The new TNM staging for renal cell carcinoma: what and why the urologists want to know.

Transcription

1 The new TNM staging for renal cell carcinoma: what and why the urologists want to know. Poster No.: C-1132 Congress: ECR 2011 Type: Educational Exhibit Authors: Y. Y. Lim, A. Hattab, A. Bradley ; Manchester/UK, manchester/ UK Keywords: Kidney, CT, MR, Ultrasound DOI: /ecr2011/C Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 22

2 Learning objectives To discuss the changes to the TNM staging for renal cell carcinoma and the differences from the previous edition. To identify the correct TNM stage based on the radiological findings. To illustrate the findings that the urologists would want to know and how it would affect management. Background There have been significant advances in the treatment strategies for renal cell carcinoma, particularly in nephron sparing surgery. This has led to the recent revision of the TNM staging to reflect the advances in treatment and prognosis for renal cell carcinoma. The accurate use of a standardised system enables the urologists and oncologists in planning treatment, determine prognosis and facilitate discussion between different centres. The updated TNM (7th edition) staging is summarised in the table 1. Table 1 Summary of new TNM staging for renal cell carcinoma Tx Primary tumour cannot be assessed T0 No evidence of primary tumour T1 Tumour # 7cm in greatest dimension, limited to kidney T1a Tumour # 4cm in greatest dimension, limited to kidney T1b Tumour > 4cm but # 7cm in greatest dimension, limited to kidney T2 Tumour > 7cm in greatest dimension, limited to kidney Page 2 of 22

3 T2a Tumour > 7cm but # 10cm in greatest dimension, limited to kidney T2b Tumour > 10cm in greatest dimension, limited to kidney T3 Tumour extends into major veins or perinephric tissues but not into the ipsilateral adrenal gland and not beyond Gerota fascia T3a Tumour grossly extends into the renal vein or its segmental branches, or tumour invades perirenal &/or renal sinus fat but not beyond Gerota fascia T3b Tumour grossly extends into the vena cava below the diaphragm T3c Tumour grossly extends into the vena cava above the diaphragm or invades the wall of the vena cava T4 Tumour invades beyond Gerota fascia (including contiguous extension into the ipsilateral adrenal gland) Nx Regional nodes cannot be assessed N0 No regional lymph nodes metastasis N1 Metastases in regional lymph node(s) M0 No distant metastases M1 Distant metastases The main differences in the new TNM staging system in comparison with the previous edition are: the introduction of the T2b category for tumours confined to the kidney but measures more than 10cm. tumours involving the renal vein but not the IVC is now T3a (previously T3b). T3a would also include invasion of renal sinus fat and perinephric fat. tumours extending into the ipsilateral adrenal gland is now T4 disease. N1 category for regional lymph node metastases (previous N2 for more than 1 regional node). Page 3 of 22

4 The changes to the TNM staging were made to reflect cancer specific survival, as per studies published since the 2002 version. Involvement of the renal vein is now reclassified as T3a disease, differentiating it from extension into the vena cava. Tumour thrombus level has been shown to be an independent predictor of survival and studies support the changes made to the TNM staging with regards to venous extension [1-3]. Contiguous invasion of the adrenal gland from upper pole renal tumours has been shown to have a significantly worse survival, with prognosis similar to stage pt4 disease [4-6]. This has led to the classification of T4 for contiguous adrenal invasion. Imaging findings OR Procedure details A significant number of renal cell carcinoma are detected incidentally by ultrasound scan (figure 1). This would require further characterization and staging with CT scan. CT has been shown to be accurate in the staging of renal cell carcinoma [7]. Magnetic resonance imaging is generally reserved for assessing indeterminate masses and has been shown to be the most sensitive means of identifying tumour thrombus [8]. Page 4 of 22

5 Fig.: Figure 1. Solid mass in the upper pole on US. CT required for further characterization and staging (see figure 2). With regards to surgical treatment, nephron sparing surgery is generally recommended for tumours <4cm in diameter, with recurrence rate and long-term survival rates similar to radical nephrectomy [9]. This can be performed either open or laparoscopically. Useful information for the urologists would include position of the tumour and intrarenal extent. Surgery for tumours with full thickness parenchymal involvement will enter the renal sinus, with possible risk of a urinary leak from the collecting system. The presence of supernumery renal arteries (most commonly a lower pole accessroy artery) is also valuable information from an arterial phase study. Percutaneous cryoablation or radiofrequency ablation are alternative treatment for small tumours in which partial or open nephrectomy is undesirable or contraindicated. This would include patients with multiple comorbidities or a solitary kidney. Posterior tumours are preferred in cryoablation to lessen the risk of adjacent organ damage[10]. Page 5 of 22

6 Fig.: Figure 2. Upper pole T1aN0M0 lesion. This would be suitable for partial nephrectomy. Laparoscopic nephrectomy has become an established surgical procedure particularly in T1 and T2 disease, with a lower morbidity rate than open surgery [11]. Page 6 of 22

7 Fig.: Figure 3. T1bN0M0 tumour with a central location. This would not be suitable for a partial nephrectomy. Laparoscopic nephrectomy was performed on this patient. Page 7 of 22

8 Fig.: Figure 4. T2aN0M0 lesion for which a laparoscopic nephrectomy was performed. Radical open nephrectomy is generally recommended for T3-4 disease. Useful information for the urologists would include the vascular supply, invasion of adjacent structures (figure 9) and level of IVC thrombus (figures 5 to 8). Supradiaphragmatic (level 3) tumour thrombus extension (figures 7 and 8) would involve a combined thoracoabdominal approach. Page 8 of 22

9 Fig.: Figure 5. T3aN0M0. Right renal tumor with perinephric fat invasion and renal vein involvement (arrow) but not extending to IVC. Page 9 of 22

10 Fig.: Figure 6. T3aN0M0. MR scan demonstrating right renal tumour with tumour thrombus extending into the right renal vein (arrow) but not into the IVC. Page 10 of 22

11 Fig.: Figure 7. T3cN0M0. CT scan shows a left renal tumour with tumour thrombus extending to the level above the diaphragm. Surgery would involve a thoracoabdominal approach. Page 11 of 22

12 Fig.: Figure 8. T3cN0M0. MR scan demonstrating tumour thrombus in the IVC extending above the diaphragm. Page 12 of 22

13 Fig.: Figure 9. T4N0M0. Right renal carcinoma with invasion of the intercostal and psoas muscles. Lymph node may be involved in 10-25% with a lower five-year survival rate that is substantially lower than patients without lymph node involvement. Regional lymphadenectomy should be performed in conjunction with a radical nephrectomy. Page 13 of 22

14 Fig.: Figure 10. N1 disease. CT scan demonstrating a left renal tumour with a metastatic lymph node(arrow). Approximately 25% of patients have metastatic disease at presentation. Surgical resection in selected patients may produce some long-term-survival. Treatment options for these patients would include immunotherapy, chemotherapy and radiation therapy. Page 14 of 22

15 Fig.: Figure 11. M1 disease. CT scan demonstrating liver metastases in a patient with renal carcinoma. Page 15 of 22

16 Fig.: Figure 12. Bone window demonstrating a left femoral metastasis. Pitfalls Non-neoplastic condition such as a renal abscess may mimic a renal mass (figure 13). An appropriate clinical history should suggest the correct diagnosis. Needle aspiration and percutaneous drainage should be performed. Page 16 of 22

17 Fig.: Figure 13. CT demonstrating a left renal lesion. Patient was pyrexic and unwell. US guided aspiration confirmed a renal abscess. An oncocytoma is the commonest solid benign renal tumour accounting for approximately 5% of renal masses. A central stellate scar is described in a small proportion of cases (figure 14). Oncocytoma cannot be reliably distinguished from renal cell carcinoma on imaging. Page 17 of 22

18 Fig.: Figure 14. CT scan demonstrating a left renal mass with central low attenuation. Partial nephrectomy has confirmed an oncocytoma. Advanced transitional cell carcinoma of the pelvicalyceal system extends into the renal parenchyma in an infiltrative manner and distorts the normal architecture. The kidney may enlarge but retains its reniform shape, unlike RCC. Page 18 of 22

19 Fig.: Figure 15a. CT scan showed a left renal mass. Further image (Figure 15b) showed some thickening of the pelvicalyceal system. This was confirmed as a transitional cell carcinoma on histology. Page 19 of 22

20 Fig.: Figure 15b. CT scan in the same patient (see figure 15a) demonstrating slight thickening of the pelvicalyceal system. This was confirmed as a transitional cell carcinoma on histology. Conclusion The main differences in the new TNM staging system in comparison with the previous edition are: the introduction of the T2b category for tumours confined to the kidney but measures more than 10cm. tumours involving the renal vein but not the IVC is now T3a (previously T3b). T3a would also include invasion of renal sinus fat and perinephric fat. tumours extending into the ipsilateral adrenal gland is now T4 disease. N1 category for regional lymph node metastases (previous N2 for more than 1 regional node). Page 20 of 22

21 Accurate TNM staging serves as a guide to determining treatment and prognosis for patients with renal cell carcinoma. Correct interpretation and classification of the tumour would aid the urologists in determining further management in these cases. Personal Information University Hospital of South Manchester, Southmoor Road, Manchester M23 9LT. References 1. Martinez-Salamanca JI, huang WC, Millan I, et al. Prognostic impact of the 2009 UICC/AJCC TNM staging system for renal cell carcinoma with venous extension. Eur Urol Oct Wagner B, Patard JJ, Mejean A, et al. Prognostic value of renal vein and inferior vena cava involvement in renal cell carcinoma. Eur Urol Feb;55(2): Epub 2008 Aug Moinzadeh A, Libertino JA. Prognostic significance of tumor thrombus level in patients with renal cell carcinoma and venous tumor thrombus extension. Is all T3b the same? J Urol Feb;171(2 Pt1): Han KR, Bui MH, Pantuck AJ, et al. TNM T3a renal cell carcinoma:adrenal gland involvement is not the same as renal fat invasion. J Urol Mar;169(3): ; discussion Thompson RH, Leibovich BC, Cheville JC, et al. Should direct ipsilateral adrenal invasion from renal cell carcinoma be classified as pt3a? J Urol Mar;173(3): Thompson RH, Cheville JC, Lohse CM,et al. Reclassification of patients with pt3 and pt4 renal cell carcinoma improves prognostic accuracy. Cancer Jul 1;104(1): Johnson CD, Dunnick NR, Cohan RH, Illescas FF. Renal adenocarcinoma: CT staging of 100 tumors. AJR, Vol 148, Issue 1, Kallman DA, King BF, Hattery RR, Charboneau JW, Ehman RL, Guthman DABlute ML. Renal vein and inferior vena cava tumor thrombus in renal cell carcinoma:ct, US, MRI and venacavography. J Comput Assist Tomogr Mar-Apr;16(2): Novick AC. Laparoscopic and partial nephrectomy. Clin Cancer Res 2004;10:6322S-7S. 10. Allen BC, Remer EM. Percutaneous cryoablation of renal tumors:patient selection,technique, and postprocedural imaging. Radiographics July : ;doi: /rg Page 21 of 22

22 11. Ono Y, Hattori R, Gotoh M, et al. Laparoscopic radical nephrectomy for renal cell carcinoma:the standard of care already?curr Opin Urol 2005;15:75-8. Page 22 of 22