Tumour Evolution and Seed and Soil Mechanism in Pancreatic Metastases of Renal Cell Carcinoma

Abstract

In metastatic renal cell carcinoma, pancreatic metastases can appear in two clinical manifestations: (a) very rarely as isolated pancreatic metastases and (b) in the context with multi-organ metastatic disease. Both courses are characterised by rare, unusual clinical features. For isolated pancreatic metastases, the literature shows no effect on survival in all 11 publications that examined the effect of singular versus multiple pancreatic metastases; a lack of effect on survival time was also present in all 8 studies on pancreatic metastases size, in 7 of 8 studies on the influence of disease-free interval (DFI), and in 6 of 7 studies on the influence of synchronous versus metachronous metastases. In multi-organ site metastases observations, on the other hand, all five available references showed significantly better results in patients with concurrent pancreatic metastases compared to those without pancreatic metastases, although the total number of affected organs in the pancreatic metastases cohort was larger. Tumour volume-dependent risk factors thus remain surprisingly ineffective in both groups, which contradicts the usual behaviour of solid tumours. The reasons for this unusual behaviour and possible relations to tumour evolution and the hypothesis of an influence of a seed and soil mechanism in the occurrence of pancreatic metastases in metastatic renal cell carcinoma are discussed.

Tumor-Associated Macrophages (TAMs) in Colorectal Cancer (CRC): From Mechanism to Therapy and Prognosis

“…The components of the tumor microenvironment include all of the nonmalignant stroma cells inside the tumor other than the tumor cells, including fibroblasts, endothelial cells, immune cells, and platelets [5,6]. Paget proposed the "seed and soil" theory in 1889 and conducted an indepth analysis of the molecular characteristics of "seeds" (cancer cells) [7][8][9][10][11]. By studying the "soil" formed by cancer cells and host immune cells, scientists found that immune cells usually bind to cancer cells and obtain specific biological phenotypes via interactions with them.…”

Metastatic Renal Cell Carcinoma to Pancreas: Case Series and Review of the Literature

“…The mechanism of isolated PM in RCC involves a particular “seed and soil” pathway that explains the selective development of metastases in the pancreas by embolized cells from the primary tumor. This specific metastatic mechanism creates a frame for uniform distribution of metastatic lesions across the pancreas, independent of the RCC site, and similar outcomes in singular versus multiple, synchronous versus metachronous isolated PM [ 10 , 11 , 12 , 13 , 14 ].…”

Case Report: Pancreatic metastasis of renal cell carcinoma 16 years after nephrectomy

“…As a distinct case of RCC, isPMRCC has a clinical hallmark of confinement to the pancreas while the other organs are left unaffected for a long duration. This kind of organotropism may be explained based on seed and soil theory, according to which the metastatic process is determined by the interaction between the tumor cells (seed) and the host organism (soil) ( 17 , 18 ). Research on microRNA has identified that miRNAs regulate the metastatic potential of tumor cells and explain the seed and soil concept biochemically ( 17 , 19 ).…”