Metastasis, Local & Systemic Effects

How do cancer cells metastasize through local spread?

Local spread is helped by enzymes made by the cancer cells, and growth is via “crablike” extensions

What is a requirement for Distant spread?

Cancer cells must invade lymph and blood vessels for distant spread

How do cancer cells metastasize through distant spread?

Distant spread is helped by lymphangiogenesis and neoangiogenesis which is the growth of lymph and blood vessels into the tumor

How are carcinomas spread?

Carcinomas (epithelial tissue derived) spread through lymph

How are Sarcomas spread?

Sarcomas (fibrous tissue derived) spread through blood

If cancer cells are spread in the lymph, what node must they lodge in first?

Cancer cells spread in the lymph must lodge first in the sentinel node

If cancer cells are spread through blood, which organ is most likely to be affected? What is an example of this?

Cancer cells spread through blood often affects the organ that is next in the vascular pathway

• Ex: Liver is a common place of metastasis from tumours in the intestine

Describe the steps of Invasion and Metastasis

CIGEESR

1. Cancer cells must evolve the characteristics needed to metastasize

2. Invade the interstitial spaces of local tissue

3. Go to sentinel lymph node

4. Enter the venous system

5. Evade the innate immune system by mimicking normal cells by coating with platelets

6. Secrete proteolytic enzymes to penetrate tissues from blood vessels

7. Release cytokines and growth factors and develop the ability to perform angiogenesis

In women with malignant ovarian cancer, how many cells survive to start a secondary tumor?

Fewer than 1 in 10,000 survive to start a secondary tumor

How does compression of a tumor affect the body?

Compression of a brain tumor can lead to headaches, nausea and loss of consciousness

How can obstruction of a tumor affect the body?

Obstruction of a tumor can block airways or the gut

How can Hemorrhage of a tumor affect the body?

Hemorrhage can occur due to damage to blood vessels in the intestines and lungs

How can Infarction of a tumor affect the body?

Infarctions can obstruct blood vessels, causing local necrosis of tissues

• Exmaple: blood in stool from colorectal cancer

Where in the body can a rupture or perforation occur?

Rupture or perforation can occur in the gut or ovary

What are effusions? Where can they occur?

Effusions are inappropriate amounts of fluid.

Effusions can occur in 65% of women with ovarian cancer, in the form of ascites (excess fluid in the peritoneal cavity)

What is paraneoplastic syndrome’s symptoms triggered by?

Paraneoplastic syndrome is when symptoms are triggered by substances released by cancer cells rather than the direct local effects of the tumor itself

What are other examples of system manifestations of cancer?

Pain in later stages and fatigue that is not relieved by sleep or rest

What is Cachexia?

Cachexia is the loss of body mass due to metabolic disturbances caused by a disease

Can cachexia be reversed with adequate caloric intake?

No, cachexia cannot be reversed even with adequate caloric intake

What is anemia, leukocytopenia and thrombocytopenia?

Anemia is a low RBC count

Leukocytopenia is a low WBC count

Thrombocytopenia is a low platelet count

What causes anemia, leukocytopenia and thrombocytopenia?

They are caused by chemotherapy, radiotherapy, and malignancy in blood-forming organs

What is the most significant cause of complications and death?

Infection is the most significant cause of complications and death due to loss of immune cells

How can GI tract issues arise from cancer?

Chemotherapy and radiation therapy affects the rapidly multiplying epithelial lining, causing oral ulcers and malnutrition

How can hair and skin get damaged by therapies?

Hair and skin have rapidly growing tissues that are affected, causing alopecia, skin sensitivity and burns