Cancer chemotherapy

Chemotherapy can potentially cure…

• acute leukemias (particularly in children—90+%; 50-60% in adults)

• lymphomas

• small cell carcinoma of the lung, which behaves like a lymphoma

• testicular cancer, even with significant metastases (e.g. to the brain)

• childhood solid tumors

  • osteosarcoma

  • neuroblastoma

  • Ewing’s sarcoma

• these are the fast-growing tumors

Adjuvant chemotherapy (i.e., chemo after surgery) can prevent relapses in…

• breast cancer, in > ½ of people

• colorectal cancer

• lung cancer—adjuvant chemo helping lung cancer relapse is relatively new information (2 years)

• maybe prostate and bladder cancer

Neo-adjuvant chemo-radiotherapy can downstage to allow resection of locally advanced tumors

• first, chemotherapy sensitizes the tumor to radiotherapy and then radiotherapy works locally to shrink the tumor

• breast cancer

• lung cancer (“Pancoast tumor”)

• rectal cancer

• esophageal cancer

• head & neck cancer

• bladder cancer

Palliative chemotherapy for metastatic solid tumors

• most of the metastatic solid tumors (with the exception of those mentioned earlier) have growth so large that they are usually not curable

• these include metastatic lung, breast, colorectal, prostate ca

• goals

  • prolong life (breast cancer metastasis—pt might live for a decade) or delay symptoms

  • palliate existing symptoms and improve quality of life

    • reduce pain, obstruction

    • reduce B-symptoms, i.e. consequences of cytokine release from tumors

      • fevers

      • night sweats

      • weight loss

  • minimize side effects (do no harm)

Chemotherapy for non-malignant diseases

• immunosuppression post organ transplant

• rheumatologic disease: rheumatoid arthritis, systemic lupus erythematosus (methotrexate)

• multiple sclerosis

• psoriasis (methotrexate)

• autoimmune hemolysis and idiopathic thrombocytopenic purpura (Rituximab)

• sickle cell anemia

Problems with chemotherapy

• low therapeutic indices

• limited activity in non-cycling cells; limited effect on cancer stem cells

• rapid emergence of resistant clones

• there is no single unique cancer phenotype, except in chronic myelogenous leukemia (BCR-ABL)

• targeted therapy typically has low response rates unless used in combination

Category: Pharmacology Notes