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2023年圣安东尼奥乳腺癌研讨会公布的数项研究表明部分乳腺癌患者可跳过放疗

01月08日

来源：癌症研究UPDATE

以下内容原文发布于AACR官方博客《Cancer Research Catalyst》, 中文内容仅做参考，请点击文末“阅读原文”，阅览原文内容。

2023年圣安东尼奥乳腺癌研讨会（ San Antonio Breast Cancer Symposium ，SABCS）上公布的数项研究表明，某些情况下患者可能无需接受辅助放疗。

上述研究的结果证实，部分乳腺癌患者可跳过放疗，从而避免副作用和治疗相关的后勤障碍，并让患者在选择癌症治疗方案方面拥有更多的发言权。

其中一项研究的介绍人、来自埃默里大学医学院及温什普癌症研究所（Winship Cancer Institute of Emory University）的 Reshma Jagsi 博士（MD，DPhil）表示：“尽管放疗技术已有了显著进步，如今的放疗手段比以前更有效、也更易耐受，但患者仍会希望在治疗方案上拥有选择余地。"

于2023年12月5日至12月9日举行的SABCS会议上展示的研究主要针对三个不同的患者群体：

低风险导管原位癌（ductal carcinoma in situ，DCIS）患者，
50-69岁的已绝经早期乳腺癌患者，以及
新辅助化疗后淋巴结已无癌的患者。

各项研究中，研究者均对跳过放疗患者的疾病复发率和其他乳腺癌事件发生率进行了调查。

研究者发现，各项研究中放弃放疗后相关（事件的）发生率仍处于较低水平，这表明患者可以放弃放疗，并且不会对预后产生不利影响。

Jagsi博士表示：“像这样的研究......对于寻找改善患者体验的方法非常重要。一方面，通过向患者提供多种治疗方案，可帮助患者重获因癌症确诊而丧失的控制感（sense of control）；另一方面，又可确保所有患者知情并有能力做出适合自身的决定。”

了解更多内容，请阅读以下原文。

SABCS 2023: Some Patients May Safely Skip Radiation

Studies featured at this year’s San Antonio Breast Cancer Symposium (SABCS) suggest that—in some situations—adjuvant radiotherapy may not be needed.

The results could allow some patients with breast cancer to skip radiotherapy, sparing them the side effects and logistical hurdles associated with the treatment and giving them more say in how their cancer is treated.

“Although techniques of radiation treatment have improved dramatically, and it is far more efficient and tolerable now than it used to be, patients appreciate having a choice about their treatments,” noted Reshma Jagsi, MD, DPhil , who presented one of the studies. Jagsi is affiliated with the Emory University School of Medicine and the Winship Cancer Institute of Emory University.

The research presented at SABCS, which was held December 5-9, focused on three separate patient populations:

patients with low-risk ductal carcinoma in situ (DCIS),
postmenopausal patients aged 50-69 years with early-stage breast cancer, and
patients whose lymph nodes became cancer-free after neoadjuvant chemotherapy.

In each study, researchers examined rates of disease recurrence and other breast cancer events in patients who skipped radiotherapy.

And in each study, they found that these rates remained quite low—suggesting that patients could forgo radiation without adversely impacting their prognosis.

“Studies like this … are important for identifying ways to improve the patient experience, both by identifying multiple treatment options to help patients regain a sense of control that a cancer diagnosis can seem to take away, and by ensuring that all patients are informed and empowered to make the decisions that are right for them,” said Jagsi.

THE IDEA TRIAL

In her presentation, Jagsi explained that patients who are diagnosed with stage 1 hormone receptor (HR)-positive breast cancer typically undergo breast-conserving surgery followed by adjuvant radiotherapy and endocrine therapy to reduce the risk of disease recurrence.

In recent years, it’s become evident that postmenopausal patients 65 years and older could opt out of adjuvant radiotherapy while maintaining a low risk of disease recurrence, but it remained unclear whether younger patients might be able to safely forgo adjuvant radiotherapy too.

Therefore, Jagsi and colleagues conducted the IDEA clinical trial, which enrolled patients between 50 and 69 years of age who had stage 1 HR-positive, HER2-negative breast cancer. The Oncotype DX Breast Recurrence Score, a laboratory test that measures gene expression in breast tumors, was used to determine each patient’s risk of disease recurrence. The results of the test are reported as a score between zero and 100, with higher scores associated with a greater likelihood of disease recurrence.

Patients with a low risk of recurrence (defined in this study as scores 18 or lower) were eligible to skip radiotherapy after breast-conserving surgery while still receiving standard-of-care adjuvant endocrine therapy for at least five years.

Among 186 evaluable patients who had skipped adjuvant radiotherapy, 100% were alive five years after surgery, and 99% (184 patients) were breast cancer-free at this time.

“These findings indicate that younger postmenopausal patients with stage 1 breast cancer who skip radiotherapy after breast-conserving surgery have a very low risk of disease recurrence within five years,” said Jagsi.

“However, five years is an early time point for this population, and longer-term follow-up of this study and others will be essential to determine whether this option can be safely offered to women in this age group,” she added.

THE E4112 TRIAL

In another study, Seema Khan, MD , and colleagues examined the utility of adjuvant radiotherapy for patients with DCIS (a noninvasive form of breast cancer) that has a low risk of progressing to invasive cancer.

“There is an increasing realization that DCIS carries an unnecessary treatment burden for many women,” noted Khan, who is a professor at the Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

She explained that most patients with DCIS undergo breast-conserving surgery followed by adjuvant radiotherapy, which is intended to reduce the likelihood that the disease returns as DCIS or as invasive breast cancer. But whether adjuvant radiotherapy is needed for patients whose DCIS already has a low risk of returning or progressing was previously unclear.

Khan and colleagues conducted the E4112 clinical trial to assess the potential of bilateral magnetic resonance imaging (MRI) coupled with a DCIS gene expression profile to guide treatment for patients with DCIS. Previously reported results from this trial indicated that MRI could help identify patients who could opt for the less intensive breast-conserving surgery instead of a mastectomy, Khan noted.

The latest analysis aimed to determine if some of those patients who underwent breast-conserving surgery based on MRI results could also safely forgo subsequent radiotherapy based on a DCIS gene expression profile.

The analysis included 171 patients with DCIS who underwent breast-conserving surgery and whose tumor tissue was profiled using the Oncotype DX Breast DCIS Score, which, like the Oncotype DX Breast Recurrence Score, measures gene expression to predict the risk of recurrence.

In this study, patients who received a score lower than 39 were considered to have low-risk DCIS and were eligible to skip adjuvant radiotherapy, while patients with scores 39 or higher were recommended to receive adjuvant radiotherapy.

After a median follow-up of five years after surgery, 5.5% of the 75 patients with low-risk DCIS who skipped radiotherapy experienced disease recurrence, as compared with 4.8% of the 84 patients with high-risk DCIS who received radiotherapy—a difference that was not statistically significant. The findings demonstrate that patients who skipped radiation therapy did not have a greater risk of disease recurrence within five years.

“Our results indicate that the Oncotype DX Breast DCIS Score was an effective tool to stratify patients for adjuvant radiotherapy following breast-conserving surgery.” said Khan. “These findings reveal a new approach to guide treatment decisions by determining which patients may benefit from radiotherapy and which patients may safely forgo it.”

THE NRG ONCOLOGY/NSABP B-51/RTOG 1304 TRIAL

According to results shared by Eleftherios (Terry) Mamounas, MD, MPH , neoadjuvant chemotherapy may help some patients skip adjuvant regional nodal irradiation (RNI), a form of radiotherapy directed to lymph nodes near the breast. Mamounas is the chair of the NRG Oncology Breast Committee, a professor at the University of Central Florida, and medical director of the Comprehensive Breast Program at the Orlando Health Cancer Institute.

Patients who are diagnosed with breast cancer that has already spread to regional lymph nodes may receive neoadjuvant chemotherapy; in some cases, neoadjuvant therapy completely eradicates the cancer from the lymph nodes. Currently, there is no established standard of care for how these patients should be treated after surgery, Mamounas explained.

“There is an active debate on whether these patients should be treated as patients with lymph node-positive disease (which is how they were diagnosed) or as patients with lymph-node negative disease (which is how they present at the time of surgery),” he said.

If treated as patients with lymph node-positive disease, they would be recommended to undergo chest wall irradiation plus RNI after mastectomy or whole breast irradiation plus RNI after breast-conserving surgery. Alternatively, if their disease were considered lymph node-negative, they would be eligible to omit RNI after surgery.

To evaluate the impact of RNI on patient outcomes, Mamounas and colleagues conducted the NRG Oncology/NSABP B-51/RTOG 1304 clinical trial. The study enrolled patients diagnosed with lymph node-positive, nonmetastatic breast cancer whose lymph nodes were found to be cancer free after neoadjuvant chemotherapy and who had undergone either mastectomy or breast-conserving surgery.

Evaluable patients (1,556 patients) had similar outcomes whether they received adjuvant RNI or not: 91.8% of patients who skipped RNI and 92.7% of those who received RNI were free of invasive breast cancer recurrences five years after surgery. Distant recurrence and overall survival rates were also similar between the arms.

“Our findings suggest that downstaging cancer-positive regional lymph nodes with neoadjuvant chemotherapy can allow some patients to skip adjuvant RNI without adversely affecting oncologic outcomes. Follow-up of patients for long-term outcomes continues,” Mamounas summarized.

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01月09日

陈方艳

临武县人民医院 | 肿瘤内科

低风险导管原位癌（ductal carcinoma in situ，DCIS）患者， 50-69岁的已绝经早期乳腺癌患者，以及新辅助化疗后淋巴结已无癌的患者

01月08日

欧阳波

酒钢医院 | 呼吸内科

内容很精彩，值得学习！

01月08日

李景贺

深圳市龙华区人民医院 | 肿瘤内科

低风险导管原位癌（ductal carcinoma in situ，DCIS）患者， 50-69岁的已绝经早期乳腺癌患者，以及新辅助化疗后淋巴结已无癌的患者。各项研究中，研究者均对跳过放疗患者的疾病复发率和其他乳腺癌事件发生率进行了调查。