Pharmacology - Cancer Flashcards
What is cancer?
Epigenetic disease resulting in the reprogramming of cancer cells so that they are growing in a no regulated manner and overcome physiological tissue and organ barriers (Invasive growth)
What are the main 2 causes of cancer?
1) Germline mutations/hereditary familil syndromes (5-10%)
2) Environmental factors/somatic mutations (90-95%)
What are the main risk factors of cancer?
1) Diet (35%) - (obesity (20%))
2) Smoking - 30%
3) Chronic infections (15-20%)
- Viruses 70%
What cancers have the highest and lowest 5 year relative survival for men and women?
Men: Highest > Testes 96% > Hodgkin lymphoma 84% Lowest > Pancreas 3% > Lung 6%
Women Highest > Melanoma 90% > Hodgkin lymphoma 83% Lowest > Pancreas 2% > Lung 6%`
What is the major cancer treatment?
Surgical removal of the tumour if detected early enough
What is radical mastectomy and when was it first indroduced?
surgical procedure in which the breast, underlying chest muscle (including pectoralis major and pectoralis minor), and lymph nodes of the axilla (armpit area) are removed as a treatment for breast cancer.
1894 to avoid cancer spread
For how long did radical mastectomy remain a standard procedure?
> 70 years
What therapy was introduced to replace radical mastectomy?
Removal of tumour mass plus chemo/radiotherapy
Equally effective but less morbidity
How does untreatable cancer kill patients?
Primary tumour and/or metastases destroy essential tissue and organs
- wasting syndrome (20%): appetite loss, weight loss, weakness, fatigue, muscle atrophy
- Only 1 in 5 patients with metastasised disease will survive >5 years
What percentage of cancer cures are achieved by which therapy?
- Systemic therapy (most common is chemotherapy) - 11%
- Local radiotherapy - 40%
- Surgery - 49%
What limits the efficacy of anti-cancer therapies?
1) Drug concordance (patients need to take their drugs)
2) The therapeutic window is very small
3) Do not fully understand the action of anti cancer drugs
4) Complicated disease
5) Cancer cell populations are highly adaptable
Why is the cancer therapeutic window so small?
Because cancer cells and normal diploid non maligant cells are so similar
- differences are in expression levels of genes but limited number of cancer specific mutations
- Result is that anti cancer drugs also have some non specific activity on normal cells
Describe some factors that contribute to cancer complexity?
Every cancer is its own unique disease:
- Genetic factors differ
- Time point of cancer formation
- Time point of diagnosis
- The therapy
Metastases may require different treatment than the primary tumour
AND
Different cells from the same tumour may require different treatment
How are cancer cells so highly adaptable?
They undergo clonal evolution by natural selection
Selection pressures include:
- hypoxia (oxygen deficiency)
- starvation
- Anti-cancer therapy
- different microenvironments (invasion of other tissues)
What is the result of cancer cell adaptability?
Initially respond to treatment but eventually mutant resistant cells emerge and proliferate