How Can Postoperative Radiotherapy for Breast Cancer Be Shortened? From 5+1 to 3+1

Breast cancer is often referred to as the “pink killer” and ranks first among all malignant tumors in women. According to the latest data from the International Agency for Research on Cancer (IARC, 2018), the incidence of breast cancer among women worldwide is 24.2%, making it the most common female cancer. In China, the incidence of breast cancer has been steadily increasing year by year, with recent data showing that over 300,000 women are diagnosed with breast cancer annually.

With the combined application of surgery, radiotherapy, chemotherapy, targeted therapy, and endocrine therapy, the prognosis for breast cancer patients has improved significantly—the 10-year survival rate can reach 80%. As a result, doctors have begun to explore ways to reduce treatment-related harm while maintaining effective tumor control.

Today, we will share with you the progress in adjuvant postoperative radiotherapy for breast cancer patients and introduce a new treatment philosophy: “Less is More.”

To reduce the risk of recurrence and improve survival rates, early-stage breast cancer patients who undergo breast-conserving surgery usually receive postoperative radiotherapy. The traditional radiotherapy schedule lasts about six weeks (five weeks of whole-breast irradiation plus one week of tumor-bed boost. Specifically: Whole-breast irradiation: 50 Gy delivered in 25 fractions 2.0 Gy per session, once daily, five days per week for five weeks, Tumor-bed boost: an additional 10 Gy in 5 fractions (2.0 Gy per session for one week). This conventional regimen takes approximately one and a half months to complete.

To reduce the time patients spend traveling to and from the hospital and to help them return to normal life sooner, clinical radiation oncologists began exploring whether increasing the dose per session while reducing the total number of sessions could shorten the overall radiotherapy duration without compromising tumor control.

At first, radiation oncologists used complex computer-based formulas to calculate biologically equivalent shorter treatment regimens compared with the standard 6-week plan. However, theoretical calculations alone were insufficient. Thus, radiation oncologists in the United Kingdom initiated a large-scale, phase III multicenter randomized controlled clinical trial known as the START-B study.

A total of 2,215 early-stage invasive breast cancer patients (pT1–3a, pN0–1, M0), all of whom had undergone complete surgical resection, were enrolled. According to the advice of medical oncologists, these patients also received chemotherapy and endocrine therapy as appropriate. Participants were then randomly divided (1:1) into two groups: Control group: standard radiotherapy regimen of 50 Gy in 25 fractions over 5 weeks (plus 1 week of tumor-bed boost); Experimental group: hypofractionated regimen of 40 Gy in 15 fractions over 3 weeks (plus 1 week of tumor-bed boost), derived from the calculated formula. The goal was to determine whether the shorter radiotherapy course could achieve outcomes comparable to the standard protocol.

In September 2013, the world-renowned medical journal The Lancet Oncology published the 10-year follow-up results of the START-B trial. After a median follow-up of 9.9 years, there was no statistically significant difference in the 10-year cumulative local recurrence rate between the two groups: 40 Gy / 3-week group: 4.3%; 50 Gy / 5-week group: 5.5%; P = 0.21. Moreover, patients in the 40 Gy / 3-week group experienced lower risks of breast deformation, telangiectasia (capillary dilation), and breast edema compared with those in the 50 Gy / 5-week group.

In other words, the 40 Gy / 3-week radiotherapy regimen achieved the same level of tumor control as the conventional 50 Gy / 5-week regimen, while reducing certain side effects and improving quality of life—allowing patients to return to normal life sooner. Following the publication of these results, major international cancer radiotherapy guidelines around the world began to recommend this hypofractionated regimen as a standard treatment option.

At present, under the leadership of Professor Volker RUDAT, the radiotherapy team at Jiahui International Cancer Center has adopted a hypofractionated breast cancer radiotherapy approach in line with international guidelines. By increasing the dose per session and reducing the total number of sessions, the treatment duration is shortened to four weeks: 40 Gy in 15 fractions over 3 weeks, plus 1 week of tumor-bed boost, without affecting tumor control efficacy. This regimen means fewer hospital visits, shorter treatment cycles, and reduced radiation-related skin toxicity, helping patients complete treatment more comfortably and efficiently.

In 2018, the Jiahui International Cancer Center launched its Multidisciplinary Oncology Platform, offering services for a variety of cancers, including immunotherapy, and the diagnosis and treatment of gastrointestinal tumors, lung cancer, breast cancer, multiple myeloma, and lymphoma. Thanks to the center’s collaboration with Massachusetts General Hospital (MGH) in the United States, Jiahui adheres to international standards in cancer diagnosis, treatment planning, clinical operation, and evidence-based medical practice. This partnership promotes early cancer detection and treatment in China, striving to bring cancer care outcomes to the level of global excellence.