One-off radiotherapy dose for breast cancer as effective as longer course
The long-term results of a massive international trial, spanning almost two decades, has shown a single session of a novel form of radiotherapy is as effective in treating most breast cancers as a conventional radiotherapy plan lasting several weeks.
For most breast cancer patients, treatment is a two-step process. First, a patient undergoes lumpectomy surgery to remove the tumor from the breast. Then, for several weeks, they undergo daily external beam radiotherapy (EBRT), beaming precisely targeted high-energy X-rays at the tumor site from outside the body. EBRT can take up to six weeks of daily sessions to complete.
An alternative approach, Targeted Intraoperative Radiotherapy (TARGIT-IORT), was first developed by a team of scientists at University College London in the late 1990s. This technique involved exposing the primary tumor site to targeted radiation during the initial surgical procedure. Early indications suggested just 20 to 30 minutes of direct radiotherapy to a tumor bed during a lumpectomy was effective.
TARGIT-IORT has become a widely available breast cancer treatment option in recent years. However, EBRT is still the primary standard-of-care option recommended by most physicians. This long-term, randomized, controlled clinical trial was designed to establish whether the novel TARGIT-IORT method is effective over many years of follow-up, compared to standard care.
More than 2,000 women were recruited for the trial. They were all diagnosed with invasive ductal carcinoma, and randomly allocated either EBRT or TARGIT-IORT. The average follow-up period in the trial was around eight years, although some subjects were followed for nearly 20 years.
Tracking cancer recurrence rates the trial found no clinically significant difference between the two treatment methods. The single, targeted shot of radiotherapy delivered during surgery was as effective as dozens of EBRT treatment sessions.
At the longest follow-up point in the study, the research revealed there were fewer deaths from “other causes” in the TARGIT-IORT group compared to the EBRT group (14 fewer deaths, 46 vs 56). This suggests the lower dose of radiotherapy may result in less long-term side effects to the body.
“These results are the highest level of evidence proving not only the effectiveness of TARGIT-IORT but confirming that it avoids deaths from other causes,” says Michael Baum, co-author on the study. “I am pleased that it will benefit thousands of breast cancer patients around the world.”
As well as reducing the physical burden of radiotherapy on the patient, TARGIT-IORT is significantly easier to administer. Patients do not have to travel to hospital daily for weeks following surgery, plus the treatment requires less resources from the hospital.
“With TARGIT-IORT, a large proportion of patients with breast cancer will never need to make the repeated daily visits to the radiotherapy center,” says co-author, Jeffrey Tobias. “They avoid side effects of whole breast radiotherapy. Importantly, TARGIT-IORT reduces the burden on overstretched radiotherapy departments.”
Jayant Vaidya, lead author on the new study, says these findings should encourage physicians around the world to offer TARGIT-IORT as a first-line treatment in appropriate breast cancer cases. It is also suggested the NHS in the UK and Medicare or Medicaid in the US should further fund TARGIT-IORT as a way of saving scarce healthcare resources. The treatment is estimated to lower the load on radiotherapy departments by reducing breast cancer patients by around 80 percent.
“With publication of these very positive long-term results, it is now clear that this treatment should be made much more freely available. It should be accessible to healthcare providers and discussed with patients when surgery for breast cancer is being planned.”
The new study was published in the journal BMJ.
Source: University College London