Download Lung cancer metastasis

Kidney cancer metastasis
Kidney cancer (also known as renal cell carcinoma) is one of the five or six most common sites of origin of
metastatic cancer deposits in bone. 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 presents only when a
metastasis develops. Hematuria is also a common sign, but small amounts of blood in the urine cannot be
detected without a urinalysis 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.
Pain is the most common presenting symptom. Pathological fracture 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. An occasional
patient may have hypertesion from the tumor affecting the renin-angiotensin pathway.
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 particualr 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 at presentation have an unfavorable prognosis. Radiation is not very effective in palliating this
lesion, and no conventional chemotherapy is available. Treatment with interferon is under investigation.
All patients should be started and maintained on bisphosphonates as soon as a diagnosis of metastasis to
bone is confirmed. The average survival after the diagnosis of metastasis to bone is about 12 - 18 months.
However, a few selected cases have been associated with prolonged survival with appropriate treatment.
Patients who present with a SINGLE bone metastasis, whose primary tumor is resected with negative
margins, may be treated with curative intent. This means these patients have a chance for a cure, and
“palliative” care is not appropriate in these special cases. The prognosis is even more favorable if there has
been a prolonged period between the treatment of the primary tumor and the discovery of the metastasis.
Kidney cancer is one of the few types of metastatic adenocarcinoma that may be cured by surgery.
Physicians unfamiliar with these recent developments in the treatment of this disease should consider
referring the patient to a regional or national cancer center. When there are several sites of bone metastasis,
treatment folows general principles. Orthopedic stabilization of weakened bones should be done promptly,
before fractures can occur. Patients should receive complete treatment according to their wishes and the
extent of the disease. Orthopaedic stabilization of actual or impending pathological fractures should not be
withheld unless the patient cannot tolerate anaesthesia or would definitely not be benefited by surgery. The
pain relief from stabilization of damaged bones may warrant surgical treatment even if the patient cannot
enjoy a functional benefit, such as increased walking ability.