Transcript OCCUPATIONAL CANCER

OCCUPATIONAL
CANCER
Dr. Majid Golabadi
Occupational Medicine Specialist
Isfahan University of Medical Sciences
What Is Cancer?
 Cancer is a large group of
diseases (over 200)
characterized by
uncontrolled growth and
spread of abnormal cells.
 The majority of cancers in adults:
 Genetic factors
 Lifestyle
 Environmental and occupational exposure
 Stress
 Sleep disturbances,
 Diet: high fat and low in fruits and vegetables
 Lack of exercise
 Chemicals In Foods
 Smoking – 30% of all cancer deaths, 87% of lung cancer deaths
 Obesity – 50% higher risk for breast cancer in postmenopausal
women, 40% higher risk in colon cancer for men
 Viral Factors
 5-10% of all human cancers are thought to be caused by
occupational exposure to carcinogens
 Carcinogen: Any chemical , physical or biologic agent present
at the workplace which increases the risk of cancer among
exposed workers
Stages in Tumor Development
1. Initiation
 Cancers come from an abnormal cell (mutation in
DNA)
2. Promotion
 To a benign or preneoplastic tumor
3. Progression
 To a malignant tumor
Carcinogens
 Initiator
 Promoter
 Complete Carcinogens
 Medical surveillance :
 Occupational cancers are completely preventable
 Induction-latency period
 3-5 years for radiation or toxin induced leukemias
 40 or more years for some cases of asbestos-
induced mesothelioma
 For Solid tumors usually 10-25 years
 There is controversy about the existence of threshold
doses for carcinogenic agents
OCCUPATIONAL CANCER
 Avoid the use of chemical in IARC groups 1 and 2A
 Use agent in group 2B only with very tight controls
when there are no viable alternatives
OCCUPATIONAL HUMAN CARCINOGENS
GROUP 1 (IARC) CLASSIFICATION
Arsenic
Lung, Skin, Liver
Asbestos
Benzene
Beryllium
Cadmium
Pleura & peritoneum, Lung, Larynx, GI
Leukemia
Lung
Lung
Chromium
Coal tar
Mustard gas
Lung
Skin, Scrotum, Lung
Lung
Nickel
Solar radiation
Lung, Nasal sinus
Skin
Vinyl chloride
Liver
Selected industrial processes causally
associated with human cancer
Industrial
process
Agent
Cancer site
Aluminum
production
Shoe
manufacture
Iron and steel
founding
PAH
Lung,bladder
Benzene
Leukemia
PAH,Silica
lung
Aromatic amines,
solvents
Bladder, leukemia
Rubber industry
‫عوامل زیان آور شغلی‬
 LUNG
 MESOTHELIOMA
 NASAL CAVITY & SINUSES
 LARYNX
 BLADDER
 LIVER
 SKIN
 HEMATOLOGIC
LUNG CANCER
LUNG CANCER
 The currently accounts for almost 30% of all cancer
deaths
 The most preventable risk factor: cigarette smoking
 In occupations with high prevalence of smoking
 There is no one cell type that is pathognomonic of an
occupationally related lung cancer
 Asbestos
 Radon
Chloromethyl ethers
 PAHs
 Chromium
 Nickel
 Arsenic
 Mustard
Asbestos
(Asbestos miners, Textile, Insulation ,filter, Shipyard)
Blue asbestos (Crocidolyte)
White asbestos (Chrysotile)
Brown asbestos (Amosite)
Asbestos
 The accounting for 20% of all deaths in asbestos-
exposed
 7% of all lung cancer is attributable to asbestos
exposure.
 A latency period: 20 years
 Synergic effect with Smoking
 Cigarette smoke: initiator
 Asbestos: promoter
 Adenocarcinoma
Radon
(Uranium mining , Domestic exposure)
Excessive lung cancer in uranium miners is
independent of cigarette smoking, although
exposure to both is synergistic
Polycyclic Aromatic Hydrocarbons (PAHs)
 From the incomplete combustion of coal tar, pitch, oil
and coke
 The scrotal cancer in chimney sweeps
(Dermal exposure to soot)
 Coke oven workers, Roofers, Printers, Truckers, Rubber
plant workers, Asphalt workers
Chloromethyl Ethers
 Chloromethylmethyl ether (CMME)
 Bischloromethyl ether (BCME)
 Bactericides, Pesticides, Dispersing agents, Water
repellents, Flame-proofing agents
 Small cell lung cancer
Arsenic (Organic Arsenic)
 Lead, Copper and Zinc smelting
 Pesticides
Chromium
 Chromate production
Nickel
 Soluble forms
Probably Carcinogenic for lung cancer
 Acrilonitryl
 Beryllium
 Cadmium
 Vinyl chloride
 Formaldehyde
 Acid Sulfuric
Medical monitoring in the workplace
(Screening )
 Periodic examination:
 History , Physical exam, smoke, training
 Symptoms: persistent cough, blood-streaked
sputum, chest pain, Voice change
 Environmental monitoring
 Serial Chest Radiography and Sputum cytology
(OSHA,NIOSH)
 CT Scan (spiral,…..), HRCT
Prevention
 Primary prevention:
 The most effective methods
 Complete avoidance of exposure to the carcinogen
 Identification of etiologic agents in the workplace
 Worker education
Asbestos
 Asbestos miners
 Textile manufacturing
 Insulation and filter production
 Construction workers
 Welders, Plumbers, electricians
 Roofers
 Shipyard workers
MESOTHELIOMA
The latency period:
30 years or more
Cigarette smoking dose not
increase the risk of MM
Symptoms: Persistent gnawing chest pain, dyspnea, dry
cough, weight loss
Pleural effusion, pleural thickening or nodularity, interstitial
pulmonary fibrosis, pleural plaques, pleural calcification
CXRay: Unilateral pleural effusion
CT_Scan: Most sensitive test for pleural surface
Sputum cytology
Thoracentesis
Thorachotomy and thoracoscopy
MESOTHELIOMA
 Treatment:
 Surgical
 Radiotherapy
 Chemotherapy
 Prognosis:
 75% of patients die within 1 year after diagnosis
 Pleura, peritoneal
More frequent in men than women (2:1)
Usually squamous cell histology (50%),
The disease is very uncommon in workers under 50
years of age, and rates increase with age
 Wood and other dusts
(Furniture, Textile, boot and shoe manufacturing, bakes )
Chromium (Nasal septum ulcer and perforation)
(Chromate pigment production , metal plating )
 Nickel
(Nickel refinery workers)
 Isopropyl alcohol, Formaldehyde
(laboratory workers , other industries )
•Owen workers, foundry workers, Radium, Radon, mustard
 Symptoms:
Unilateral nasal obstruction
Non-healing ulcer
Occasional bleeding
A low-grade chronic infection, associated with discharge,
obstruction ,and minor intermittent bleeding
Chronic hypertrophic rhinitis
Dry atrophic nasal mucosa
Nasal polyps
Almost Adenocarcinomas
Prevention
 Primary prevention:
 Complete avoidance of exposure to the carcinogen is the
ultimate goal, but this is not always possible
 Identification of etiologic agents in the workplace
 Worker education
Laryngeal cancer is primarily a disease of older workers.
Cancer of the larynx is much more common than sinonasal
cancer
Cigarette smoking and alcohol abuse are the primary
etiologic factors
Much more frequent in men than women (4.5:1) ,usually
middle aged or older
Asbestos
 Asbestos miners
 Textile manufacturing
 Insulation and filter production
Shipyard workers
 Hoarseness is an early presenting symptom
 Usually squamous cell histology
 At the time of diagnosis:
60% localized
30% regional spread
10% distance metastases
 40% supra-glottic, 59% glottic, 1% sub-glottic
Prevention
 Primary prevention:
 Complete avoidance of exposure to the carcinogen is the
ultimate goal, but this is not always possible
 Identification of etiologic agents in the workplace
 Worker education
 Periodic examination:
 History , Physical exam, smoke, training
 Environmental monitoring (limits)
BLADDER CANCER
 5% of all malignant tumors
 M/F = 2/1
 Cigarette smoking is the most important etiologic factor (60%)
 Water infected to pesticides and other chemicals
 The latency period: mean of 20 years
 Presenting complaints of hematuria and vesical irritability
 Diagnosis by urine cytologic examination and cystoscopy
 Naphtylamine (Textile workers, Dye & pigment manufacture,
Rubber manufacture)
 4-Aminobiphenyl (Tire & Rubber manufacture)
 Benzidine (Dye & pigment manufacture)
 Chlornaphazine (leather worker)
 O-toluidine (Painters, Textile workers , Bootblacks)
 Phenastin (Petroleum workers, Hairdressers)
High exposed workers
 Textile workers,
 Dye & pigment manufacture,
 Tire & Rubber manufacture
 leather worker
 Painters,
 Bootblacks
 Petroleum workers,
 Hairdressers
4- Aminobiphenyl
Chlornaphazine
Benzidine
Pathogenesis & Pathology
 Body exposure via GI, Dermal or Respiratory
 Caused by contact of the bladder epithelium with
carcinogens in the urine
 The bladder is exposed to higher concentration of these
materials than other body tissues
 Urothelial tumors:
 90% transitional cell type
 6-8 % squamous cell
 2% adenocarcinoma
Clinical findings
 The most common:
 Hematuria 80%
 Painless, gross, and intermittent
 20%: the vesical irritability alone, with increased frequency,
dysuria, urgency and nocturia
 U/A: RBC, Blood
 Anemia, Uremia
Prognosis
 Prognosis varies with the stage of the disease
 Superficial:
 The excellent 5-year survival
 Muscle invasion:
 40-50% of patients 5-year survival
 Local spread of disease in the pelvis:
 10-17% of patients survive 5 years
Screening
 Urine cytology and U/A:
 Screening tool
 Sensitivity (75%),specifity (99.9%)
 Used to screen only certain at risk occupations
 The screening of high-risk patients may result in a
significant reduction of the stage of disease at diagnose,
with improved long-term survival
 Vinyl chloride (PVC production)
 Arsenic (Pesticide , Copper ,Lead , Zinc smelting , Wine
maker, Fowler)
 Thorotrast
Hepatic Angiosarcoma
 Angiosarcoma of the liver is a rare tumor
 M/F: 4/1
 Major exposure to vinyl chloride
Sign & symptoms
 RUQ abdominal pain, weight loss
 Hepatomegaly on physical examination
 Diagonisis by hepatic arterogram and liver biopsy
Clinical Findings
 Non-specific:
 Fatigue, weakness, and weight loss are seen in 25-50% of
patients
 The some patients may be asymptomatic
 Abdominal pain is the most common symptom,
usually in the RUQ
 Phx:
 Hepatomegaly with ascites
 Jaundice
 Splenomegaly , abdominal mass, tenderness
Laboratory findings
 A mild anemia, target cells and schistocytes
 Leukocytosis and thrombocytopenia (1/2 patients)
 Prolonged PT
 Almost all patients: abnormality of liver function
testing
 ALT, AST and ALP
Screening tests
 Periodic testing:
 History and physical examination
 CBC, LFT (SGOT, SGPT, ALP)
 UV radiation (Outdoor workers, welding arc)
 PAHs (coal tar workers , Electrode production , Pigment
Industry , Roofers , Shale oil worker)
 Ionizing radiation (Uranium miners, Health care
workers, Military personnel)
 Arsenic (Pesticide , Copper ,Lead , Zinc smelting)
Chronic inflamation
UV Radiation
 Major risk is ultraviolet radiation
 There are 4.8 million outdoor workers in the USA
(agriculture,…)
 The estimated 300000 workers are exposed to
industrial radiation sources
(welding arc, germicides and printing processors)
PAHs
Ionizing radiation & skin cancer
 High risk: more than 1000 cGy
 Early radiation workers with heavy exposure:
 Predominantly SCC
 The hands and feet and occasionally on the face
 More recently, basal cell cancers have been described
following repeated occupational exposures
Arsenic
 Punctate keratoses of the palms and soles and
hyperpigmentation are frequently seen
 Ionizing radiation (Nuclear power
plant worker, Health care worker, Military
personnel)
 Benzene (Petrochemical and refinery
worker , Rubber worker)
Ionizing radiation & aplastic
anemia
 Dose dependent
 Large dose & long term (small amount)
 Risk:


Increased until 3-5 years after exposure
After which there is a marked decline in incidence
 Treatment:

Bone marrow transplantation,hematopoietic growth
factors
Benzene & leukemia
 Benzene is a cyclic hydrocarbon obtained in distillation
of petroleum and coal tar
 It is used widely in chemical synthesis in many
industries
 Explosives,soap,perfums, Drugs,dyes,rubber,shoes
Benzene & leukemia
 Workers exposed for 5 years or more had a 21-fold increased
risk of death from leukemia
 Aplastic or hypoplastic anemia
 Acute , chronic (30 years after exposure)
 Exposure to 100 ppm cause cytopenia