Ano ang kidney cancer?

ANG kidney cancer ay karaniwang tumatama sa mga kalalakihan kaysa kababaihan. Ang paninigarilyo at ang labis na exposure sa cadmium ang pinaniniwalaang dahilan ng pagkakaroon ng sakit na ito. Mataas ang incidence ng kidney cancer sa Europe partikular sa Denmark at ang pinakamababang incidence ay sa Japan. Sa United Kingdom, tinatayang may 3,600 ang itinatalang kaso ng kidney cancer at dalawang porsiyento ng mga kasong ito ay malignant o malubha na. 

Ang tumor ay maaaring tumubo sa alinmang bahagi ng renal tissue – sinasakop ang one quarter ng buong kidney, one third ng upper pole at one third naman ng lower pole. Ang tumor ay karaniwang solid at nag-eexpand sa renal tissue tungo sa gitnang bahagi ng necrosis o cystic degeneration at sa iba pang haemorrhagic areas. 

Occasionally a tumor may arise from the lining cells of the proximal convoluted tubule. Microscopically they are adenocarcinomas composed of characteristic clear      cells although the degree of defferentation can vary from a well-differentiated tumor to a highly anaplastic appearance. 

Pinipinsala ng tumor ang paligid ng kidney at maaaring tumubo sa renal vein at hanggang sa inferior vena cava (IVC). Apektado ng pagkalat ng lymph node ang renal hilar nodes hanggang sa para-aortic chain. Blood borne metastases characteristically go to the lung and bone although many other sites including skin, central nervous system and liver are also recognized. 

Spontaneous regression of metastases, typically lung deposits monitored on chest x-ray, is often referred to in the context of renal cell cancer. While such events undoubtedly occur the true incidence is extremely low, the verified incidence being around seven percent of patients with metastatic disease. Spontaneous regression of the primary tumor is virtually unknown.