TY - JOUR
T1 - Combined Radiation Therapy and Immune Checkpoint Blockade Therapy for Breast Cancer
AU - Hu, Zishuo I.
AU - Ho, Alice Y.
AU - McArthur, Heather L.
N1 - Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Purpose Treatment with checkpoint inhibitors has shown durable responses in a number of solid tumors, including melanoma, lung, and renal cell carcinoma. However, most breast cancers are resistant to monotherapy with checkpoint inhibitors. Radiation therapy (RT) has been shown to have a number of immunostimulatory effects, including priming the immune system, recruiting immune cells to the tumor environment, and altering the immunosuppressive effects of the tumor microenvironment. RT therefore represents a promising adjuvant therapy to checkpoint blockade in breast cancer. Methods and Materials We review the data from the checkpoint blockade studies on breast cancer reported to date, the mechanisms by which RT potentiates immune responses, the preclinical and clinical data of checkpoint blockade and RT combinations, and the landscape of current clinical trials of RT and immune checkpoint inhibitor combinations in breast cancer. Results Clinical trials with checkpoint blockade therapy have demonstrated response rates of up to 19% in breast cancer, and many of the responses are durable. Preclinical data indicate that RT combined with checkpoint inhibition synergizes not only to enhance antitumor efficacy but also to induce responses outside of the radiation field. Thus multiple clinical trials are currently investigating the combination of checkpoint inhibition with RT. Conclusions The use of combination strategies that incorporate chemotherapy and/or local strategies such as RT may be needed to augment responses to immune therapy in breast cancer. Preclinical and clinical results show that RT in combination with checkpoint blockade may be a promising therapeutic option in breast cancer.
AB - Purpose Treatment with checkpoint inhibitors has shown durable responses in a number of solid tumors, including melanoma, lung, and renal cell carcinoma. However, most breast cancers are resistant to monotherapy with checkpoint inhibitors. Radiation therapy (RT) has been shown to have a number of immunostimulatory effects, including priming the immune system, recruiting immune cells to the tumor environment, and altering the immunosuppressive effects of the tumor microenvironment. RT therefore represents a promising adjuvant therapy to checkpoint blockade in breast cancer. Methods and Materials We review the data from the checkpoint blockade studies on breast cancer reported to date, the mechanisms by which RT potentiates immune responses, the preclinical and clinical data of checkpoint blockade and RT combinations, and the landscape of current clinical trials of RT and immune checkpoint inhibitor combinations in breast cancer. Results Clinical trials with checkpoint blockade therapy have demonstrated response rates of up to 19% in breast cancer, and many of the responses are durable. Preclinical data indicate that RT combined with checkpoint inhibition synergizes not only to enhance antitumor efficacy but also to induce responses outside of the radiation field. Thus multiple clinical trials are currently investigating the combination of checkpoint inhibition with RT. Conclusions The use of combination strategies that incorporate chemotherapy and/or local strategies such as RT may be needed to augment responses to immune therapy in breast cancer. Preclinical and clinical results show that RT in combination with checkpoint blockade may be a promising therapeutic option in breast cancer.
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U2 - 10.1016/j.ijrobp.2017.05.029
DO - 10.1016/j.ijrobp.2017.05.029
M3 - Review article
C2 - 28816141
AN - SCOPUS:85027696507
SN - 0360-3016
VL - 99
SP - 153
EP - 164
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 1
ER -