Outline
Clinical epidemiology of Cancer - How Big is the Problem?
Neoplasia – What is it?Risk Factors and ScreeningDiagnosis and StagingTreatmentsQuiz
Cancer Epidemiology Canadian Cancer Stats
More men than women are diagnosed with cancer 51.7% vs 48.3%
Over ¼ (27%) of all cancer death due to lung cancer
Between 1995-2005, overall cancer mortality has declined
Increasing incidence of cancer is mainly due to aging population
Quiz
Which cancer has the highest incidence? In men?
Prostate CancerIn women?
Breast cancer
Which cancer has the highest mortality rate?In men?
Lung cancerIn women?
Lung cancer
Prostate27%
Lung14% Colorectal
13%
Bladder6%
Non-Hodgkin lymphoma5%
Kidney3%
Leukemia3%
Melanoma3%
Oral3%
Pancreas2%
All other cancers21%
10 most common cancers in men (percentage of all new cancers in men), Canada, 2011
Data source: Canadian Cancer Statistics 2011
Prostate10%
Lung28%
Colorectal13%
Bladder3%Non-Hodgkin lymphoma
4%Kidney
3%
Leukemia4%
Pancreas5%
Stomach3%
Esophagus4%
All other cancers23%
10 most common causes of cancer death in men (percentage of all cancer deaths in men), Canada, 2011
Data source: Canadian Cancer Statistics 2011
Breast28%
Lung14%
Colorectal11%
Body of Uterus6%
Thyroid5%
Non-Hodgkin lymphoma4%
Ovary3%
Melanoma3%
Pancreas3%
Leukemia3%
All other cancers20%
10 most common cancers in women (percentage of all new cancers in women), Canada, 2011
Data source: Canadian Cancer Statistics 2011
Breast15%
Lung27%
Colorectal12%
Non-Hodgkin lymphoma4%
Ovary5%
Pancreas6%
Leukemia3%
Body of Uterus2%
Brain2%
Stomach2%
All other cancers22%
10 most common causes of cancer deathin women (percentage of all cancer deaths in women), Canada, 2011
Data source: Canadian Cancer Statistics 2011
Cells and MoleculesNeoplasm:
Characterized by growth and division of cells outside the control of normal regulatory mechanisms
Cells have undergone permanent DNA damageCharacterized as benign or malignant by their
capacity for invasion and metastasisMalignant tumours are divided most broadly
into carcinomas and sarcomas, and blastomas in children
Exceptions to the rule: Hepatoma, Melanoma, Leukemia,lymphoma, Glioblastoma
This figure was adapted from Cell, Vol 100, Hanahan and Weinberg, The Hallmarks of Cancer, pp 57-70, Copyright Elsevier (2000).
Genetic ChangesCancers arise due to changes in a cell’s genetic
machineryOncogenesTumour suppressor genes
Oncogenes eg. bcr-abl in CMLGenes have dominant transforming properties: one
abnormal copy is sufficient Mutation or overexpression leads to unregulated
cell divisionTumour Suppressor Genes eg. BRCA1/2, RB
Genes which are normally involved in the negative regulation of cell cycling
Genes have recessive transforming properties: both copies must be abnormal
loss of these genes function allows cells to proliferate unregulated, or with reduced restraints
CRC Adenoma-Carcinoma Sequence:CRC Adenoma-Carcinoma Sequence:Vogelstein’s modelVogelstein’s model
Mutations can be inherited, or occur through exposures to carcinogens
CarcinomasCarcinomas
Arise from epitheliumCommonest are adenocarcinoma and squamous
carcinomaMany others, including germ cell tumours,
transitional cell carcinomas, large cell carcinoma, neuroendocrine carcinoma
Adenocarcinoma BreastLungProstateMost GI, including colonEndocrine malignancies
CarcinomasSquamous carcinoma
Head and neck cancersLungSkinCervixEsophagusanus
Germ Cell TumoursMost commonly testicular cancersOvarian Primary mediastinalHistologic subtypes include teratomas,
embryonal carcinomas, yolk sac tumours
SarcomasMuch rarer than carcinomasArise from mesenchymal tissueAbout 800 soft-tissue sarcomas per year in Canada, and
fewer bone sarcomasNamed for the tissue they arise from, when knownKnown tissues of origin
Liposarcoma FatRhabdomyosarcoma Striated muscleLeiomyosarcoma Smooth muscleOsteosarcoma BoneChondrosarcoma Cartilage
Unknown tissue of originMalignant fibrous histiocytoma, Ewing’s Sarcoma, alveolar soft
parts tumour
SummaryHistologic characteristics of cancer
Excessive cellularityDisrupted architectureFrequent mitosesUnusual cell appearance
Large, hyperchromatic nucleiVarying degrees of differentiationInvasion into surrounding tissue
ScreeningScreening is the routine testing of
asymptomatic individuals for the presence of cancer
Good screening strategy:Test is acceptable to the target populationRisk is minimal and cost is reasonableTest is accurate: high sensitivity and specificityTest detects the disease in an asymptomatic
(pre-clinical) phaseEvidence exists that treatment in the
asymptomatic phase improves outcomes
ScreeningCommonly screened cancers in adults are:
Breast (mammography)Cervix (Pap smears)Colon (FOBT/colonoscopy/sigmoidoscopy)Prostate (PSA)
Evidence behind screening is surprisingly controversial, in part because of the difficulty of designing studies to avoid bias
ScreeningLead-time Bias
Time
Cancer starts
Symptoms
Diagnosis and treatment Death
Diagnosis by screening
Treatment
Cancer becomes incurable
Why Not Screen for All Cancers?
Cancer-related factors
Preclinical interval too short
Cancer incurable, even if screen detected
Cancer Starts Symptoms Death
Cancer Starts Symptoms DeathIncurable
Incurable
Why Not Screen for All Cancers?Test-related factors
Test not sensitive/specific enoughTest can’t be applied to whole population
Too expensiveInsufficient infrastructure/personnelUnacceptable to majority of population
Tumour not common enough
Risk factorsCausal inference:
•Temporality- exposure to precede disease
•Strength of association – stronger association between an exposure and cancer risk is more likely to be causal than a weaker association
•Consistency - association between exposure and outcome demonstrated from other studies
•Gradient of effect – increasing levels of exposure are accompanied by increasing in risk
•Biological plausibility – if the causal model agrees with present knowledge about biology of the target cells and tissues and the biological effects of the exposure
•Specificity – if an association is present between a single exposure and a single disease
Risk Factors for cancer
Factor Type Attributable Risk
Environmental 5%
Lifestyle 45%
Occupational 4%
Pharmacologic 2%
Biologic 4%
Risk Factors for lung cancer90% of all lung cancers are attributable to
smoking Including 2nd hand smoking
10% occur in non-smokers (younger, female, Asian)
Risk increases with # packs smoked, age at onset
Tobacco smoke has > 40 identified different carcinogens
Women are more susceptible to carcinogenic effects
Other risks include some occupational exposuresAsbestos, radon, sillica, chromium, arsenic
Risk factors for breast cancer
Hormonal and reproductive riskEarly
menarcheFirst birth at
older ageAbsence of
breast feedingNulliparityLate
menopauseHRT
Age and gender – older and female
Race/ethnicity – whites>blacks>hispanic/indians/asians
Diet/LifestylePost-menopausal obesityAlcohol
Medical historyIonizing radiationIncreased breast densityBenign breast lesions
Environmental
Risk factors for breast cancer
Family history and genetic risksBreast cancer susceptibility gene 5-6% of all
BCBRCA1/2, p53, ATM, PTEN
BRCA mutationsBRCA1
75 % lifetime risk of breast cancer50 % lifetime risk of ovarian cancer
BRCA275 % lifetime risk of breast cancer25 % lifetime risk of ovarian cancerMelanoma, laryngeal, colon, prostate, pancreas,
lymphoma, leukemia
Colorectal Cancer : Risk Factors
Dietary – most important!High fat, low fibre, high EtOH, low selenium, low calcium
Underlying ConditionsIBD, prior CRC or polyps, post-radiation
Hereditary – 5%FAP (familial adenomatous polyposis) – 1/200, APC gene
Gardener’s-intestinal polyps and osteomasTurcot’s – familial polyposis and brain tumors
HNPCC (hereditary non-polyposis colorectal ca) 2-4%Genetics: “microsatellite instability = MSI”, MSH2, MLH1,..
Peutz-Jeghers- polyps and pigmented lesions on oral mucosa/lipFamily Hx – 10% have
Risk factor for colon cancer
Family History General population 6% lifetime risk
One 1st degree relative: 12%
Two 1st degree relatives: 18%
1st degree relative <45 yrs old: 30-42%
DiagnosisEarly detection of cancer is the key Recommend screening test if availableSystematically think about symptoms of
cancerLocal symptoms of tumourSymptoms from regional (nodal) spreadSymptoms from metastatic spreadSymptoms from paraneoplastic phenomena
DiagnosisLocal Symptoms
Lung Cough, hemoptysis, SOB, chest wall pain
ProstateUrinary obstruction, hematuria
BreastBreast mass, skin changes, bleeding from nipple
Colon Blood in stool, iron deficient anemia, change in
bowel habitsHematological
Symptoms of marrow replacement, cytopenias
DiagnosisSymptoms from
regional (nodal) spreadLung (mediastinal
nodes)SVCO, esophageal
obstruction, hoarse voice, etc
Breast (axillary nodes)Lump under arm
Symptoms from Metastatic SpreadLiver
Jaundice, abnormal LFT, pain
BrainFocal neurologic
symptoms, seizuresLung
Cough, SOB, hemoptysisBone
Pain, pathologic fracture, elevated Alk Phos
DiagnosisParaneoplastic Syndromes
Common, non-specificPoor appetite, weight loss, DVT
Hormonal syndromesSIADH, Cushing’s, hypercalcemia, carcinoid
Neurologic syndromesLambert-Eaton Syndrome, demyelination syndromes
Diagnosis and StagingDefinitive diagnosis – tissue neededPurposes of staging
Group similar patients togetherDetermine intent of treatmentPrognostic purposes
Most cancers are staged with a TNM staging system, which leads to overall stage I-IVTumourNodalMetastases
TreatmentIntent of Treatment
Radical vs. PalliativePrimaryAdjuvantNeoadjuvant
Modalities of TreatmentSurgeryRadiotherapySystemic therapy
Treatment: SurgeryIndications for Surgery
Obtain tissue for diagnosis/stagingDefinitive treatment of primary tumourPalliation of obstructive/mass effect symptomsCancer prophylaxis in high-risk cases
Esophageal dysplasia/BRCA/FAP/ulcerative colitisSupport other procedures
Central venous accessRehabilitation/reconstruction
Treatment: RadiationIonizing radiation delivered to tumour
and surrounding tissueExternal BeamBrachytherapy Systemically administered agents
Radiation treatment intentCurative as primary treatment Adjuvant for local regional disease controlPalliative symptom management
Treatment: Systemic TherapyChemotherapyHormonal TherapyImmunotherapyTargeted therapy :Small
molecules/monoclonal antibodies
Treatment: ChemotherapyMechanisms of action
Bind to DNAAlkylating agents, platinum agents
Antimetabolites5-FU, methotrexate
Bind to microtubulesVinka alkylaoids, taxanes
Interfere with topoisomeraseAnthracyclines
Treatment: ChemotherapyAcute toxicities
Mucositis/diarrheaNauseaHair lossHypersensitivity
reactionsPainThromoboembolic
eventsMyelosuppression
Risk of febrile neutropenia
Fatigue
Chronic ToxicitiesInfertility
Particularly alkylating agents
LeukemogenesisAnthracyclines,
alkylating agentsNeurotoxicity
Cisplatin, taxanes, vinca alkyloids
NephrotoxicityCisplatin
Cardiotoxicityanthracyclines
Treatment: Hormonal TherapyHormone sensitive cancers
BreastProstateEndometrialOvarian
Tumours retain some characteristics of the original tissue
Treatment: Monoclonal Antibodies
Antibody Target Tumour
Trastuzumab (Herceptin) HER-2 BreastRituximab (Rituxan) CD-20 LymphomaCetuximab (Erbitux) EGFR ColonBevacizumab (Avastin) VEGF Colon, LungTositumomab (Bexxar) CD-20 + I131 LymphomaIbritumomab (Zevalin) CD20 + Y Lymphoma
Treatment: Small MoleculesMolecules developed to inhibit specific
proteins/enzymes responsible for malignant behaviorImatinib (Glieevec) CML, GISTGefitinib (Iressa) Lung cancerErlotinib (Tarceva) Lung cancerLapatinib (Tykerb) Breast cancer
Treatment – OtherPalliative care
Pain and symptom managementEnd of life care
Cancer SurvivorshipA rapidly expanding field, arising from the
recognition that people who have completed curative cancer therapy have ongoing complex medical, social, psychologic issues
Lung Cancer: NSCLCStage I-II disease
Limited to lung and ipsilateral hilar nodesSurgery gives ~50% long-term survival rateImproved to ~60-65% with adjuvant chemotherapy
Stage III DiseaseLung and ipsilateral or contralateral mediastinal lymph
nodesSeldom amenable to surgeryRadiation alone can cure 7-12%Adding chemotherapy increases rate to ~18-25%
Stage IV - Metastatic diseaseIncurable, with median untreated survivals of 4 monthsWith chemotherapy, median survival increases to 10 months50% of patients have improved symptoms or QoL on chemo
Lung Cancer: Small CellStaged as either Limited or Extensive
LimitedConfined to one hemithoraxTreated with chemo and radiation, with a long-term
survival rate of ~25%Median survival untreated: 4 months treated: 12
monthsExtensive
Beyond one hemithoraxTreated palliatively with chemotherapyMedian untreated survival 6 weeksMedian treated survival 9 months
Breast Cancer - pathologyInvasive ductal carcinoma - 76%Invasive lobular carcinoma – 8% Ductal/lobular – 7%Mucinous(colloid) – 2.4% Tubular carcinoma -1.5%Medullar carcinoma – 1.2%Papillary carcinoma -1.0% Other (micropapillar and metaplastic) – <5%
Breast Cancer Staging and Prognostic Markers
TNM stagingT - tumor extentN- nodal statusM- metatstatic disease
ER/PR receptor statusHistological grade, lymphvascular invasionHer2 status (epidermal growth factor
receptor)Gene profiling
Breast cancer treatmentStage I-II
Primary therapy – surgery for the breast lesion + regional LN
Systemic therapy – chemotherapy/hormone/targeted therapy
Radiation therapy to breast/chestwall/LNStage III
Neoadjuvant systemic therapySurgery Radiation therapy
Stage IV – metastatic Systemic therapySurgery/radiation as symptom management tools
EstrogenbiosynthesisEstrogenbiosynthesis
Tumour cell
Tumour cell
Nucleus
Adjuvant Endocrine TherapyInhibition of Estrogen-dependent Growth
EstrogenbiosynthesisEstrogenbiosynthesis
TamoxifenTamoxifenTamoxifenTamoxifen
AromataseAromataseInhibitorsInhibitors
AromataseAromataseInhibitorsInhibitors
Inhibition of growthInhibition of growth
Bhatnagar AS, et al. J Steroid Biochem Mol Biol. 2001;77:199-202.
Estrogen
Estrogen Receptor
Polychemotherapy significantly reduces the risk of recurrence and death
Absolute benefit is bigger in patients Under age 50With ER- tumorsWith Node(+) disease
Polychemotherapy regimens longer than 6 months do not appear to improve survival
1Early Breast Cancer Trialists’ Collaborative Group. The Lancet 352:930-942
Benefits of Chemotherapy
Metastatic diseasebone > lung > liver > brainMost commonly detected in first 5 years after
definitive treatmentTreatments try to improve survival and quality
of life Median overall survival from time of
diagnosis: 18-24 months5y survival: 5-10%10y survival: 2-5%Age, disease free interval, # and location of
mets, ER status, her2 status
Colon CancerStage I-III
Typically treated by surgery, with long-term control rates of 40-85%, depending on stage
Adjuvant chemotherapy decreases relative risk of recurrence by 30%, usually offered to pt with stage III or high risk stage II
Adjuvant chemo and radiation often used together in rectal, rather than colon cancers
Stage IVPalliated by chemotherapy, radiation as indicatedUntreated survival ~4-6 monthsOptimally treated survival ~24 months
Prostate CancerEarly stages maybe treated with surgery or
radiationMore advanced disease is treated with
some combination of radiation and hormone therapy (androgen deprivation)
Chemotherapy has a limited role, usually just for metastatic disease after hormones fail
Q: A unilateral vocal cord paralysis is common in the setting of a mediastinal mass and lung cancer, which vocal cord is more commonly involved?
Left vocal cord is more commonly - compression of the left recurrent laryngeal nerve
Q: Neutropenic fever is found in 30-40% of patients what is the most common etiology?
Gram positive bacteria
Q: What syndrome causes diarrhea, flushing, bronchospasm and right sided heart failure?
Carcinoid syndrome
Q: What is the term used for tumor at the apex of the lung or superior sulcus which may involve brachial plexus, sympathetic ganglion, vertebral bodies, leading to pain, upper extremity weakness and horner’s syndrome?
Pancoast tumor
Q:What is the most common paraneoplastic syndrome associated with renal cell carcinoma?
hypercalcemia (20%)
Q: What is the most common pulmonary malignancy associated with hypercalcemia
squamous cell carcinoma of the lung
Q: Multiple endocrine neoplasia
MENI - pancreatic tumors, pituitary adenoma, parathyroid hyperplasia
MEN II – parathyroid hyperplasia, medullary thyroid carcinoma, pheochromocytoma, multiple mucosal neuromata
Q: Which malignancy is seen at increased frequency in people working in the ruber industry?
Bladder cancer - related to exposure to aromatic amines
Q: Tumor markers
Breast cancer CA15-3, CA27-29m and CEAOvarian cancer CEA, CA-125Testicular cancer b-HCG, AFPHepatocellular carcinoma AFP
Q: What is Li-Fraumeni Syndrome?
High familial incidence of tumors of soft tissue, breast, brain, bone, leuemia, and adrenal cortex
Q: What chromosomal abnormality is associated with young men with malignant mediastinal germ cell tumors
Kleinfelter’s syndrome
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