Ever since Stephen Paget’s 1889 hypothesis, metastatic organotropism has remained one of cancer’s greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6β4 and α6β1 were associated with lung metastasis, while exosomal integrin αvβ5 was linked to liver metastasis. Targeting the integrins α6β4 and αvβ5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

Pancreatic ductal adenocarcinomas (PDAC) are highly metastatic with poor prognosis, mainly due to delayed detection. We hypothesized that intercellular communication is critical for metastatic progression. Here, we show that PDAC- derived exosomes induce liver pre-metastatic niche formation in naïve mice and consequently increase liver metastatic burden. Uptake of PDAC-derived exosomes by Kupffer cells caused transforming growth factor β secretion and upregulation of fibronectin production by hepatic stellate cells. This fibrotic microenvironment enhanced recruitment of bone marrow-derived macrophages. We found that macrophage migration inhibitory factor (MIF) was highly expressed in PDAC-derived exosomes, and its blockade prevented liver pre-metastatic niche formation and metastasis. Compared to patients whose pancreatic tumors did not progress, MIF was markedly higher in exosomes from stage I PDAC patients who later developed liver metastasis. These findings suggest that exosomal MIF primes the liver for metastasis and may be a prognostic marker for the development of PDAC liver metastasis.

ObjectiveTo analyze resectability and survival in patients with hilar cholangiocarcinoma according to a proposed preoperative staging scheme that fully integrates local, tumor-related factors. Summary Background DataIn patients with hilar cholangiocarcinoma, long-term survival depends critically on complete tumor resection. The current staging systems ignore factors related to local tumor extent, preclude accurate preoperative disease assessment, and correlate poorly with resectability and survival. MethodsDemographics, results of imaging studies, surgical findings, pathology, and survival were analyzed prospectively in consecutive patients. Using data from imaging studies, all patients were placed into one of three stages based on the extent of ductal involvement by tumor, the presence or absence of portal vein compromise, and the presence or absence of hepatic lobar atrophy. ResultsFrom March 1991 through December 2000, 225 patients were evaluated, 77% of whom were seen and treated within the last 6 years. Sixty-five patients had unresectable disease; 160 patients underwent exploration with curative intent. Eighty patients underwent resection: 62 (78%) had a concomitant hepatic resection and 62 (78%) had an R0 resection (negative histologic margins). Negative histologic margins, concomitant partial hepatectomy, and well-differentiated tumor histology were associated with improved outcome after all resections. However, in patients who underwent an R0 resection, concomitant partial hepatectomy was the only independent predictor of long-term survival. Of the 9 actual 5-year survivors (of 30 at risk), all had a concomitant hepatic resection and none had tumor-involved margins; 3 of these 9 patients remained free of disease at a median follow-up of 88 months. The rates of complications and death after resection were 64% and 10%, respectively. In the 219 patients whose disease could be staged, the proposed system predicted resectability and the likelihood of an R0 resection and correlated with metastatic disease and survival. ConclusionBy taking full account of local tumor extent, the proposed staging system for hilar cholangiocarcinoma accurately predicts resectability, the likelihood of metastatic disease, and survival. Complete resection remains the only therapy that offers the possibility of long-term survival, and hepatic resection is a critical component of the surgical approach.Cholangiocarcinoma is a rare disease, accounting for less than 2% of all human malignancies.1 Although the entire biliary tree is potentially at risk, tumors involving the biliary confluence or the right or left hepatic ducts (hilar cholangiocarcinoma) are most common and account for 40% to 60% of all cases. [2][3][4][5][6] Meaningful clinical experience in managing hilar cholangiocarcinomas has been limited to a few referral centers because of the infrequency with which they are encountered.Although resection has long been recognized as the most effective therapy for hilar cholangiocarcinoma, 7 the importance of partial hepatectomy an...

Patients who survive 10 years appear to be cured of their disease, whereas approximately one third of actual 5-year survivors succumb to a cancer-related death. In well-selected patients, there is at least a one in six chance of cure after hepatectomy for CLM. The presence of poor prognostic factors does not preclude the possibility of long-term survival and cure.