Final answer:
Early metastasis in esophageal malignancy is caused by cancer cells traveling from the primary tumor through the bloodstream, potentially settling in the brain, lungs, bones, and liver. Abnormal cell surface glycoproteins and highly-permeable tumor vasculature facilitate this process, along with the activity of matrix metalloproteinases (MMPs) that promote invasion and metastasis.
Step-by-step explanation:
Mechanism Underlying Early Metastasis in Esophageal Malignancy:
The mechanism underlying early metastasis with esophageal malignancy involves cancer cells traveling from the primary tumor through the bloodstream to form new cancer at distant sites, a process known as metastasis. The blood carries these cancer cells to other parts of the body, where they may grow in particular organs that are common sites for metastases: the brain, lungs, bones and liver. Malignant tumors have the ability to grow beyond their boundaries and shed cells that can enter the bloodstream, thus causing metastasis.
Esophageal cancer cells produce abnormal cell surface glycoproteins, which facilitate detachment from the original tissue and migration to other body parts. Furthermore, the microvasculature in solid tumors, such as in esophageal cancer, is often poorly differentiated and highly-permeable enabling easier passage of cancer cells into the bloodstream. Compromised lymphatic drainage in tumor tissues can lead to accumulation of cells in new locations, potentially creating new tumor sites. The up-regulation of matrix metalloproteinases (MMPs) particularly MMP2 and MMP9, is associated with the invasion and metastasis of many human tumors, including esophageal cancer.