Prognostic stratification in UPC: a role for assessing the value of conventional-dose and high-dose chemotherapy for unknown primary carcinoma

High-dose chemotherapy has been advocated by some investigators as a means to circumvent drug resistance, thereby improving treatment results in patients with solid tumors. For patients with unknown primary tumors, this hypothesis has only recently undergone limited testing. Two groups (one from the USA and one from Europe) have published their experience with higher doses of chemotherapy in the treatment of UPC. The results are not superior to those reported by other investigators using more standard doses of chemotherapy. Most importantly, chemotherapy trials for UPC are usually conducted in small populations made up of heterogeneous patient subsets with varying sensitivity to chemotherapy. It seems likely that progress in the management of patients with unknown primary cancers will occur as a result of efforts to improve the understanding of the natural history of this disease coupled with the assessment of novel agents targeted against specific biochemical abnormalities that will be demonstrated to be important in the development and maintenance of these malignancies.