Does postoperative radiation therapy impact survival in non-metastatic sarcomatoid renal cell carcinoma? A SEER-based study.
BACKGROUND
The effect of adjuvant radiation therapy on survival in sarcomatoid renal cell carcinoma (sRCC) with no evidence of distant metastasis remains unclear.


METHODS
Subjects diagnosed with non-metastatic sRCC were identified using the Surveillance Epidemiology and End Results (SEER) (2004-2012) database and divided into groups based on their surgical treatment (ST): no surgery or radiation therapy (NSR); partial nephrectomy (PNE); radical nephrectomy with ureterectomy and bladder cuff resection (RNE + UE + BLAD); and radical nephrectomy (RNE). Certain radical nephrectomy cases also received adjuvant external-beam radiation therapy (RNE + RAD). The Kaplan-Meier method was used to estimate overall survival (OS). A multivariable competing risks regression analysis was used to calculate disease-specific survival (DSS) probability and to determine factors associated with cause-specific mortality (CSM).


RESULTS
A total of 408 patients were included in this study. The 5-year OS and predicted DSS were significantly higher in the patients who underwent STs (i.e., PNE, RNE + UE + BLAD, RNE, and RNE + RAD) (20.1-54.0 and 20.1-59.9 %, respectively) than in the NSR group (9.0 and 11.6 %, respectively) (P < 0.001). ST was independently associated with a decreased CSM (P < 0.0001). No significant differences in OS or the 1-, 3-, or 5-year DSS probabilities between the RNE and RNE + RAD groups were observed. RNE + RAD was not significantly associated with a decrease in 1-year CSM [subhazard ratio (SHR) 0.95; 95 % CI 0.23-3.96; P = 0.947].


CONCLUSIONS
Adjuvant external-beam radiation therapy did not increase OS in non-metastatic sRCC patients.
Department of Urology, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany. okyaz.eminaga@uk-koeln.de.
Okyaz
O
Eminaga
Department of Urology, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany.
Ilgar
I
Akbarov
Department of Urology, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany.
Sebastian
S
Wille
Department of Urology, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany.
Udo
U
Engelmann
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods; D018714:Radiotherapy, Adjuvant / Q000401:mortality; D012044:Regression Analysis; D018426:SEER Program; D015996:Survival Rate; D014513:Ureter / Q000601:surgery; D001743:Urinary Bladder / Q000601:surgery; D055815:Young Adult
Disease-specific survival; Outcome; Radiation therapy; Renal cell carcinoma; SEER; Sarcomatoid renal cell carcinoma