title: Impact of histologic subtype and sarcomatoid transformation on metastasis in renal cell carcinoma: a single institute experience in 149 patients.
abstract: OBJECTIVE
  To compare the metastatic pattern and outcome of clear cell RCC (ccRCC) and papillary RCC (pRCC), and to assess the impact of sarcomatoid transformation on the disease spread and prognosis.
  
  
  METHODS
  This IRB-approved, HIPAA-compliant retrospective study included 149 consecutive patients (108 men; mean age 58 years; range 25-86) with metastatic RCC (ccRCC = 116, pRCC = 33), identified from imaging database. All available imaging studies and electronic records of these patients were reviewed to document pathological features, distribution and timing of metastasis, and survival. The metastatic pattern and survival was first compared between the ccRCC and pRCC groups, and then between those with and without sarcomatoid transformation; all 27 cases of sarcomatoid transformation occurred in the ccRCC group.
  
  
  RESULTS
  Metastases were noted at presentation in 62 (42%) and after median 13 months in the remaining 87 (58%) patients. Lymph nodes (134/149), lung (125/149), and bone (60/149) were the most common metastatic sites, which did not differ between the RCC subtypes. Pancreatic (p = 0.0014) and renal (p = 0.046) metastases were more common in ccRCC, lymphangitic spread (p = 0.0003) and peritoneal metastasis (p = 0.039) more common in pRCC. In ccRCC, sarcomatoid transformation was associated with high-grade tumors (p < 0.0001), more frequently demonstrated lymphangitic (p = 0.016), pleural (p = 0.0018), and peritoneal metastases (p = 0.0002), and had shorter metastasis-free survival and overall survival (log-rank test, p < 0.0001). In the absence of sarcomatoid transformation, ccRCC had longer metastasis-free interval (median 22 months compared to 6 months) (p = 0.0238) and overall survival (median survival 48 months vs. 25 months) (p = 0.0193) compared to pRCC.
  
  
  CONCLUSIONS
  Histologic subtype, as well as the presence of sarcomatoid transformation, affects the metastatic pattern and metastasis-free survival of RCC. In the absence of sarcomatoid transformation, ccRCC has a better outcome than pRCC.
authors: Department of Imaging, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA, 02215, USA. Sreeharsha_Tirumani@DFCI.HARVARD.EDU.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA. Sreeharsha_Tirumani@DFCI.HARVARD.EDU.
authors: Sree Harsha
authors: SH
authors: Tirumani
authors: Department of Radiology, Brigham and Women's Faulkner Hospital, Harvard Medical School, 1153 Centre Street, Boston, MA, 02130, USA.
authors: Daniel
authors: D
authors: Souza
authors: Department of Imaging, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA, 02215, USA.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors: Katherine M
authors: KM
authors: Krajewski
authors: Department of Imaging, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA, 02215, USA.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors: Jyothi P
authors: JP
authors: Jagannathan
authors: Department of Imaging, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA, 02215, USA.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors: Nikhil H
authors: NH
authors: Ramaiya
authors: Department of Imaging, Dana Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA, 02215, USA.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors: Atul B
authors: AB
authors: Shinagare
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D012509:Sarcoma / Q000401:mortality / Q000473:pathology*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media
keywords: Clear cell renal cell carcinoma; Metastasis; Papillary renal cell carcinoma; Sarcomatoid renal cell carcinoma; Survival