Early efficacy of stereotactic body radiation therapy combined with adoptive immunotherapy for advanced malignancies

Synergy between early-incorporation immunotherapy and extracranial radiotherapy in metastatic non-small cell lung cancer

Background

Combining radiotherapy (RT) and immunotherapy (IT) may enhance outcomes for metastatic non-small cell lung cancer (mNSCLC). However, data on the immunomodulatory effects of extracranial RT remains limited. This retrospective database analysis examined real-world practice patterns, predictors of survival, and comparative effectiveness of extracranial radioimmunotherapy (RT + IT) versus early-incorporation immunotherapy (eIT) in patients with mNSCLC.

Methods

Patients diagnosed with mNSCLC between 2004-2016 treated with eIT or RT + IT were identified in the National Cancer Database. Practice patterns were assessed using Cochrane-Armitrage trend test. Cox proportional hazards and Kaplan-Meier method were used to analyze overall survival (OS). Propensity score matching was performed to account for baseline imbalances. Biologically effective doses (BED) were stratified based on the median (39 Gy₁₀). Stereotactic body radiotherapy (SBRT) was defined as above median BED in ≤5 fractions.

Results

eIT utilization increased from 0.3% in 2010 to 13.2% in 2016 (P<0.0001). Rates of RT + eIT increased from 38.8% in 2010 to 49.1% in 2016 among those who received eIT (P<0.0001). Compared to eIT alone, RT + eIT demonstrated worse median OS (11.2 vs. 13.2 months) while SBRT + eIT demonstrated improved median OS (25 vs. 13.2 months) (P<0.0001). There were no significant differences in OS based on sequencing of eIT relative to RT (log-rank P=0.4415) or irradiated site (log-rank P=0.1606). On multivariate analysis, factors associated with improved OS included chemotherapy (HR 0.86, P=0.0058), treatment at academic facilities (HR 0.83, P<0.0001), and SBRT (HR 0.60, P=0.0009); after propensity-score multivariate analysis, SBRT alone showed improved OS (HR 0.28, P<0.0001).

Conclusions

Utilization of RT + eIT in mNSCLC is increasing. SBRT + eIT was associated with improved OS on propensity-score matched analysis. There were no significant differences in OS based on RT + eIT sequencing or site irradiated. Whether these observations reflect patient selection or possible immunomodulatory benefits of RT is unclear and warrants further study.

Combining stereotactic body radiation therapy with immunotherapy: current data and future directions

Stereotactic body radiation therapy (SBRT) offers excellent local control of early-stage non-small cell lung cancer (NSCLC), but there currently is a need for tolerable systemic therapy to address regional and distant disease progression. One potential option is immunotherapy, which in metastatic NSCLC has shown promise for sustained disease control in a subset of patients. There is also growing evidence for a clinical synergy between radiation and immunotherapy, with several ongoing trials studying the abscopal effect. This review summarizes the current data in the fast-changing field of immuno-radiation therapy, highlighting updates from recent clinical trials.

A comprehensive review of contemporary role of local treatment of the primary tumor and/or the metastases in metastatic prostate cancer

To provide an overview of the currently available literature regarding local control of primary tumor and oligometastases in metastatic prostate cancer and salvage lymph node dissection of clinical lymph node relapse after curative treatment of prostate cancer. Evidence Acquisition. A systematic literature search was conducted in 2014 to identify abstracts, original articles, review articles, research articles, and editorials relevant to the local control in metastatic prostate cancer. Evidence Synthesis. Local control of primary tumor in metastatic prostate cancer remains experimental with low level of evidence. The concept is supported by a growing body of genetic and molecular research as well as analogy with other cancers. There is only one retrospective observational population based study showing prolonged survival. To eradicate oligometastases, several options exist with excellent local control rates. Stereotactic body radiotherapy is safe, well tolerated, and efficacious treatment for lymph node and bone lesions. Both biochemical and clinical progression are slowed down with a median time to initiate ADT of 2 years. Salvage lymph node dissection is feasible in patients with clinical lymph node relapse after local curable treatment. Conclusion. Despite encouraging oncologic midterm results, a complete cure remains elusive in metastatic prostate cancer patients. Further advances in imaging are crucial in order to rapidly evolve beyond the proof of concept.