Stereotactic Ablative Radiation Therapy for Colorectal Liver Metastases

Targeting SLC7A11 with sorafenib sensitizes stereotactic body radiotherapy in colorectal cancer liver metastasis

Colorectal cancer (CRC) with hepatic metastasis is associated with poor prognosis. Stereotactic body radiotherapy (SBRT) can provide local control for unresectable hepatic metastases of patients with CRC. However, the mechanisms of responsiveness to SBRT in metastatic CRC (mCRC) remain unclear. We aimed to identify a strategy to enhance the efficacy of SBRT in patients with CRC liver metastases and its mechanisms. Transcriptomic sequencing of CRC cells exposed to SBRT revealed that SBRT inhibited SLC7A11 expression. Downregulation of SLC7A11 enhanced the sensitivity of CRC cells to SBRT via ferroptosis. SBRT diminished the ability of tumor cells to sustain oxidative stress by impeding the phosphorylation of JNK and c-Jun and the transcription of NRF2. Furthermore, sorafenib, which targets SLC7A11, exerted inhibitory effects on tumor growth when used in combination with SBRT. A phase II clinical trial confirmed that sorafenib combined with SBRT overcame the resistance of liver mCRC with high SLC7A11 expression by inducing ferroptosis. The combination of SBRT and sorafenib demonstrated favorable clinical effects and safety, making it a good option for patients with CRC liver metastasis. STATEMENT OF SIGNIFICANCE: A novel strategy using the combination of SBRT and sorafenib for the treatment of patients with CRC hepatic metastasis was investigated. This strategy overcomes the radiation therapy resistance of mCRC by inhibiting SLC7A11 expression and promoting ferroptosis.

Select updates from ASCO and ESMO 2024 for gastrointestinal cancer care

BACKGROUND

Gastrointestinal (GI) malignancies remain the culprit behind a substantial portion of cancer-related mortality worldwide, and outcomes for patients with advanced or metastatic GI cancers remain poor despite continued efforts to improve care. In 2024, the ongoing clinical trials to optimize and improve GI cancer care showcased progress in molecular diagnostics, systemic therapies, and localized treatment approaches, providing hope for continued progress toward improved patient outcomes.

MATERIALS AND METHODS

This review summarizes selected updates in GI cancer care from the 2024 ASCO and ESMO Annual Meetings, including both positive and negative trials that, while not universally practice-changing, contribute to shaping GI cancer care, clinical management, or address key questions in the field. The selected trials cover early detection and diagnostic advances, perioperative management, metastatic disease management, and immune checkpoint inhibitor (ICI)'s emerging role in GI cancer.

RESULTS

Various clinical trials in perioperative management and their results continue to reshape or strengthen the current treatment paradigms. The use of ICIs for microsatellite instability-high colorectal cancer (CRC) presented a notable advancement with the potential to improve patient outcomes. Localized treatments such as thermal ablation appear to benefit some patients with CRC and liver metastases.

CONCLUSIONS

The collection of trial results presented at the 2024 ASCO and ESMO Annual Meetings denote the ongoing efforts of the medical and scientific community for optimizing GI cancer care. The ongoing efforts of the GI cancer research and patient community provide hope for continued progress toward improved patient outcomes and new standards of care.

Management of Oligometastatic Colorectal Cancer

The management of oligometastatic colorectal cancer differs from the treatment of metastatic colorectal cancer, and it is essential that those who treat oligometastatic disease be familiar with the treatment options for these patients. Although definitive treatment is often surgical, there are situations where local therapies such as SBRT or ablative techniques may better serve the patient. Adjuvant therapy should be provided to all patients, and neoadjuvant chemotherapy should be considered as well. The role of immunotherapy is currently limited due to the lack of clinical trials in this area.

4D-MRI assisted stereotactic body radiation therapy for unresectable colorectal cancer liver metastases

This study evaluated the feasibilities and outcomes following four-dimensional magnetic resonance imaging (4D-MRI) assisted stereotactic body radiation therapy (SBRT) for unresectable colorectal liver metastases (CRLMs). From March 2018 to January 2022, we identified 76 unresectable CRLMs patients with 123 lesions who received 4D-MRI guided SBRT in our institution. 4D-MRI simulation with or without abdominal compression was conducted for all patients. The prescription dose was 50-65 Gy in 5-12 fractions. The image quality of computed tomography (CT) and MRI were compared using the Clarity Score. Clinical outcomes and toxicity profiles were evaluated. 4D-MRI improved the image quality compared with CT images (mean Clarity Score: 1.67 vs 2.88, P < 0.001). The abdominal compression reduced motions in cranial-caudal direction (P = 0.03) with two phase T2 weighted images assessing tumor motion. The median follow-up time was 12.5 months. For 98 lesions assessed for best response, the complete response, partial response and stable disease rate were 57.1 %, 30.6 % and 12.2 %, respectively. The local control (LC) rate at 1 year was 97.3 %. 46.1 % of patients experienced grade 1-2 toxicities and only 2.6 % patients experienced grade 3 hematologic toxicities. The 4D-MRI technique allowed accurate target delineation and motion tracking in unresectable CRLMs patients. Favorable LC rate and mild toxicities were achieved. This study provided evidence for using 4D-MRI assisted SBRT as an alternative treatment in unresectable CRLMs.