Renal Cell Carcinoma With Tumor Thrombus: A Case Series in Puerto Rico

Renal cell carcinoma (RCC) is one of the most common types of kidney cancer. While RCC tends to present as a localized tumor, a notable proportion may present with distant metastasis. In some instances, RCC may also present with intravascular tumor extension, often called tumor thrombus (TT). Its presence confers a worse prognosis and has important implications for the tumor's staging and treatment. Despite extensive documentation of RCC TT in the US, limited data exists regarding its presentation, management, and outcomes in Puerto Rico (PR). This study aims to broaden the available information on RCC TT, emphasizing surgical management and outcomes. We also provide descriptive data on patient demographics and clinical presentation to improve decision-making among clinicians caring for Puerto Rican men and women.

In this single-center, retrospective study, we evaluated patients who underwent partial or total nephrectomy at Saint Luke's Episcopal Medical Center between 2018 and 2022. Data was abstracted from electronic health records (EHR). Patients without documented evidence of TT during the peri-operative period were excluded from the study. A total of 220 patient records were evaluated, of which 12 met the inclusion criteria for the study. Cases were categorized using the latest RCC TT guidelines. Central tendency measurements were used to describe the sample distribution. The mean was considered to make assumptions regarding the prevalent observations, and the median was considered to rule out possible outliers. Categorical data were evaluated using proportion analyses, including TT extension level and BMI variables. Fisher's exact test evaluated the association between the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade and TT extension level.

Most patients lacked TT-related symptoms. The most severe presenting symptom was a pulmonary embolism (8.3%). Hypertension (83.3%), BMI greater than 25 at the time of diagnosis (75%), and type 2 diabetes mellitus (66.7%) were the most common comorbid conditions within our cohort. Nearly 75% of patients underwent laparoscopic radical nephrectomy with TT resection. One left-sided level III case was managed by laparoscopic-assisted open radical nephrectomy with a right subcostal incision. There were zero intraoperative complications and two postoperative complications. The histopathological reports of all cases were consistent with clear cell carcinoma, and half of the cases (n=6) were WHO/ISUP G4. All patients are alive and free of disease.

RCC is a common renal neoplasm in PR that can present with intravascular tumor extension. Our findings do not establish a definitive association between BMI, tumor size, WHO/ISUP grading, and TT extension level. Our study shows that laparoscopic removal of RCC TT is a safe and effective approach. However, the generalizability of our findings is limited by the study's design and sample size. Future research should focus on identifying predictive markers, establishing effective screening protocols, and determining if our hybrid approach has comparable outcomes to the standard open approach.