1. Occupational cancer A. H. Mehrparvar, MD
Occupational Medicine department
Yazd University of Medical Sciences

2. Importance One in every 2 or 3 individuals develop cancer
5-10% of all cancers are occupational
Most occupational cancers are preventable

3. Carcinogenesis Carcinogens: 2 types Initiator: Promoter:
Carcinogenic alone
Covalently bind to DNA (irreversible alterations)
No threshold dose
Single exposure may be sufficient
Promoter:
Active after initiator exposure
Act by induction of cellular proliferation
Threshold exist
Repeated exposures required

4. Carcinogens IARC groups: Group 1: carcinogenic to humans (benzene)
Group 2A: probably carcinogenic to humans (acrylonitrile)
Group 2B: possibly carcinogenic to humans (chloroform)
Group 3: not classifiable
Group 4: probably not carcinogenic

5. Important industrial processes associated with human cancer
Al production
Boot and shoe manufacturing
Coke production
Furniture manufacture
Nickel refining
Rubber industry
Mining
Petroleum refining

6. Important occupational carcinogens
Asbestos
Benzene
Beryllium
Cadmium
Ionizing radiation
Nickel
Radon
Strong inorganic acids
Vinyl chloride
PAH
Silica (?)

7. Occupational cancers Lung Mesothelioma Skin Nasal cavity Larynx
Bladder
Hepatic angiosarcoma
Hematologic

8. Lung cancer Four major types: Clinical findings: Paraclinic:
SCC, adenocarcinoma, large-cell carcinoma, small-cell carcinoma
Clinical findings:
Cough, hemoptysis, dyspnea, weight loss
Findings of tumor spread
Tracheal obstruction, esophageal compression
Paraclinic:
CXray: mass lesion, pulmonary infiltrate, adenopathy CT
Sputum cytology
Bronchoscopy and biopsy
Transthoracic FNA Biopsy
Open biopsy
Surveillance:
Serial CXray (?)
Serial sputum cytology (?)

10. Lung cancer Occupational exposures: Asbestos: Radon: PAH: Ni: Cr: As:
Mining
Insulation
textile
Radon:
Uranium mining
Indoor pollution
PAH:
Al reduction
Rubber work
Petrochemical plants, petroleum refinery
Ni:
Ni mining, refining
Cr:
Chromate production
As:
As pesticide
Copper, lead, zinc smelting

11. Mesothelioma Tumor of the pleura or peritoneum Clinical findings:
Persistent gnawing chest pain radiating to shoulder or arm
Dyspnea on exertion
Dry cough
Weight loss
Paraclinic:
Pleural thickening, pleural effusion in chest CX-ray or CT
Pleural fluid cytologic examination
Thoracotomy with multiple biopsies

13. Mesothelioma has an important differential diagnosis
Occupational exposures:
Asbestos:
Mining
Construction work
Insulation
Roofing
Textile
Note:
Mesothelioma has an important differential diagnosis
metastatic tumors

14. Skin cancer Two types: Melanoma Nonmelanomatous SCC BCC Bowen disease
Premalignant entities (solar keratoses)

15. BCC
Nodular or nodular-ulcerative lesion on the skin of head and neck and 10% on trunk
Smooth, shiny, translucent with telangiectatic vessles
Local invasion, rare metastasis
40% of tumors in shaded areas

19. SCC Usually a pre-malignant stage: In-situ carcinoma: Areas:
Rough, reddened placque on sun-exposed areas
In-situ carcinoma:
Well-demarcated slightly raised erythematous placque with scaling
Areas:
Almost always on sun-exposed areas: tip of nose, forehead, lower lip, back of the hands

21. Occupational exposures:
UV:
Outdoor workers
Arsenic:
As pesticide production and use
Cu, Zn, Pb smelting
PAHs:
Al reduction
Rubber work
Ionizing radiation:
HCWs
Uranium miners

22. Nasal cavity and sinuses
Occupational exposures:
Wood dust
Boot and shoe manufacturing
Furniture workers
Textile workers
Ni:
Nickel refinery workers
Cr:
Chromate manufacturing
Metal plating
Isopropyl alcohol:
Laboratory workers

23. Clinical findings: Paraclinic: Unilateral nasal obstruction
Non-healing nasal ulcer
Occasional nasal bleeding
Paraclinic:
Flexible nasoscope
CT scan

24. Larynx Occupational exposures: Asbestos: Clinical findings:
Mining
Construction work
Insulation
Roofing
Textile
Clinical findings:
Hoarseness, difficulty in swallowing, lump in the throat
Paraclinic:
Lateral neck X-ray, CT scan

26. Bladder Occupational exposures: Naphthylamine Benzidine (azo dyes)
Textile workers (dye/pigment)
Benzidine (azo dyes)
Dye/pigment manufacturing
Toluidine:
Painters
Rubber manufacturing
Phenacetin:
Hairdressers
Petroleum workers

27. Clinical and paraclinical findings:
Hematuria
Vesical irritability
Diagnosis:
urine cytology
cystoscopy

28. Hepatic angiosarcoma Occupational exposures: Clinical findings:
Vinyl chloride:
PVC production
Arsenic:
As pesticide production and use
Cu, Zn, Pb smelting
Clinical findings:
RUQ abdominal pain
Weight loss
hepatomegaly

29. Paraclinic: Diagnosis: Anemia Prolonged PT Elevated ALP
Elevated ALT, AST
Diagnosis:
Hepatic angiography
Open liver biopsy

30. Hematologic cancers Occupational exposures: Clinical findings:
Benzene:
Rubber workers
Petrochemical workers
Refinery workers
Ionizing radiation:
HCWs
Uranium miners
Nuclear power plant workers
Clinical findings:
Weakness, malaise, anorexia, fever, easy bruisabilirty
Pallor, hepatosplenomegaly, lymphadenopathy, anemia, thrombocytopenia, leukocytosis or leukopenia