Introduction

We aimed to investigate clinical and pathological antitumor effects of presurgical axitinib for renal cell carcinoma (RCC) extending into inferior vena cava (IVC).

Methods

From March 1995 to June 2016, we treated consecutive 38 RCC patients with IVC thrombus in our hospital. Patients were divided into those receiving radical nephrectomy alone (control) and those receiving presurgical axitinib before planned radical nephrectomy (Neo-Axi). Patients’ background, clinicopathological parameters, and prognosis were compared between the control and Neo-Axi groups. In the Neo-Axi group, tumor responses were evaluated by RECIST v1.1 before and after axitinib including renal tumor and IVC thrombus. Fibrosis within IVC thrombus was evaluated by Azan staining, and interstitial fibrosis (IF) rates were compared between the control and Neo-Axi groups.

Results

The number of patients in the control and Neo-Axi groups were 30 and 8, respectively. There were no significantly differences in age, sex, thrombus level, metastatic disease, MSKCC risk classification between the control and Neo-Axi group. Axitinib-related adverse events were grade 3 hypertensions (n=3) and diarrhea (n=1). Median tumor responses in renal tumor and IVC thrombus were 22.3% and 41.1%, respectively. Median regression IVC thrombus was 15.5 mm. Median operation time and blood loss between the control and Neo-Axi group were significantly different (318 vs. 204 minutes, 2450 vs. 450 grams, respectively). One patient experienced perioperative death due to lung thrombosis in the control group. Pathological complete response (pT0) was obtained in one patient (12.5%) in the Neo-Axi group. Median interstitial fibrosis rate of IVC thrombus was significantly higher in the Neo-Axi group compared with the control group (8.7% and 3.4%, respectively, P=0.0021). Progression free survival between the control and Neo-Axi group were 13 and 33 months, respectively (P=0.060). Overall survival between the control and Neo-Axi group were 41 months and undefined, respectively (P=0.071).

Conclusions

Presurgical axitinib therapy enhanced tumor reduction accompanied by fibrosis, and may contribute surgical risk reduction. Presurgical axitinib therapy might be feasible option for RCC with IVC thrombus.

Funding

None