[Molecular biology of the clear cell renal cell carcinoma: principles for a selective treatment]

An Italian multicenter retrospective real-life analysis of patients with brain metastases from renal cell carcinoma: the BMRCC study

BACKGROUND

The treatment of patients with brain-spread renal cell carcinoma (RCC) is an unmet clinical need, although more recent therapeutic strategies have significantly improved RCC patients' life expectancy. Our multicenter, retrospective, observational study investigated a real-world cohort of patients with brain metastases (BM) from RCC (BMRCC).

PATIENTS AND METHODS

A total of 226 patients with histological diagnosis of RCC and radiological evidence of BM from 22 Italian institutions were enrolled. Univariate and multivariate models were performed to investigate the impact of clinicopathological features and multimodal treatments on both overall survival (OS) from the BM diagnosis and intracranial progression-free survival (iPFS).

RESULTS

The median OS from the BM diagnosis was 18.8 months (interquartile range: 6.2-43 months). Multivariate analysis confirmed the following as positive independent prognostic factors: a Karnofsky Performance Status >70% [hazard ratio (HR) = 0.49, 95% confidence interval (CI) 0.26-0.92, P = 0.0026] and a single BM (HR = 0.51, 95% CI 0.31-0.86, P = 0. 0310); in contrast, the following were confirmed as worse prognosis factors: progressive extracranial disease (HR = 1.66, 95% CI 1.003-2.74, P = 0.00181) and only one line of systemic therapy after the BM occurrence (HR = 2.98, 95% CI 1.62-5.49, P = 0.029). Subgroup analyses showed no difference in iPFS according to the type of the first systemic treatment [immunotherapy (IT) or targeted therapy (TT)] carried out after the BM diagnosis (HR = 1.033, 95% CI 0.565-1.889, P = 0.16), and revealed that external radiation therapy (eRT) significantly prolonged iPFS when combined with IT (10.7 months, 95% CI 4.9-48 months, P = 0.0321) and not when combined with TT (9.01 months, 95% CI 2.7-21.2 months, P = 0.59).

CONCLUSIONS

Our results suggest a potential additive effect in terms of iPFS for eRT combined with IT and encourage a more intensive multimodal therapeutic strategy in a multidisciplinary context to improve the survival of BMRCC patients.

Which biological pathways are responsible for the late appearance of brain metastases in renal cell carcinoma? Analysis of eight cases

Background:

Renal cell carcinoma (RCC) represents 1% of all cancers and its brain metastases amount to 8.1% of all metastatic tumors. Late brain metastases are defined as tumors that appear 10 years after diagnosis of the primary lesion. The objective of this work is to discuss which biological pathways are responsible for the late appearance of these metastases analyzing eight cases.

Case Description:

We report here eight cases of late brain metastases of RCC treated between 2018 and 2021. Patients consulted for different clinical complaints. Brain magnetic resonance imaging and computed tomography scan were performed on all patients. They were treated by complete surgical resection plus radiosurgery or by radiosurgery alone. The histology of most metastases showed clear cell RCC.

Conclusion:

In the presence of a patient with an intracranial tumor and a history of RCC with more than 10 years of evolution, the presence of late metastasis should always be considered. There are many theories described in the literature that try to explain the late appearance of brain metastases from RCC (low mitotic index, impaired immune system, cross talk, self-seeding, and among others).

KIF4A Promotes Clear Cell Renal Cell Carcinoma (ccRCC) Proliferation in vitro and in vivo

PURPOSE

To evaluate the expression in human clear cell renal cell carcinoma (ccRCC) tissues and explore the effects of kinesin family member 4A (KIF4A) on ccRCC progression.

METHODS

GEPIA was used to evaluate the mRNA levels of KIF4A in human ccRCC tissues from TCGA database, and Immunohistochemistry (IHC) assays were performed to assess its expression in human ccRCC tissues collected in our hospital. The clinical-pathological analysis was performed to explore the correlation with KIF4A expression. The effects of KIF4A on ccRCC cell proliferation were detected through colony formation and MTT assays. Finally, the effects of KIF4A on tumor growth were measured using a mice model.

RESULTS

Bioinformation results showed the expression of KIF4A mRNA was upregulated in ccRCC tissues and high expression of KIF4A was related with poor prognosis in ccRCC patients. We also found a high expression of KIF4A in human ccRCC tissues collected in our hospital. We also found its expression level was correlated with clinical characteristics, including T stage (P=0.035*) and lymphatic metastasis (P=0.028*). We further confirmed that knockdown of KIF4A suppressed cell proliferation in HTB-47 and CRL-1932 cells. Furthermore, KIF4A contributes to tumor growth of ccRCC cells in mice.

CONCLUSION

We found the abnormal high expression of KIF4A in human ccRCC tissues and demonstrated that KIF4A could serve as a tumor induction gene.