Colon cancer with isolated metastasis to the kidney at the time of initial diagnosis

Blood-borne metastases to the kidneys from solid tumors have received little attention in the medical literature because they usually occur in a setting of advanced systemic disease, and renal involvement is a elatively minor cause of symptoms. Although the frequency of metastases to the kidney in cancer patients is 7–13% in large autopsy series, incidental discovery of a renal metastasis as the first manifestation of a primary tumor is a very rare event. The most common primary malignancy to involve the kidney is bronchogenic carcinoma, followed by breast and gastrointestinal cancers. In this article, we report a patient with left colon cancer and isolated metastasis to the right kidney at the time of initial diagnosis. Left hemicolectomy and right nephrectomy were performed. Adjuvant systemic chemotherapy consisting of 5-fluorouracil (5-FU) and folinic acid (FA) was given. 5-FU and FA were stopped after four cycles because metastases to the lung and liver occurred about 3 mo after the surgery during adjuvant chemotherapy. Capecitabine was started. The patient died 9 mo after the discovery of the isolated renal metastasis. Nephrectomy is more for diagnostic clarification in the setting of synchronous primary because it has no effect on survival and its effect on quality of life is minimal; as seen in our case, the other organ metastases rapidly occur and the survival is limited. Nephrectomy may also compromise the choice of chemotherapy agents that require renal clearance, thus a careful evaluation of renal functions is necessary if a nephrectomy is performed. In the matter of a decreased renal clearance, the doses of these drugs should be decreased or the choice should be reevaluated.