Routes Of Spread

Question 1

Routes of spread

Answer 1

Refers to how cancer spreads through the body through several routes

Question 2

Direct spread/ local invasion

Answer 2

For non-melanoma (bcc )→ exophysic lesions and are slow graving, rarely metastasise and cause cause death but can erode local anatomical structures

Question 3

Lymphatic spread

Answer 3

Cancers from endothelial and epithelial walls follow this route
Small groups of tumour cells infiltrate and penetrate the thin wall of lymphatics.
•This is often the primary route of spread and metastatic disease – why?
•Regional lymph nodes- Breast Ca, melanoma, prostate cancer

Question 4

Lymphatic spread (2)

Answer 4

cSCC usually spreads to local lymph nodes and clinically enlarged nodes should be examined histologically (by fine needle aspiration (FNA) or excisional biopsy).

Question 5

Haematogenous spread

Answer 5

Sarcomas and some types of carcinomas tend to follow this route.

Lymphatic spread may eventually, in later stages of cancer, lead to systemic haematogenous spread. This is because the thoracic and right lymphatic duct connect the lymph to blood.

For example, breast cancer can spread through the lymphatic system, but is also found to commonly spread to the bone marrow through blood circulation.

Question 6

Blood spread

Answer 6

Invasion
–blood vessel within the tumour - angiogenesis
–cross the lining of the endothelial cells that form the blood vessel.

•Adhere to the wall of vessel or organ.
•Lung, liver, brain and bone are the most common destination organs.

Question 7

Transcoelomic spread

Answer 7

Cancer cells spread through surfaces of body cavities. Cancers commonly following this route of metastasis originate in organs surrounded by body cavities that are lined. Ovarian tumours are an example, as the peritoneal cavity surrounds the ovary

Question 8

What are Ascites ?

Answer 8

Fluid that accumulates within the peritoneal cavity

Question 9

What are malignant ascites?

Answer 9

Malignant ascites indicates the presence of malignant cells in the peritoneal cavity

Question 10

Perineural and leptomeningeal ( CNS)

Answer 10

Spinal cord tumours spread along and around the spine and spinal cord. They may also shed cancer cells into the CSF.

Question 11

Perineural spread

Answer 11

the spread of cancers into the sheaths (or layers) of nerves. This is not common, but found most commonly in the head and neck, prostate, and colorectal, where these sites are heavily innervated.

Question 12

Leptomeningeal spread

Answer 12

the spread of cancers by the cerebral spinal fluid. Many of the cancers that follow this route begin in the brain, but not all. These include non-Hodgkin’s lymphoma, where the risk of leptomeningeal spread increases in patients with AIDS.

Question 13

Transplantation spread

Answer 13

Is not biological in occurrence

the mechanical spread of cancers that occur from fragmentation of tumours caused by surgical equipment in operation or needles from biopsy.

Question 14

Why do cancers spreed where they do?

Answer 14

Breast cancer cells that leave primary site via blood vessels carried in blood flow, first through heart, then to capillary beds of the lungs.

•Some ca cells may pass through lungs to enter systemic arterial system, where transported to remote organs eg. bone.

•Others might form metastases in the lungs and then shed cells into the arterial flow.

•By contrast, colon cancer cells taken by hepatic –portal circulatory system first to the liver.

•There is no direct flow from the lymphatic system to other organs, so cancer cells with in it must enter the venous system to be transported to remote organs.