The curability of Metastases rests on three lines of clinical evidence: spontaneous regression, solitary metastases, and delayed metastases. The documentation of curable metastases is most common in hypernephroma and provides the setting to discuss the general problem: are metastases curable?
The recent publication of two monographs on the subject of spontaneous regression of cancer22,38 records the factual data. Of 176 cases of documented spontaneous regressions, 31 cases of hypernephroma were collected, 28 of which had pulmonary metastases.22 Regression followed nephrectomy in 22 of these patients. The definition of spontaneous regression of cancer which is offered as "partial or complete disappearance of malignant tumors in the absence of all treatment or in the presence of therapy which is considered inadequate to exert a significant influence on neoplastic disease." It is not synonymous with cure. As Goodwin has noted in this series, it is based on presumptive radiologic
Rubin P. Comment: Are Metastases Curable?. JAMA. 1968;204(7):612–613. doi:10.1001/jama.1968.03140200052016