cancer and its types - an introduction to cancer
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An introductory lecture to cancer, concepts and fundamentals... for medical and paramedical studentsTRANSCRIPT
Cancer and its TypesCancer and its Types
Dr. Dr. AshishAshish JawarkarJawarkar M.D.M.D.PathologistPathologist
ParulParul SevashramSevashram HospitalHospital
OVERVIEWOVERVIEW• How common is cancer• Understand cancer• History• How cancer starts• How cancer spreads• Stop cancer
How common is cancerHow common is cancer• According to national cancer control
programme – there are nearly 2.5 million cancer patients in India
• About 0.7 million new cases are diagnosed each year, and nearly half of them die
• More than 60% of these patients are in the age of 35-60, prime of their life
• It is expected that with improved life expectency – the number of cases will triple in the coming years
• About 1 in 4 of us will get cancer• About 1 in 5 of will die due to
cancer
Normal cell division Normal cell division • There are trillions of cells in our body• Healthy cells are programmed to
“know what to do and when to do it”.
What is CancerWhat is Cancer• Cancer is a general name for more
than 100 different diseases• The common point about all these
different diseases is that a particular cell of the body is growing out of control
• Cancer cells donot know “what to do, and when to do”
• This division uses up all the resources required by other cells of the body
Some commonly used termsSome commonly used terms• Neo-plasm – new growth• Tumor – swelling caused by
neoplasm• Benign neoplasm – one which is
restricted by its capsule – doesnotspread to other areas of body
• Malignant – one which spreads to different parts of the body
HistoryHistory• The oldest description of cancer
dates back to 1600 BC in Egypt
• Papyrus described 8 cases of ulcers of breast treated by cauterization by a tool he called – the fire drill
• He had said – the disease has no cure
HistoryHistory• Hippocrates – 460-370 BC• Described several types of cancers –
called them carcinos (crab)• Cut surface of tumors with veins in all
directions
The father of Western Medicine
CELCUS AND GALENCELCUS AND GALEN• Celcus (25 BC) translated carcinos
into latin – cancer• Galen suggested the word oncos for
swelling – Oncology thus was named
Cause of cancer -Humoral theory
• Though Hippocrates, Celcus and Galen described cancer, they did not know the cause
• Cause of cancer was said to be imbalance of body fluids
• black/yellow bile,blood and phlegm• Cancer was said to be caused by excess of
black bile• Accordingly treatment was change of
diet/blood letting /laxatives
MorgagniMorgagni• In 1761, Morgagni first performed
autopsies• He studied postmortem findings and
suggested causes of diseases• This lead the foundation of
scientific study of cancer -oncology
On the sites and causes of diseases
Era of cancer surgeryEra of cancer surgery• The famous Scottish surgeon John
Hunter (1728−1793) suggested that some cancers might be cured by surgery.
• If the tumor had not invaded nearby tissue and was “moveable,” he said, “There is no impropriety in removing it.”
• He conducted a lot of autopsies and studied cancer
Body snatching
Upcoming TV show – knife man
Primitive surgery• No asepsis / anaesthetic techniques
were available• Mortality was more due to
secondary infections that cancer per se
RECURREDRECURRED• It took nearly a century for the
development of anesthesia and asepsis
• This allowed surgery to flourish and classic cancer operations such as the radical mastectomy could be done effectively
• Any and every cancer was removed – this prolonged life somewhat – but cancer recurred
• Till this time – no one had actually seen cancer cells!!!
Birth of microscopic Birth of microscopic pathologypathology
• The 19th century modern microscope was invented and cancerous tissue could be studied.
• Rudolf Virchow, often called thefounder of cellular pathology, linked microscopic findings with cancer types.
First actual cause of cancer First actual cause of cancer discoverydiscovery
• In 1713, Bernardino Ramazzini, an Italian doctor, reported the virtual absence of cervical cancer and relatively high incidence of breast cancer in nuns
• This was linked to their celibate life style• This observation was an important step
toward identifying and understanding the importance of hormones and cancer risk
Scrotal cancerScrotal cancer• In 1775, Percival Pott of Saint
Bartholomew’s Hospital in London described an occupational cancer in chimney sweeps, cancer of the scrotum
• was caused by soot collecting in the skin folds of the scrotum.
TobaccoTobacco• Thomas Venner of London was
one of the first to warn about tobacco dangers in his Via Recta, published in London in 1620.
• He wrote that “immoderate use of tobacco hurts the brain and the eye and induces trembling of the limbs and the heart.”
• And 150 years later, in 1761, only a few decades after recreational tobacco became popular in London, John Hill wrote a book entitled -Cautions Against the Immoderate Use of Snuff.
• Inspite of this, tobacco use continued unabeted
• Lead to an epidemic of sorts, of tobacco related cancers
• These first observations linking tobacco and cancer led to epidemiologic research many years later (in the 1950s and early 1960s) which showed that smoking causes lung cancer and led to the US Surgeon General’s 1964 reportSmoking and Health.
• This report lead to some regulations on tobacco companies
• They had to affix warnings on their products
Powerful tobacco lobby
• Still they avoided the word - CANCER
Genetic causeGenetic cause• The genetic basis of cancer was
proposed by German zoologist Boveri in 1902
• He suggested the mutations of chromosomes lead to cancer
RadiotherapyRadiotherapy• Marie curie discovered radium, and
radiation at the end of 19th century• This marked the discovery of first
non surgical mode of cancer treatment
Brachytherapy
Complete cancer cureComplete cancer cure• During World war II, the nuclear
bombings of Hiroshima and Nagasaki took place
• It was observed that the radiation of the bombings destroyed the marrow of the victims
• This in turn gave a hope of curing cancer completely by radiation
How cancer startsHow cancer starts
• Cancer starts with damage to the DNA
Causes of DNA damageCauses of DNA damage
TobaccoTobacco
Fast food (Fast food (fibrefibre free)free)
Hormonal causesHormonal causes
Due to viruses (HPV)Due to viruses (HPV)
UV rays UV rays –– sun tanningsun tanning
Signs and symptoms of Signs and symptoms of cancercancer
• Depends on the location
– Change in bowel or bladder habits– A sore that does not heal– Unusual bleeding or discharge– Thickening or lump in breast or elsewhere– Indigestion or difficulty in swelling– Obvious change in wart or mole– Nagging cough or hoarseness
Spread of cancerSpread of cancer• Local spread• Lymphatic spread• Metastasis
Local spreadLocal spread
Lymphatic spreadLymphatic spread
Lymphatic spreadLymphatic spread
Lymphatic spreadLymphatic spread
Spread via bloodSpread via blood
Can we treat cancer??Can we treat cancer??• Cancer cells are our cells –• killing them = killing ourselves• Main treatments available
–Surgery – Recurs–Chemotherapy – damages normal cells–Radiotherapy – damages nearby areas
Newer treatmentsNewer treatments• Imatinib – revolutionized treatment
of CML• Herceptin – for treatment of breast
cancer• Rituximab – against NHL
StillStill…… Prevention is curePrevention is cure• Limiting tobacco exposure• Limiting alcohol intake• Modifying diet• Limiting exposure to UV rays• Screening programs
What is screening??What is screening??• looking for cancer before a person
has any symptoms• When abnormal tissue is found early
stage, it may be possible to treat it completely
• Following cancers are amenable to screening– Breast– Prostate– Cervix– Colon and rectum– Lung
Breast cancer screeningBreast cancer screening
Breast cancer screeningBreast cancer screening• Has lead to a 15-20% reduction in
deaths due to breast cancer• American cancer society
recommends breast cancer screening for all women more than age 40 , every year
• Includes–Mammography–Clinical breast examination–Breast self examination
MammographyMammography
Clinical breast examinationClinical breast examination
Breast self examinationBreast self examination
Cervical cancer screeningCervical cancer screening
Pap testPap test
Prostate Cancer screeningProstate Cancer screening• Screening can be started for
–Moderate risk males – age 50–High risk males – age 45–Very high risk males – age 40
• Screening consists of –Digital rectal examination–PSA examination
Colon cancerColon cancer
Colon cancer screeningColon cancer screening
Lung cancer screeningLung cancer screening• Guidelines recommending annual
low-dose CT lung cancer screening have been approved by the US Preventive Services Task Force.
• The recommendations apply to individuals aged between 55 and 80 who are at high risk for lung cancer as a result of heavy smoking.
Take home messageTake home message• Cancer is a group of diseases affecting
human kind since ages• It is controllable – not yet completely
curable at early stages• Screening programs help in reducing
morbidity and mortality from cancer• Gearing cancer research towards knowing
the molecular mechanisms of cancer can help in developing treatment modules
ReferencesReferences• The Emperor of all maladies - by
Siddhartha Mukherjee• Robbins pathology• A lot of wikipedia• Google baba ki Jai Ho!!