The omentum is a sheet of adipose tissue that surrounds the digestive organs. It is a common site of ovarian cancer metastasis. There are two ways in which ovarian cancer is known to metastasize. The first is passive dissemination. In this model, cancer cells detach from the tumor and are transported by the peritoneal fluid and ascites to their metastatic site. Ascite formation occurs due to VEGF signaling and blocking of lymphatic vessels. Cancer cells adhere to their metastatic site using matrix metalloproteinase (MMP), which is upregulated in cancer cells. MMP, along with other proteins, is also responsible for enhanced cell motility. The tumor cells then release cytokines such as interleukins to cause angiogenesis and a preferential microenvironment. The second model is hematogenous metastasis. Cancer cells undergo intravasation at the primary tumor site and extravasation at a distance metastatic site. The cancer cells target their metastatic site using cancer associated fibroblasts (CAFs). CAFs at the primary tumor site secrete proteins that upregulate pathways that promote cell motility in ovarian cancer cells. At the metastatic site, adipocytes and macrophages form a favorable tumor microenvironment.
Yeung TL, Leung CS, Yip KP, Au Yeung CL, Wong ST, Mok SC. Cellular and molecular processes in ovarian cancer metastasis. A Review in the Theme: Cell and Molecular Processes in Cancer Metastasis. Am J Physiol Cell Physiol. 2015;309(7):C444-56.
Comments
suggestion
Combine some of the sentences such as "There are two ways in which ovarian cancer is known to metastasize. The first is passive dissemination. " Maybe try saying "There are two ways in which ovarian cancer is known to metastasize one of which is passive dissemination."
Suggestion
You could combine the first two sentences for better flow: "The omentum is a sheet of adipose tissue that surrounds the digestive organs and is a common (primary?) site of ovarian cancer metastasis." You could also introduce both methods first instead of one at a time: "There are two ways in which ovarian cancer is known to metastasize: passive dissemination and hematogenous metastasis. In passive dissemination...etc." Then you can talk about passive dissemination and then talk more about hematogenous metastasis. It might help for better organization :)
Suggestion
The paragraph was descriptive but some parts sounded narrative so it will be better if you do not use words like "then."