Adrenal metastasis in renal cell carcinoma: A recommendation for adjustment of the TNM staging system

Therapeutic options for different metastatic sites arising from renal cell carcinoma: A review

Renal cell carcinoma (RCC) stands among the top 10 malignant neoplasms with the highest fatality rates. It exhibits pronounced heterogeneity and robust metastatic behavior. Patients with RCC may present with solitary or multiple metastatic lesions at various anatomical sites, and their prognoses are contingent upon the site of metastasis. When deliberating the optimal therapeutic approach for a patient, thorough evaluation of significant risk factors such as the feasibility of complete resection, the presence of oligometastases, and the patient's functional and physical condition is imperative. Recognizing the nuanced differences in RCC metastasis to distinct organs proves advantageous in contemplating potential treatment modalities aimed at optimizing survival outcomes. Moreover, discerning the metastatic site holds promise for enhancing risk stratification in individuals with metastatic RCC. This review summarizes the recent data pertaining to the current status of different RCC metastatic sites and elucidates their role in informing clinical management strategies across diverse metastatic locales of RCC.

FDG PET/CT in detection of adrenal metastasis in patients with renal cell carcinoma

AIM

Adrenal metastasis in renal cell carcinoma (RCC) is uncommon. The present study was aimed to evaluate the role of fluoro-deoxy-glucose positron emission tomography (FDG PET)/computed tomography (CT) in the detection of adrenal metastasis in patients with RCC.

MATERIALS AND METHODS

A total of 9 FDG PET/CT scans were performed in 4 patients (3 males, 1 female; median age: 53.5 years, range: 52-73 years). Of 9 PET/CT scans, 2 scans were done for initial staging, 2 for restaging, and 5 for evaluation of treatment response. PET/CT image interpretation and analysis was performed qualitatively (visually) and semiquantitatively. Absence of uptake in postchemotherapy PET/CT scan was considered as complete response and a fall in SUV by more than 50% of baseline value, as significant response.

RESULTS

Patients 1 and 2 underwent staging FDG PET/CT. Patient 1 had undergone left radical nephrectomy 13 years back for left-sided RCC. Current FDG PET/CT revealed appearance of right RCC with adrenal metastasis. PET/CT of patient 2 demonstrated right adrenal and distant metastases. PET/CT done for restaging in patient 3, revealed right adrenal and abdominal lymph nodal metastasis. In patient 4, PET/CT revealed solitary adrenal metastasis. Magnetic resonance imaging findings were consistent with adrenal metastasis in this patient. Patient 1 received sunitinib and interferon chemotherapy along with radiotherapy and showed partial response on PET/CT scans done at 6, 17, 23, and 33 months from the initial study. PET/CT of patient 3 demonstrated the progression of disease (nonresponder).

CONCLUSION

FDG PET/CT appears to be useful for staging, treatment response evaluation, and recurrence detection in patients with RCC having adrenal metastasis.

[Operative treatment of renal cell carcinoma]

Renal cell carcinoma represents the fifth most frequent malignant tumor in humans. At the time of diagnosis, 20% of the patients already manifest metastases. A further 20-30% of the patients develop systemic metastases in the postoperative course. Despite continued advances in pharmacological treatment options, cancer surgery tailored to the individual tumor findings constitutes the only curative treatment option.

Should ipsilateral solitary adrenal involvement in renal cell carcinoma be staged as M1?

OBJECTIVE

In 2009, the TNM classification of malignant tumors was revised, and the renewal of the T2-4 stage in renal cell carcinoma was adopted. To date, however, the staging of ipsilateral solitary adrenal involvement in renal cell carcinoma has not been sufficiently evaluated.

METHODS

We retrospectively reviewed the adrenal involvement in renal cell carcinoma among 1033 patients admitted to the Department of Urology at Hamamatsu University Hospital, Japan, and affiliated hospitals between 1978 and 2007.

RESULTS

We identified 23 of the 1033 patients (2.2%) with adrenal involvement in renal cell carcinoma. In renal cell carcinoma patients with adrenal involvement, a tendency for a high histological grade of tumor and lower overall survival (P< 0.0001) was observed. Ipsilateral solitary adrenal involvement was detected in 4 of the 23 patients (15%), whereas 2 of the 23 (9%) had direct invasion of the adrenal gland. All tumors in the 14 patients without ipsilateral solitary adrenal involvement and recurrent adrenal tumors were classified as Stage IV. The TNM classification of the four renal cell carcinoma patients with ipsilateral solitary adrenal involvement was determined to be either pT3N0M0 or pT1-3N0M1. Among the four patients with ipsilateral solitary adrenal involvement, three patients had recurrent tumors, despite complete surgical resection. Two of these patients died of metastatic renal cell carcinoma after 2 and 10 years of radical nephrectomy, respectively, whereas one was still alive with cancer 3 years after the initial radical nephrectomy. The fourth had no recurrence of renal cell carcinoma, but did develop synchronous gall bladder cancer (pT2N0M0) and bile duct cancer (pT2N0M0).

CONCLUSIONS

Adrenal involvement in primary renal cell carcinoma was observed more frequently in patients with advanced tumor stages. In the TNM classification system, we propose that ipsilateral solitary adrenal involvement in renal cell carcinoma should be staged as M1.

Management of the adrenal gland during partial nephrectomy

PURPOSE

Nephron sparing surgery is an increasingly used alternative to Robson's radical nephroadrenalectomy. The indications for adrenalectomy in patients undergoing partial nephrectomy are not clearly defined and some surgeons perform it routinely for large and/or upper pole renal tumors. We analyzed initial management and oncological outcomes of adrenal glands after open partial nephrectomy.

MATERIALS AND METHODS

Institutional review board approval was obtained for this study. During partial nephrectomy the ipsilateral adrenal gland was resected if a suspicious adrenal nodule was noted on radiographic imaging, or if intraoperative findings indicated direct extension or metastasis.

RESULTS

Concomitant adrenalectomy was performed in 48 of 2,065 partial nephrectomies (2.3%). Pathological analysis revealed direct invasion of the adrenal gland by renal cell carcinoma (1), renal cell carcinoma metastasis (2), other adrenal neoplasms (3) or benign tissue (42, 87%). During a median followup of 5.5 years only 15 patients underwent subsequent adrenalectomy (0.74%). Metachronous adrenalectomy was ipsilateral (10), contralateral (2) or bilateral (3), revealing metastatic renal cell carcinoma in 11 patients. Overall survival at 5 years in patients undergoing partial nephrectomy with or without adrenalectomy was 82% and 85%, respectively (p = 0.56).

CONCLUSIONS

Adrenalectomy should not be routinely performed during partial nephrectomy, even for upper pole tumors. We propose concomitant adrenalectomy only if a suspicious adrenal lesion is identified radiographically or invasion of the adrenal gland is suspected intraoperatively. Using these criteria adrenalectomy was avoided in more than 97% of patients undergoing partial nephrectomy. Even using such strict criteria only 13% of these suspicious adrenal nodules contained cancer. The rarity of metachronous adrenal metastasis and the lack of an observable benefit to concomitant adrenalectomy support adrenal preservation during partial nephrectomy except as previously outlined.

Invasion of renal sinus fat is not an independent predictor of survival in pT3a renal cell carcinoma

OBJECTIVE

To clarify the significance of the location of extrarenal tumour extension of renal cell carcinoma (RCC) as in the 2002 Tumour-Nodes-Metastasis classification. Renal cortical tumours with perirenal fat invasion (PFI) or sinus fat invasion (SFI) are consolidated within the pT3a grouping; tumours with SFI are close to the renal veins, lymphatics and the collecting system. This might carry a worse prognosis for disease-specific survival (DSS), but reports are limited and contradictory.

PATIENTS AND METHODS

We retrospectively reviewed 1244 patients treated with nephrectomy from 1988 to 2007, to identify patients with pT3a renal tumours. They were classified as having PFI or SFI. Kaplan-Meier analysis and Cox proportional hazards regression models were used to assess predictors of survival.

RESULTS

The 230 patients who met the inclusion criteria had a median follow-up of 24 months. SFI was found in 63 (27.4%) patients and was associated with a worse 5-year DSS than the 167 (72.6%) with PFI (62.5% vs 75.0%; log rank P = 0.022). On univariate analysis, diameter (hazard ratio, HR 1.1), nuclear grade (HR 4.5), margin status (HR 5.8), lymph node metastases (HR 6.4), and systemic metastases (HR 15.4) were significant for DSS. In a multivariate model, only nuclear grade (HR 3.1), margin status (HR 8.9) and systemic metastases (HR 9.8) were independent predictors.

CONCLUSION

Patients with renal tumours with SFI are more likely to die from RCC than those with PFI. However, in the present patients the presence of SFI was not an independent predictor of DSS.

Location of Extrarenal Tumor Extension Does Not Impact Survival of Patients With pT3a Renal Cell Carcinoma

PURPOSE

The current TNM classification for pathological pT3a renal cell carcinoma includes patients with perinephric or sinus fat invasion, suggesting that the prognoses are similar for these pathological findings. However, sinus fat invasion was proposed by some investigators to be an independent predictor of inferior cancer specific outcome following surgical treatment. To assess and improve the predictive ability of the current pT3a primary tumor classification we evaluated the prognostic significance of location of extrarenal tumor extension on cancer specific survival following surgery.

MATERIALS AND METHODS

The database of 3,470 patients at our institution who were treated for renal cell carcinoma from 1990 to 2006 was searched for those with pT3a tumors managed by partial or radical nephrectomy. Patients with nonrenal cell carcinoma histology, direct adrenal invasion or a followup of less then 6 months were excluded from analyses. The prognostic importance of all clinical and pathological variables was investigated using Cox proportional hazards regression.

RESULTS

A total of 365 patients with pT3a renal cell carcinoma and a mean followup of 33.5 months (range 6.1 to 158.6) met study inclusion criteria and they comprise the data set for this analysis. There was no difference in 5-year cancer specific survival between 166 patients (45.5%) with SF invasion and 199 (54.5%) with PF invasion only (50.8% and 54.1%, p = 0.782 respectively). On univariate analyses neither sinus fat invasion nor the location of extrarenal extension, assessed as perinephric fat vs sinus fat vs perinephric plus sinus fat, correlated with cancer specific survival following surgical treatment (HR 1.052, p = 0.783 and HR 1.072, p = 0.543, respectively). After adjusting for the effects of nodal and systemic metastases tumor grade and sarcomatoid differentiation remained independent predictors of renal cell carcinoma specific survival in our pT3a cohort of patients (HR 1.508, p = 0.003 and HR 1.810, p = 0.018, respectively).

CONCLUSIONS

In contrast to previously reported observations, in our cohort of surgically treated patients with pT3a renal cell carcinoma the location of extrarenal extension was not an important prognosticator of cancer specific mortality. Based on our findings we confirm that perinephric and/or sinus fat should be similarly subclassified in the primary tumor staging system.

Prognostic markers in renal cell carcinoma

PURPOSE OF REVIEW

This article reviews recent reports on prognostic markers in renal cell carcinoma.

RECENT FINDINGS

Inclusion in studies of larger cohorts of patients has yielded enhanced prognostic information from integrated pathological markers; the findings suggest that adjustment to the TNM (tumour-node-metastasis) system is warranted. A number of patient-related factors remain important prognostically, including performance status, C-reactive protein and thrombocytosis, but also immunological factors (e.g. expression of B7-H1 by renal cell carcinomas is associated with progression). Additional prognostic information may be derived from a range of molecular markers. Findings of gene array and methylation studies may yield independent prognostic information. Enhanced knowledge of signalling pathways has facilitated better understanding of underlying biology and prediction of response to treatment. Other genes involved in regulating hypoxia-inducible factor [e.g. genes encoding carbonic anhydrase-IX and PTEN (phosphatase and tensin homolog)] were reported to be prognostically important in renal cell carcinoma. Other markers independently predicted survival (e.g. thymidine-phosphorylase and survivin).

SUMMARY

The potential of molecular markers suggested by clinical research is encouraging. Knowledge of various pathways will facilitate creation of systems of biomarkers that are predictive of individual response to therapy. Useful biomarkers may have potential as therapeutic targets.

Redefining pT3 renal cell carcinoma in the modern era

BACKGROUND

The 2002 American Joint Committee on Cancer (AJCC) tumor classification for renal cell carcinoma (RCC) does not take into account concomitant venous invasion and extrarenal tumor extension (ERE). In the current study, the authors evaluated the prognostic significance of venous tumor thrombus (VTT) and its extent, the presence and location of ERE, and a combination of both features on survival after the surgical management of patients with pathologic T3 (pT3) RCC.

METHODS

With Institutional Review Board approval, the institutional nephrectomy database of 3470 patients treated at the University of Texas M. D. Anderson Cancer Center from 1990 to 2006 was searched for pT3 RCC patients who were treated with partial or radical nephrectomy. Patients with nonmetastatic, lymph node-negative RCC and a minimum follow-up of 6 months were included in the analysis.

RESULTS

A total of 419 patients with pT3N0/NxM0 RCC and a mean follow-up of 40.8 months met the study inclusion criteria. In multivariate Cox regression analyses, the 2002 AJCC primary tumor classification was not found to be an independent predictor of cancer-specific mortality. A total of 211 patients with ERE only (50.4%) and 72 patients with VTT only (17.2%) were found to have a similar risk of death from RCC (hazards ratio [HR] of 1.018; P = .957), whereas 136 patients harboring both features (32.5%) were found to be significantly more likely to die from RCC (HR of 2.660; P < .001). The authors proposed a new primary tumor classification in which they grouped patients with both ERE and VTT (which was found to be an independent predictor of cancer-specific survival) into a separate staging category, and demonstrated improved prognostic ability when compared with the 2002 AJCC classification (c indexes of 0.625 vs 0.580, respectively).

CONCLUSIONS

The prognostic accuracy of the 2002 AJCC pT3 tumor classification can be improved by subclassifying patients with ERE only and those with VTT only into a prognostic category that is separate from patients with both ERE and VTT.

Association between age and clinical characteristics of renal cell carcinoma in adult patients

AIM

To study the association between age and clinical characteristics of renal cell carcinoma in adult patients.

METHODS

Three hundred and ten patients with renal cell carcinoma were classified into three groups: <or=40 years group, 41-59 years group and >or=60 years group. The clinical characteristics of the three groups were compared to define the association.

RESULTS

The male/female ratio was 1.3/1, 2.0/1, 3.3/1 in the three groups, respectively, and a significant difference appeared when comparing the <or=40 years group to the >or=60 years group (P=0.010). The respective percentage of incidental renal cell carcinoma was 27.9%, 43.2%, 31.2%, and it was significantly higher in the 41-59 years group than the >or=60 years group (P=0.047). The incidence of poorly differentiated renal cell carcinoma decreased with age increasing (11.6% vs 5.2% vs 2.7%), and there was significant difference between the <or=40 years group and the >or=60 years group (P=0.038). In the <or=40 years group, the incidence of lymph node metastasis was 18.6%, which was significantly higher than the other two groups (P<0.05). The percentage of T3a tumors was lower in <or=40 years group and the percentage of T1-3aN0M0 tumors was significantly higher in the 41-59 years group.

CONCLUSIONS

The percentage of female patients decreases with increasing age. The higher percentage of incidental renal cell carcinoma leads to the higher percentage of T1-3aN0M0 tumors in middle-aged patients. The higher percentage of poorly differentiated renal cell carcinoma led to the higher incidence of lymph node metastasis and decreased percentage of T3aN0M0 tumors in younger patients.

Adrenocortical Tumorigenesis

Through the widespread use of imaging techniques with great sensitivity adrenal tumors are often diagnosed as an incidental finding. Although the majority of these adrenal lesions are benign and without evidence of endocrine activity or malignancy, hormone hypersecretion needs to be ruled out by specific tests. In addition to the classical forms of overt adrenocortical hypersecretion, it has become evident over the recent years that modest adrenocortical steroid autonomy as present in normokalemic primary aldosteronism and subclinical Cushing's syndrome is also associated with a significant morbidity. However, detection and differential diagnosis of these subtle changes in adrenal steroidogenesis can pose a diagnostic challenge to the clinician and is dependent on tests with reliable sensitivity and specificity. Regulation of adrenocortical development and growth, which results in clinical symptoms if disrupted, is dependent upon the distinct spatiotemporal expression of a variety of transcription factors as well as stimulation by extra-adrenal peptide hormones. Contributions to the elucidation of growth regulation of the adrenal cortex come from rare familiar syndromes associated with adrenocortical tumors, expression studies of adrenal tumor samples, in vitro studies on adrenocortical tumor cell lines, and mouse models displaying adrenal growth defects. In this review, we will summarize the important molecular aspects of adrenal tumorigenesis and highlight some prospects for clinical applications.