Sarcomatoid dedifferentiation fails to predict RCC survival
medwireNews: Sarcomatoid dedifferentiation does not independently predict survival in patients who have undergone surgery for the treatment of renal cell carcinoma (RCC), results from a matched-pair analysis indicate.
The results showed that although sarcomatoid dedifferentiation, at a cutoff of at least 10% spindle area occupation, was associated with adverse prognostic parameters and advanced disease at diagnosis, it did not independently predict prognosis.
However, the study researchers note that clinical pathologists often neglect to comment on the absence or presence and estimated percentage of sarcomatoid dedifferentiation in pathology reports, and this “is imperative” to fully understanding the prognostic role of sarcomatoid dedifferentiation.
The study involved 281 RCC patients with and 281 without sarcomatoid dedifferentiation who were matched, according to propensity scores, for age, gender, histologic subtype, tumor size, grade, pathologic tumor stage, nodal status, and M-stage.
Cancer-specific survival over a median follow-up period of 36.5 months did not differ significantly between the two groups, with 1-year rates of 79% for patients with sarcomatoid dedifferentiation and 83% for those without, and respective 5-year rates of 59% and 64%.
The factors found to be independently associated with cancer-specific survival for the whole group following multivariate analysis were metastatic dissemination at the time of surgery, pathologic tumor stage, nodal status, grade, and tumor size.
For patients with sarcomatoid dedifferentiation, the independent predictors were metastatic spread at the time of surgery, positive lymph nodes, pathologic tumor stage, and tumor size.
Tumor grade, however, was no longer an independent prognostic parameter. This implies that “when sarcomatoid areas exhibit high-grade nuclear features, further delineation between Furhman nuclear grades 3 and 4 is prognostically meaningless,” the team, led by Sabine Brookman-May (Ludwig-Maximilians University, Munich, Germany), comments in Clinical Genitourinary Cancer.
“These findings suggest that… [sarcomatoid dedifferentiation] might be a histomorphological expression of other adverse pathological parameters rather than representing an independent prognostic factor itself.”
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By Lucy Piper, Senior medwireNews Reporter