VHL loss reprograms the immune landscape to promote an inflammatory myeloid microenvironment in renal tumorigenesis.

Clear cell renal cell carcinoma (ccRCC) is characterized by dysregulated hypoxia signaling and a tumor microenvironment (TME) highly enriched in myeloid and lymphoid cells. Loss of the von Hippel Lindau (VHL) gene is a critical early event in ccRCC pathogenesis and promotes stabilization of HIF. Whether VHL loss in cancer cells affects immune cells in the TME remains unclear. Using Vhl WT and Vhl-KO in vivo murine kidney cancer Renca models, we found that Vhl-KO tumors were more infiltrated by immune cells. Tumor-associated macrophages (TAMs) from Vhl-deficient tumors demonstrated enhanced in vivo glucose consumption, phagocytosis, and inflammatory transcriptional signatures, whereas lymphocytes from Vhl-KO tumors showed reduced activation and a lower response to anti-programmed cell death 1 (anti-PD-1) therapy in vivo. The chemokine CX3CL1 was highly expressed in human ccRCC tumors and was associated with Vhl deficiency. Deletion of Cx3cl1 in cancer cells decreased myeloid cell infiltration associated with Vhl loss to provide a mechanism by which Vhl loss may have contributed to the altered immune landscape. Here, we identify cancer cell-specific genetic features that drove environmental reprogramming and shaped the tumor immune landscape, with therapeutic implications for the treatment of ccRCC.

Tumor volume reduction evaluated by cone beam computed tomography during stereotactic body radiotherapy for early stage non-small cell lung cancer.

BACKGROUND: We hypothesized that significant tumor volume reduction (TVR) occurs over the course of stereotactic body radiotherapy (SBRT) for early stage non-small cell lung cancer (NSCLC), and that TVR correlates with clinical outcomes. METHODS: We conducted a retrospective review of patients treated with SBRT for early stage NSCLC across two academic centers. For each patient, we contoured the tumor volume (TV) on cone beam computed tomography (CBCT) images obtained before each treatment fraction. We then calculated TVR based on the TV from the first and last days of treatment. We used log-rank tests to quantify differences in overall survival (OS), progression-free survival (PFS) and recurrence based on TVR. RESULTS: Data from 69 patients and a total of 73 treated tumors were analyzed. The median follow-up for survivors was 51.8 months (range, 6.9 to 80.0 months). The median TVR for the cohort was 10.1% (range, -5.7% to 43.5%). There was no significant difference in either OS (median 33.4 vs. 29.1 months, P=0.79) or PFS (median 26.3 vs. 12.3 months, P=0.43) for those with high TVRs (≥10.1%) vs. low TVRs (<10.1%), respectively. There was a trend toward superior 2-year PFS in the high TVR group (52.2% vs. 36.7%, P=0.062), but this effect diminished on longer follow-up (4-year PFS 31.9% vs. 26.7%, P=0.15). No associations were observed between TVR and local, regional or distant recurrence. CONCLUSIONS: We were not able to demonstrate that TVR is a reliable predictive imaging marker for stage I/II NSCLC treated with SBRT. Future studies with larger sample sizes are needed to clarify a potential relationship between TVR and early outcomes.