Chapter 3.3 Tumor Progression

Question 1

What is key hallmark of malignant neoplasia?

Defining feature of malignant neoplasia?

Answer 1

What is key hallmark of malignant neoplasia? locally invades

Defining feature of malignant neoplasia? will spread to distant sites/metastasis

Question 2

What is the characteristic spread of carcinomas?

Answer 2

lymphatic spread is characteristic of carcinomas.

initial spread is to regional draining lymph nodes (when patient develops breast cancer, common site is spread to lymphatics then to axillary lymph nodes (which drain the breast) carcinomas spread via lymphatics to regional lymph nodes

Question 3

What type of spread is characteristic of sarcomas?

Answer 3

(sarcomas are malignancy of mesenchymal tissue)

Hematogenous spread is characteristic of sarcomas and some carcinomas

characteristic of spread into the lung

Question 4

Hematogenous spread is characteristic of sarcomas. Lymphatic spread is characteristic of carcinomas.

What are the exceptions?

Answer 4

Hematogenous spread is characteristic of sarcomas and some carcinomas

• renal cell carcinoma (invades into renal vein and can present with distant metastases)
• hepatocellular carcinoma (likes to invade hepatic vein and spread to distant sites)
• follicular carcinoma of thyroid
• Choriocarcinoma (malignancy of placental tissue, cells that line villi of placenta= trophoblasts … trophoblasts normal function is to find blood vessel and invade blood vessels; so hematogenous spread makes sense)

Question 5

What is “omental caking”?

Answer 5

“seeding” of body cavities
ex: ovarian cavities

in abdomen
cancer has replaced omentum; when cut through it has consistency of cake “omental caking”

Question 6

Accumulation of mutations results in invasion and spread. Describe the process by which a cell can manage this.

Answer 6

Normally epithelial cells sit on a basement membrane; the cells are attached to each other by various molecules; cadherins are subgroup and cadherins keep cells attached to one another; if tumor wants to spread locally and metastasize it has to dissociate from its neighbors; it can downregulate E-cadherin to do so

once E cadherin is downregulated, this cell will attach to the laminin present in BM (BM is composed of collagen IV and laminin) so cell, once dissociated from neighboring cells will attach to laminin in BM, then they will destroy the BM with collagenase they produce

now the cell is outside in the extracellular matrix. it will attach to Fibronectin; now it can spread locally

may gain access to blood vessels (spread to distant sites) or lymphatics (spread to lymph node)