Radiosensitivity Differences Between Liver Metastases Based on Primary Histology Suggest Implications for Clinical Outcomes After Stereotactic Body Radiation Therapy.
Evidence from the management of oligometastases with stereotactic body radiation therapy (SBRT) reveals differences in outcomes based on primary histology. We have previously identified a multigene expression index for tumor radiosensitivity (RSI) with validation in multiple independent cohorts. In this study, we assessed RSI in liver metastases and assessed our clinical outcomes after SBRT based on primary histology.



Patients were identified from our prospective, observational protocol. The previously tested RSI 10 gene assay was run on samples and calculated using the published algorithm. An independent cohort of 33 patients with 38 liver metastases treated with SBRT was used for clinical correlation.



A total of 372 unique metastatic liver lesions were identified for inclusion from our prospective, institutional metadata pool. The most common primary histologies for liver metastases were colorectal adenocarcinoma (n=314, 84.4%), breast adenocarcinoma (n=12, 3.2%), and pancreas neuroendocrine (n=11, 3%). There were significant differences in RSI of liver metastases based on histology. The median RSIs for liver metastases in descending order of radioresistance were gastrointestinal stromal tumor (0.57), melanoma (0.53), colorectal neuroendocrine (0.46), pancreas neuroendocrine (0.44), colorectal adenocarcinoma (0.43), breast adenocarcinoma (0.35), lung adenocarcinoma (0.31), pancreas adenocarcinoma (0.27), anal squamous cell cancer (0.22), and small intestine neuroendocrine (0.21) (P<.0001). The 12-month and 24-month Kaplan-Meier rates of local control (LC) for colorectal lesions from the independent clinical cohort were 79% and 59%, compared with 100% for noncolorectal lesions (P=.019), respectively.



In this analysis, we found significant differences based on primary histology. This study suggests that primary histology may be an important factor to consider in SBRT radiation dose selection.
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Kamran A
KA
Ahmed
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Jimmy J
JJ
Caudell
Department of Interventional Radiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Ghassan
G
El-Haddad
Department of Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Anders E
AE
Berglund
Department of Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Eric A
EA
Welsh
Department of Biostastistics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Binglin
B
Yue
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Sarah E
SE
Hoffe
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Arash O
AO
Naghavi
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Yazan A
YA
Abuodeh
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Jessica M
JM
Frakes
Department of Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida.
Steven A
SA
Eschrich
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. Electronic address: Javier.torresroca@moffitt.org.
Javier F
JF
Torres-Roca
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology* / Q000528:radiation effects*; D008113:Liver Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011836:Radiation Tolerance; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome