Cancer Lecture 1

  • Introduction

    • Otto Sanchez, professor at the Faculty of Health Sciences, and associate dean

    • Specializes in cancer research, discussing cancer in the context of prevention

  • Overview of Presentation Themes

    • Cancer trends in Canada as a chronic disease

    • Natural history of cancer

    • Cancer biology concepts relevant to prevention

    • Case studies in cancer prevention

  • Cancer Trends in Canada

    • Cancer is a leading cause of death, accounting for 28%-30% of deaths in recent years

    • Transition from cardiovascular disease to cancer as the top cause of death over past decades

    • Cardiovascular death rates decrease due to better fitness and diet

    • Cancer's prominence highlights the need for focus on prevention

  • Canadian Cancer Statistics (2015)

    • Approx. 200,000 Canadians diagnosed with cancer in 2015

    • This translates to about 540 new cases every day

    • Estimated 80,000 cancer-related deaths in 2015 (approximately 214 per day)

    • Most diagnosed individuals survive; death rates lower than incidence rates

  • Cancer Survival Rates by Type

    • Cancer types vary in survival rates; some are acute while others are chronic

    • Slow progression cancers (e.g., pancreatic, lung) have lower survival rates

    • Chronic cancers (e.g., thyroid, testicular) have higher survival rates

  • Trends in Cancer Mortality

    • Overall decline in cancer mortality observed in recent decades

    • Improvements in diagnosis and treatment lead to higher survival rates in men (lung, colorectal, prostate cancers)

    • Women show similar trends, except lung cancer remains a concern due to historical smoking patterns

  • Historical Context of Cancer Treatment

    • Significant advancements in treatment occurred after 1948, introducing chemotherapy and radiotherapy

    • Introduction of leukemia treatments dramatically improved survival rates, particularly in children

  • Natural History of Cancer

    • Cancer progresses over years, with long latency periods between exposure and diagnosis

    • Importance of understanding cancer's evolution from initial mutation to metastatic disease

    • Dormancy concept: cancer cells can remain dormant after treatment, posing a risk of recurrence

  • Carcinogenesis Model

    • Initiation, promotion, and progression define the cancer development process

    • Two-hit hypothesis: carcinogen exposure followed by promoting factors is necessary for cancer growth

    • Example: Aflatoxins as carcinogens needing additional promoting agents like hepatitis B for liver cancer

  • Carcinogen Definitions and Classifications

    • Carcinogens are substances that induce cancer, often acting through DNA damage

    • Classified by the International Agency for Research on Cancer (IARC), with Group 1 being carcinogenic to humans

    • Examples: Tobacco, asbestos, pollution, some chemicals, and biological agents like viruses

  • Environmental Factors

    • Questions about controllable vs. uncontrollable environmental carcinogens

    • Well-established carcinogens include solely tobacco and UV radiation

    • Ongoing debates on less certain agents (e.g., cell phone radiation, air pollution)

  • Cancer Prevention Strategies

    • Four levels of cancer prevention: primordial, primary, secondary, and tertiary

    • Primordial: Addressing socio-environmental factors that affect health

    • Primary: Reducing exposure to carcinogens (e.g., tobacco control)

    • Secondary: Early-stage cancer detection to prevent progression

    • Tertiary: Minimizing suffering and complications for diagnosed individuals

  • Existential Questions Regarding Cancer

    • Questions faced by cancer patients around causation, lifestyle, early detection, and mortality

    • Highlights the personal impact of cancer on individuals and families

  • Conclusion

    • Importance of education on cancer trends and prevention for future healthcare professionals

    • Presentation encourages active participation in cancer awareness and prevention efforts

  • Next Steps

    • Follow-up discussions in class will delve deeper into case studies and specific cancer prevention methods.