Radical nephrectomy and thrombectomy can effectively improve the prognosis of the 4% to 10% of patients with renal cell carcinoma (RCC) who develop venous tumor thrombus (VTT), according to a study published in Frontiers in Oncology. “After complete removal of the tumor and tumor thrombus, a 5-year survival rate of more than 50% can be achieved, while the 5-year survival rate is only about 10% when the resection is incomplete,” wrote the study authors.

However, deep invasive tumor thrombus (DITT), in which the tumor thrombus invades the venous wall, can significantly increase surgery difficulty and requires partial or segmental inferior vena cava resection. IT remains unclear whether DITT leads to poor prognosis in patients with RCC and VTT, the study authors noted.

 

Deep Invasive Tumor Thrombus Significantly Increased Surgical Difficulty for Patients With Renal Cell Carcinoma & Venous Tumor Thrombus

For their study, investigators evaluated the impact of DITT on the surgical difficulty and prognosis of patients with RCC with VTT. They retrospectively reviewed clinical data of 138 patients with non-metastatic RCC combined with VTT who had surgical treatment from January 2015-June 2020. Patients were divided into a DITT group (M=84) and non-invasive tumor thrombus (NITT) group (N=54). The study team used Chi-square, t-test, and Mann–Whitney U tests for categorical and continuous variables, respectively, and Kaplan–Meier plots to evaluate the influence of DITT. They conducted univariable and multivariable Cox regressions to establish independent prognostic factors, which they then assembled to make a nomogram to predict survival.

DITT significantly increased surgical difficulty for patients with RCC and VTT. This resulted in more surgical bleeding, longer operation time, longer postoperative hospital stay, higher proportion of perioperative blood transfusion, higher proportion of open surgery, and a higher proportion of postoperative complications.

Deep Invasive Tumor Thrombus an Independent Risk Factor for Worse Prognosis

DITT (HR=2.781) was an independent risk factor for worse prognosis, with sarcoma-like differentiation, tumor thrombus invasion, low hemoglobin, and pathological type found to be independent prognostic factors. Combining all these factors, the nomogram showed powerful prognostic ability with a C-index of 78.8%.

“[DITT] significantly increased the difficulty of surgeries for patients with renal cell carcinoma with venous tumor thrombus, and may lead to poor prognosis,” the study authors wrote.