When Carmen Brooks was diagnosed with breast cancer late last year, the 56-year-old Bridgeport resident felt the visceral fear likely common to anyone who gets such news. But there was also an underlying calm, she said. "I was a mess, like anyone would be, but I knew I would be OK," she said. Her optimism was initially confirmed after her breast surgery in February, when she was told that the doctors were able to remove all of her cancer. Even more good news followed. Brooks met with her oncologist, Dr. Richard Zelkowitz, the regional medical director of the breast program at St. Vincent's Medical Center and Hartford HealthCare, to discuss her follow-up care. "He said 'The great thing about this is, you don't need chemotherapy,'" she said. She's not alone. In 2018, a study of more than 10,000 women, published in the New England Journal of Medicine, showed that chemotherapy can be avoided in about 70 percent of women with a type of breast cancer known as hormone receptor-positive, HER2-negative, and node-negative - which accounts for about half of all breast cancer cases in the United States. Zelkowitz said research presented at a conference late last year showed that many women with hormone receptor-positive, HER2-negative and node-positive cancer might also be able to avoid chemotherapy. Chemotherapy uses anti-cancer drugs, taken either intravenously or by mouth, to attack cancer cells. The treatment can cause a variety of side effects, including hair loss, mouth sores, nausea and vomiting. Zelkowitz said the move toward less chemo isn't necessarily about being less aggressive in treatment but "about understanding the disease better," and knowing which therapies work best for different types of cancer. Still, Zelkowitz said, people are often relieved when they're told they don't need chemo. "People are obviously happy when they don't need chemotherapy," he said. "It's the first question people always ask you." Doctors can determine whether a patient would benefit from chemotherapy using gene expression tests, which are done on breast cancer cells after a biopsy or breast surgery. According to the American Cancer Society, there are multiple types of gene expression tests, including Oncotype DX, MammaPrint, and Prosigna. The tests look at patterns of different genes to determine such information as how likely a patient's cancer is to come back after initial treatment. Zelkowitz used the Oncatype test with Brooks. Oncatype is used primarily for stage I, II or IIIa hormone receptor-positive tumors that have not spread to more than three lymph nodes and are HER2 negative. Each patient is given a score from 0 to 100, which determines the risk of cancer coming back. A score from 0 to 25 means the patient has a low risk of recurrence and isn't likely to benefit from chemotherapy, and a score of 26 to 100 means there is a high risk of recurrence and the patient will benefit from chemotherapy. Other area oncologists use Oncotype with breast cancer patients, including Dr. Jamie Stratton, a medical oncologist at Stamford Hospital's Bennett Cancer Center. She said she's used it for roughly eight years, and has found it helpful in connecting patients with the best treatment for them. "It really helps us get another data point as to whether we should use chemo," Stratton said. "We found out that there were definitely patients given chemo (10 to 20 years ago) who didn't need it and didn't benefit from it." Even if a breast cancer patient doesn't need chemotherapy, they might need other treatments, including hormone therapy and radiation. Brooks is doing both of those treatments, but said she doesn't mind. "I was overwhelmed with joy that I wouldn't have to do chemo," Brooks said. "That was my concern. I still praise God and thank God for that." October is Breast Cancer Awareness Month and Brooks said her outcome proves the importance of getting an annual mammogram - something she said she does diligently. Her original tumor was detected during her mammogram. "Don't be afraid (to get tested)," she said. "Early detection is best. If there is something there, you want to make sure you get rid of it now."