

Aside from skin cancers, breast cancer is the number one cancer that occurs in women. The good news is that more women than ever are surviving the disease. The American Cancer Society reports that deaths from breast cancer dropped 40 percent from 1989 to 2017.

The average current five-year survival rate for women in the United States with non-metastatic invasive breast cancer is 90 percent. The average 10-year survival rate is 84 percent.

Those statistics reflect the advances researchers have made in recent years. There have been some really exciting developments, according to Cape Cod Hospital Breast Surgeon Jill Oxley, MD, FACS, who is medical director of Breast Care Services for Cape Cod Healthcare.

Lymph Node Surgery

One of the significant advances in breast cancer treatment is in lymph node surgery. Lymph nodes in the underarm, or axilla, are removed to assess for spread of cancer outside of the breast. In the past, women with breast cancer typically had an axillary lymph node dissection performed as part of their surgery, meaning several lymph nodes were removed for analysis, whether or not there was spread of cancer.

About 20 years ago, sentinel lymph node biopsy became the new standard of care for women going into surgery without any evidence of cancer having spread to these lymph nodes, Dr. Oxley said. Sentinel lymph node biopsy involves mapping the lymphatic drainage of the breast and removing only the first nodes in the underarm to see if they contain cancer cells.

The biggest reason not to remove more lymph nodes than necessary is because of the risk of lymphedema, or arm swelling, resulting from lymph node surgery.

“When we are able to do a sentinel lymph node biopsy, the risk of lymphedema is about 5 percent, but it can be 20 percent or higher when we do the more extensive axillary lymph node dissection, especially if there are other treatments on top of that. Radiation, but also chemotherapy, can increase that risk,” Dr. Oxley said.

For several years, if any cancer had spread to sentinel lymph nodes, more would then be removed. Then, in 2011, a ground-breaking study called Z0011 showed that for women with less than three cancerous sentinel lymph nodes, there is no difference in outcomes if surgeons remove more lymph nodes or not. That’s only applicable to women who are having breast conservation surgery, or lumpectomies, Dr. Oxley said, but that has also decreased the number of axillary dissections.

More recent studies have led surgeons to perform sentinel lymph node biopsies in women who were having chemotherapy before surgery. A study called Z1071 showed that even if a woman had cancer in her lymph nodes before chemotherapy, if they became normal-looking afterwards, surgeons could safely do a sentinel lymph node biopsy.

Other surgical techniques such as axillary reverse mapping and lymphovenous anastomosis also allow doctors to limit the risk of lymphedema.

“We are able to decrease the number of women who need a full axillary lymph node dissection and that’s huge in reducing the chances of lymphedema, because lymphedema is not curable,” Dr. Oxley said. “It’s highly treatable, especially if caught early, which is why we have our Lymphedema Prevention Program and other surgical techniques, but it’s better, of course, to avoid it if we can.”

Early detection of lymphedema helps identify which patients can benefit from treatments for the condition. At Cape Cod Healthcare Breast Surgery - Hyannis, they use a device called SOZO, which uses bioimpedance to monitor for the development of lymphedema. That means they can get patients referred to lymphedema therapists much sooner, which improves outcomes, she said.

“We are able to decrease the number of women who need a full axillary lymph node dissection and that’s huge in reducing the chances of lymphedema, because lymphedema is not curable,” Dr. Oxley said. “It’s highly treatable, especially if caught early, which is why we have our Lymphedema Prevention Program and other surgical techniques, but it’s better, of course, to avoid it if we can.”

Therapeutic Improvements

From a non-surgical aspect, genomic testing has been a big advancement in breast cancer care in recent years. Instead of automatically doing chemotherapy based on a patient’s age or lymph node status, women who have hormone-positive, HER2 receptor negative breast cancer, which is the most common type, can now have their tumors tested to see whether they would benefit from chemotherapy or not.

For example, the Oncotype DX test looks at 21 different genes in the primary tumor. When the data first came out, results were divided into three categories: low risk, intermediate risk and high risk, Dr. Oxley said.

In 2018 the TAILORx study randomized women in the intermediate group to have chemotherapy or not. That study showed that the majority of women in that group would not benefit from chemotherapy. That eliminated the intermediate group and now there is just a high-risk group and a low-risk group, but the definition changes whether or not you are over the age of 50. For someone who has a low recurrence score, there is no benefit to adding chemotherapy to endocrine therapy.

According to the National Cancer Institute, the study indicated that chemotherapy could be avoided in about 70 percent of women in the study with HR positive, HER2 negative, node-negative breast cancer with the following guidelines:

• A recurrence score of 11 – 25 in women over 50 (45 percent of the women)
• A recurrence score of 1 – 10 at any age (16 percent of the women)
• A recurrence score of 11 – 15 in women 50 years and younger (8 percent of the women)

Meanwhile, chemotherapy should be considered for the remaining 30 percent of women with:

• A recurrence score of 26 – 100 at any age (17 percent of the women)
• A recurrence of 16 – 25 in women under 50 (14 percent of women)

The exception is premenopausal women under the age of 50 who were at the higher end of the intermediate risk range. The study showed there may be a small benefit from chemotherapy for those women.

The TAILORx study was for cancer that had not spread to the lymph nodes. The subsequent RxPONDER study included women who had between one and three lymph nodes involved in the spread of cancer. That study found that postmenopausal women with scores up to 25 would not benefit from chemotherapy, Dr. Oxley said.

“A lot of this is about what we call de-escalation – not giving patients more treatment than we have to,” she said. “From the lymph node surgery standpoint, from the chemotherapy standpoint, really trying to target therapies and not overtreat.” 

Screening Improvements

Another medical advancement that has led to improved care is the screening guidelines changes. The National Comprehensive Cancer Network (NCCN) just updated its guidelines last month to recommend that every woman have a risk assessment at age 25, Dr. Oxley said. For women who are at average risk of breast cancer, they recommend starting annual mammogram screening at age 40.

Those guidelines are in line with what the American Society of Breast Surgeons and the American College of Radiology also recommend.

“Starting mammograms at age 40 is associated with the greatest reduction in deaths from breast cancer,” Dr. Oxley said, but she pointed out that age is just for women of average risk. “For women who are at increased risk, screening with MRI can start as young as age 25, potentially with mammograms as young as age 30. So, screening is really individualized as well. We definitely want to get the word out for everyone to have a formal risk assessment at age 25 or certainly by age 30, especially for women who are black or of Ashkenazi Jewish ancestry.”

Other advances in screening include expanded genetic testing. Doctors can now test for more than two dozen mutations associated with the risks of various cancers, not just breast and ovarian cancer. All of the Cape Cod Healthcare breast imaging centers have 3D mammography. There is also more MRI availability, including a Fast MRI to screen women with dense breasts more accurately.

“The way we are able to individualize both screening and treatment has really let us tailor therapies to an individual cancer,” Dr. Oxley said. “We don’t have a one-size-fits-all approach. We have a very individualized approach to both screening and treatment.”