Wednesday, December 9, 2009

Renal Cell Cancer

Renal cell cancers (RCC) rank as the approximately sixth most common site of origin of metastatic deposits in the skeleton, this tumor has several unique features that increase its significance. Metastatitc means spreading and when this happens, its normally termed as Stage IV cancer. The cancer is named after the primary site it discovered. When a patient has a metastasis and no site of origin can be found (a metastasis of unknown origin) the most likely site is the lung or kidney.

First, the metastatic deposits may occur many years after the primary tumor has been treated. This means a patient who seems to be cured after a RCC is removed from the kidney needs to be monitored for up to ten years for possible bone metastasis.

Second, RCC metastases may occur as a localised disease, from which an en bloc surgical resection of a solitary metastasis may render the patient free of cancer and offer hope for a cure. Non treatment could lead to the spreading of the disease.

Although the number of cases of this cancer is proportionally small, the tumor has a high avidity for bone and thus creates relatively large number of bone lesions. Patients are usually over 40, and the average age is around 55. Patients may have no other manifestation of cancer other than their painful bone lesion. Because the primary tumor can grow fairly large without creating local symptoms such as flank pain or a mass in the abdomen, kidney cancer often detected only when a metastasis develops. Hematuria or blood in urine is also a common sign, but small amounts of blood in the urine cannot be detected without a urinalysis.

Pain is the most common presenting symptom. Broken bone or fracture caused by the disease rarely occurs without a history of a few weeks or months of increasingly severe pain. In some cases the patient has tried to ignore or deny the symptoms. Sometimes a painful bone lesion is thought to be a "muscle pull" or a "sprain" and strong pain medicines are prescribed, allowing the patient to continue to tolerate very severe pain before the true nature of the problem is discovered. Systemic symptoms may also occur, such as hypercalcemia (the presence of abnormally high levels of calcium in the blood).

Kidney cancer metastasis most commonly affects the spine, ribs, pelvis, and proximal long bones. Kidney cancer may metastasize extremely late after the treatment of the primary lesion, up to ten years or more. Why the tumor seems to lay dormant for so long and then suddenly pop up in the bone is not known. Another unusual feature of this lesion is its extremely aggressive appearance and behavior in some cases. Lesions may be large and appear as a "blowout" of the particular bone involved. Kidney cancers are more likely to become "hideously large" than other lesions, due to their propensity to extend massively in the soft tissues surrounding the bone. Since the kidney is comprised of mostly blood vessels, kidney cancer metastases may also have a rich blood supply, and may bleed extensively (even audibly) after a simple biopsy. When you see a patient over age 40 with hematuria and a large blow-out bone lesion, think kidney cancer.

Kidney cancer with metastasis to bone can be a very aggressive tumor and patients with multiple bone lesions means an unfavorable prognosis. No conventional treatment is available for now. The average survival after the diagnosis of metastasis to bone is about 12 - 18 months.

In my case, there is no visible bone lesions symptoms and I hope it stays that way. Of course one way is to do a bone scan to confirm. I have enough to deal for now, so I will leave this out for the time being. So far I only get slight pain around the thigh bones once in a while. As I lost some muscles, even resting on my elbow on the thigh can be painful. This is most evident in my buttocks.

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