cancer and its types - an introduction to cancer

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!!