Early breast cancer, of hormonal origin, is less likely to re-offend when it is treated with radiation therapy

Women with early, low-risk, hormone-induced bad cancer are less likely to re-emerge if they undergo radiotherapy after surgery, as well as an anti-hormonal treatment , according to the results of a trial conducted among 869 women for ten years. years.

8 An essay from the Austrian study group on bad cancer and colorectal cancer (ABCSG), presented today (Sunday) at the ESTRO 38 conference, shows that cancer has not reappeared in the same bad in 97.5% of women who had an entire bad irradiation (WBI), and in 92.4% of women who did not have WBI. After an average median follow-up of nearly ten years, there were ten bad cancer recurrences (bad recurrences) among the 439 women with WBI and 31 among the 430 women who received only one. an anti-hormonal treatment.

When the researchers examined how long women had survived without their disease recurring, the disease-free survival rate was significantly higher, 94.5% among those who had WBI, compared to 88.4% among those who had WBI. did not have any.

The cost, logistics, and possible adverse side effects badociated with WBI have led researchers to attempt to identify a subgroup of bad cancer patients who may not need radiotherapy. However, these latest results suggest that this might not be possible.

Associate Professor Gerd Fastner, of the University Clinic of Radiotherapy and Radiation Oncology at the University Hospital of the Paracelsus Medical University in Salzburg, Austria, told the conference: "Our results show that the Radiotherapy is still very effective in significantly improving local control and disease without survival in combination with anti-hormones, compared with anti-hormones alone.This remains true after long-term follow-up of patients with Breast cancer with a good prognosis In our badysis, the omission of whole bad irradiation has proven to be the major predictor of intra-mammary recurrence.

"In addition, tumors that could not have their grade rank were almost four times more likely to recur, which could be due to the fact that some of the tumors are more aggressive."

The ABCSG 8A trial recruited 869 postmenopausal women between 1996 and 2004 and randomized them to receive either anti-WBI treatment or anti-hormonal treatment after bad conservative surgery. Patients had early, low-grade, grade 1 or 2 tumors less than 3 cm in diameter and no identified cancer cells in the lymph nodes. Tumors were driven by hormones such as estrogen or progesterone and thus responded to anti-hormonal treatments such as tamoxifen or anastrozole. The patients had not received any chemotherapy, radiotherapy or previous hormone therapy.

WBI was administered at a total average dose of 50 Gy over a period of 39 days and within six weeks of the operation; 71% of patients also received an average additional stimulation of 10 Gy in the tumor bed.

If the cancer had spread to the first lymph node (sentinel) under the arm, the sentinel node would also be removed during surgery, as well as the axillary lymph nodes. In cases where no tumor cells were found in the sentinel lymph node, the removal of additional axillary lymph nodes was omitted.

The researchers found that of the 258 women whose only sentinel lymph nodes had been removed, the risk of recurrence of the disease was 75% lower if they had WBI than if they did not. However, the same benefit in terms of disease-free survival was not observed for WBI after removal of axillary lymph nodes.

Overall survival and cancer-free survival spreading to other parts of the body (metastases) were similar in women with and without WBI. "Improving tumor control at the primary site could result in better survival in the years to come," said Dr. Fastner.

A subsequent badysis of 519 patient tissues, which examined the levels of a protein called Ki-67 (an indicator of cell proliferation) and another protein, HER2 (a growth-promoting protein found outside of bad cancer cells), found that patients with high Ki-67 (greater than 20%) or HER2 positive, or both, were not at increased risk. high to see cancer return to the same bad, although there is a clear tendency to do so.

"This discovery requires additional research in larger women's groups with longer follow-up, as this could be a chance discovery because of the small number of women for whom we have this information," said the report. Dr. Fastner.

He concluded: "We believe that the additional benefits of postoperative radiotherapy have been confirmed in hormone receptor patients, whether or not they have a high risk of bad cancer recurrence." It does not necessarily mean that nowadays they must undergo total bad irradiation because partial bad irradiation has been shown to be competitive. Partial bad irradiation can be achieved with beam radiotherapy. external hypofractionated postoperative. [EBRT], intraoperative techniques or perioperative brachytherapy. The total omission of radiotherapy should be considered only in elderly and frail patients who would not be able to tolerate such treatment. "

Professor Umberto Ricardi, President of the Department of Oncology at the University of Turin, Italy, said: "In 2006, these researchers reported the results of almost five years of follow-up for these women, who showed that radiotherapy after surgery, combined with treatment with tamoxifen or anastrazole, has significantly reduced the risk of cancer recurrence.These new findings, after ten years of follow-up, show that the beneficial effects of Irradiation persists and becomes even more obvious for these women This is important information for women and their doctors, who help them to choose the best treatment for their bad cancer.Radiotherapy treatments have progressed considerably since 2006 and there are now other ways to administer radiotherapy to the bad less and more quickly-consuming compared to the irradiation of the entire bad. This study also highlights the benefits of long-term follow-up for women and the medical community. "

More information:
Abstract No .: OC-0270, "Antihormones with or without irradiation in bad cancer: Results over 10 years of the ABCSG8A trial".