A recent study, published in The New England Journal of Medicine on Wednesday, revealed a significant finding regarding breast cancer treatment. Apparently, gene tests in tumors could help guide treatment in breast cancer patients.
Early-stage breast cancer is preemptively treated with various therapies, including chemotherapy. However, most treatment decisions do not take into account the individual characteristics of tumors, so there is a risk of overtreating patients, including women who could potentially skip said therapies without much future risk.
Breast cancer research continues to advance in the medicine field
The study was provided funding by charitable groups, drug companies, and government grants. Genomic tests were conducted on 6,693 random women with early-stage breast cancer, whose ages ranged from 23 to 71 years old, across one hundred and twelve hospitals in nine European countries.
The researchers made use of genomic tests such as MammaPrint to obtain a woman’s genomic risk. The method works by measuring the gene activity in tumors to identify which women had a high or low risk of recurrence.
Also, a modified version of the Adjuvant Online tool was used to determine clinical risk, which is based on anatomical features such as tumor size.
The contradictions breast cancer over-treatment
The research concluded that women who had high clinical and genomic risks were to be given chemotherapy, and those who had small danger in both areas are allowed to skip it, preventing overtreatment. However, contradictions exist. For example, there are women with clinical high risk and low genomic risk, and women with high genomic risk and low clinical risk.
These seemingly contradictory results are the ones the test focuses on, in particular, those of women with clinical high risk but low genomic risk, which was about a quarter of the cases in the study. These cases were randomly assigned to chemotherapy or not, according to their risks.
Genomic risk testing results
The primary endpoint of the research was to monitor survival without cancer spreading to other organs and lymph nodes far from the initial source, which is often fatal after five years. After those five years since some of the women received chemotherapy treatment and some didn’t, and the researchers made some interesting discoveries.
About 95 percent of those patients who did get treated did not experience distant spread, and those who weren’t given chemotherapy fared only slightly worse at 94 percent.
These findings mean that about 46 of women thought to be at risk could potentially skip chemotherapy without ill effects. Of course, even if this research is one of the largest and most rigorous for genomic testing, it still needs more study to verify the results entirely, as noted by an editorial that accompanied the study in The New England Journal of Medicine.
The next step for breast cancer screening and treatment
Other concerns included that the study wasn’t large enough to see if the difference between treated and untreated women would hold statistically.
However, additional research is underway. The first author of the study, Dr. Fatima Cardoso, a breast oncologist at the Champalimaud Clinical Center in Lisbon has stated that the researchers will “have to continue to follow these patients and see what happens at ten years.”
Women with a little risk of recurrence have less to gain from chemotherapy, but would expose themselves to the various risks that come with the treatment, such as leukemia and heart failure. Because of this, the research is crucial, as it could help patients avoid the possible unpleasant side effects.
Source: NY Times