Available by the National Institutes of Health in September 2016, this dateless microscope image shows a culture of human breast cancer cells. A study discussed at the 2022 meeting of the American Society of Clinical Oncology shows that some patients with malignant breast cancer may miss radiation after lumpectomy. (Ewa Krawczyk, National Cancer Institute through AP)
Estimated study time: 3-4 minutes
WASHINGTON – After surgery, some cancer patients can safely skip radiation or chemotherapy, according to two studies that have found shorter, softer care for cancer.
Researchers are looking for ways to accurately predict cancer patients to avoid unnecessary treatment in order to reduce side effects and unnecessary costs.
A new study used blood tests to determine if patients with colon cancer could skip chemotherapy after surgery. Another danger suggests that some breast cancer patients may miss radiation after lumpectomy.
The study was discussed at the annual meeting of the American Society of Clinical Oncology, which ended Tuesday in Chicago. A study on colon cancer, funded by the Australian and U.S. governments and nonprofits, was published Saturday in the New England Journal of Medicine.
The research will allow doctors to “focus on patients who we think will really benefit from chemotherapy and avoid side effects for patients who don’t need it,” the doctor said. Stacey Cohen of the Fred Hutchinson Cancer Center in Seattle reviewed the results of colon cancer and did not participate in the study.
Although many patients with colon cancer recover, chemotherapy is given after surgery. Medications can come with side effects such as dizziness, anemia and memory problems.
However, it was difficult to determine which patients might not require further treatment. Researchers have found that blood tests can be used to call doctors.
The study involved 455 patients who underwent surgery for cancer that had spread to the colon wall. After the operation, many received a blood test adapted to the genetic profile of the tumor to identify the remaining bits of cancer DNA.
Their care was guided by a blood test: if it showed no other signs of cancer, patients did not receive chemotherapy. At the same time, doctors made chemical decisions for the remaining patients in the usual way, guided by the analysis of tumors and nearby tissues.
Fewer patients in the blood test group received chemotherapy – against 15%. 28%. However, approximately 93% of the two groups recovered from cancer two years later. In other words, the blood test group was equally good with less chemotherapy.
“Patients whose cancer DNA has not been detected after surgery have a very low chance of recurrence, indicating that chemotherapy has very little benefit for these patients,” he said. The study was led by Jeanne Tie of the Peter McCallum Cancer Center in Melbourne, Australia.
The omission of chemotherapy “makes a big difference in a person’s quality of life if the risk of recurrence can be eliminated,” said ASCO President Dr. Everett Vokes specializes in head, neck and lung cancer at the Medical University of Chicago.
Another study followed 500 older women who had low levels of a protein called Ki67, a common type of early-stage breast cancer and a sign of fast-growing cancer.
After the operation, the women took hormone-blocking pills, the standard treatment for this type of cancer, but they did not receive radiation treatment.
Five years later, 10 women were diagnosed with recurrence of breast cancer, and one died of breast cancer. There were no comparison groups, but the researchers said the results were better than historical data for patients with similar radiation exposure.
“We believe that the benefits of radiation will be very small in this population compared to the negative effects,” the doctor said. Timothy Whelan of McMaster University in Hamilton, Ontario, led the study, which was supported by the Canadian Breast Cancer Foundation and the Canadian Cancer Society.
Radiation can cause skin problems, fatigue and often long-term heart problems and secondary cancer.
The study is a “good feeling” statement for patients with low-risk tumors and will help doctors understand which of their patients can “reliably” transfer radiation, the doctor said. Deborah Axelrod did not participate in the NYU Langone Health study.
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