Clear Cell Sarcoma of Kidney : Treatment & Prognosis
Treatment: Clear cell sarcoma of kidney (CCSK) is an aggressive tumor that used to have uniformly dismal prognosis. Current treatment consists of surgery followed by chemotherapy and radiation. The addition of doxorubicin to a regimen of vincristine and actinomycin has reduced the overall mortality. With the current multimodality treatment approaches, the 5-yr survival rate has improved to 75-85%. Patients with Stage 1 disease have a 95% survival rate. CCSK has a tendency for late relapses (15-20% of cases) and skeletal metastases (especially skull) necessitating prolonged follow-up. Relapses may occur anywhere from 3 to 10 years after treatment and involve sites such as regional lymph nodes, bone, brain, lung, and liver. In contrast, recurrences of Wilms tumor almost always present within 2 years. Prognostic Factors: Four independent prognostic factors have been identified. 1) Treatment with doxorubicin: Inclusion of doxorubicin in chemotherapy regimens has greatly improved the prognosis in CCSK. 2) Patient age: Patients diagnosed between 2 to 4 years of age have better survival than those younger (<2 yrs) or older (> 4 yrs). 3) Tumor stage: Patients presenting at stage 1 have a 95% survival rate. For stage 2 and 3, the survival rate is about 75%. 4) Necrosis: The presence of necrosis is an adverse prognostic indicator. This image of CCSK, classic pattern, shows nests of ovoid, epithelioid, or spindled tumor cells separated by thin fibrous septa containing delicate vasculature. A moderate amount of clear intercellular matrix intervening between the tumor cells gives rise to the "clear cell" appearance.