Lymphovascular invasion (LVI) is a finding in breast cancer pathology reports. It refers to cancer cells observed within the small blood vessels or lymphatic channels surrounding a primary tumor. Understanding LVI helps patients comprehend an important aspect of their diagnosis.
What Lymphovascular Invasion Means
Lymphovascular invasion is a microscopic finding. It occurs when cancer cells from the primary tumor are observed to have entered the tiny lymphatic vessels or blood vessels. These vessels form a network throughout the body, providing pathways for fluid and blood circulation.
The presence of cancer cells within these channels is a concern because these vessels serve as potential routes for cancer cells to travel away from the original tumor site. This process is a preliminary step in metastasis, where cancer cells can spread to other parts of the body. It indicates the tumor’s potential to spread, rather than confirming extensive spread has already occurred.
The lymphatic vessels are part of the body’s immune system, collecting fluid and waste, and eventually draining into lymph nodes. Blood vessels are part of the circulatory system that transports blood throughout the body. While both represent potential avenues for spread, lymphatic invasion is more commonly associated with spread to regional lymph nodes, whereas vascular invasion presents a more direct route to distant organs.
Identifying Lymphovascular Invasion
Lymphovascular invasion is identified by a pathologist, a medical doctor specializing in diagnosing diseases by examining tissues and fluids. This assessment occurs during the microscopic examination of breast tissue that has been removed during a biopsy or surgical procedure, such as a lumpectomy or mastectomy. The tissue samples are carefully processed, thinly sliced, and then mounted on glass slides.
To make cellular structures visible, the tissue sections are stained with special dyes, most commonly hematoxylin and eosin (H&E). Pathologists then review these stained slides under a high-powered microscope. They look for distinct clusters of cancer cells located within the identifiable spaces of small blood or lymphatic vessels.
Sometimes, specific immunohistochemical stains are used to confirm the presence of these vessels and the cancer cells within them. The pathologist’s report will state whether LVI is present or absent, informing the patient’s oncology team.
Significance for Breast Cancer Outlook
The presence of lymphovascular invasion is considered an adverse prognostic factor in breast cancer. This means it is associated with a greater likelihood of the cancer recurring or progressing. LVI indicates a more aggressive tumor and an increased risk that cancer cells may have already spread beyond the primary site.
Specifically, LVI is linked to a higher probability of regional lymph node involvement, even when initial imaging or sentinel lymph node biopsy might not detect spread. It also suggests an elevated risk of distant metastasis, where cancer cells travel through the bloodstream to establish new tumors in organs far from the breast. This is because the invaded vessels provide direct pathways for cancer cell spread.
LVI is one of several factors that pathologists and oncologists consider when assessing a patient’s overall risk profile. Other significant factors include tumor size, the histological grade of the tumor (how abnormal the cancer cells look), the status of nearby lymph nodes, and the presence of hormone receptors (estrogen receptor, progesterone receptor) and HER2 protein on the cancer cells. All these elements are integrated to provide a comprehensive understanding of the disease’s potential behavior.
How LVI Influences Treatment
The presence of lymphovascular invasion significantly influences decisions regarding a patient’s breast cancer treatment plan. Because LVI suggests a higher risk of microscopic cancer cells having escaped the primary tumor, oncologists often recommend more intensive adjuvant therapies. These treatments are given after surgery to reduce the likelihood of recurrence.
For example, a patient with LVI might be recommended for chemotherapy, even if their tumor is small and lymph nodes appear negative. Chemotherapy works systemically, aiming to destroy any circulating cancer cells or micrometastases throughout the body. Radiation therapy might also be considered more frequently, especially to the regional lymph node basins, to target any potential remaining cancer cells locally.
Additionally, LVI can influence the use of targeted therapies or hormone therapies, depending on the specific characteristics of the tumor. The goal is to tailor the intensity of treatment to the individual’s specific risk profile, aiming to eradicate any potential microscopic disease and improve long-term outcomes. LVI is not the sole determinant of treatment, but it is an important factor that helps guide a comprehensive treatment strategy alongside other prognostic indicators.