A simple 4-dimensional Euclidean embedding of a rectangular flat torus (more general than the square one) is as follows:

  
    
      
        (
        x
        ,
        y
        ,
        z
        ,
        w
        )
        =
        (
        R
        cos
        ⁡
        u
        ,
        R
        sin
        ⁡
        u
        ,
        P
        cos
        ⁡
        v
        ,
        P
        sin
        ⁡
        v
        )
      
    
    {\displaystyle (x,y,z,w)=(R\cos u,R\sin u,P\cos v,P\sin v)}
  where R and P are positive constants determining the aspect ratio.
A retrospective analysis showed a survival benefit for mitotane in addition to surgery when compared to surgery alone.The two most common regimens are cisplatin, doxorubicin, etoposide (EDP) + mitotane, and streptozotocin + mitotane. The FIRM-ACT trial demonstrated higher rates of response and longer progression-free survival with EDP + mitotane than with streptozotocin + mitotane. Prognosis
ACC, generally, carries a poor prognosis, with an overall 5-year survival rate of about 50%. Five-year disease-free survival for a complete resection of a stage I–III ACC is about 30%. The most important prognostic factors are age of the patient and stage of the tumor. Poor prognostic factors include mitotic activity, venous invasion, weight of 50 g or more, diameter of 6.5 cm or more, Ki-67/MIB1 labeling index of 4% or more, and p53 positive.In its malignancy, adrenocortical carcinoma is unlike most tumours of the adrenal cortex, which are benign (adenomas) and only occasionally cause Cushings syndrome. References


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