Smoking-associated fibrosis and pulmonary asbestosis

Figures & data

Figure 1 Asbestos bodies.

Notes: Prussian blue-stained section from a subject with asbestos exposure and interstitial fibrosis. Original magnification ×200.

Figure 2 Smoking-associated interstitial fibrosis.

Notes: Hematoxylin and eosin stained section. Note the widening of alveolar septae by dense eosinophilic fibrosis with a paucity of inflammatory cells. Original magnification ×200.

Table 1 Subjects’ profession, duration of asbestos exposure, smoking status, and type of malignancy

Profession	N	Mean age (yrs)	Mean exposure (yrs)	Exposure time range*	Smokers (%)	Mean pack-years	N with lung cancer (%)	N with mesothelioma (%)
Boilermaker	9	70	25	1936–1988	83	44	5 (56)	3 (33)
Brakes-mechanic	2	60	24	1943–1999	100	35	2 (100)	0
Bricklayer	3	58	30	1939–1980	67	33	2 (67)	0
Carpenter	5	69	31	1936–1989	100	59	4 (80)	1 (20)
Construction	3	67	21	1949–1986	100	30	2 (67)	1 (33)
Electrician	11	72	30	1939–1991	80	45	7 (64)	4 (36)
Insulator	9	72	24	1941–1996	100	26	3 (33)	5 (56)
Laborer	26	70	28	1940–1999	90	47	19 (73)	3 (12)
Machinist	7	63	22	1930–1995	100	56	4 (57)	3 (43)
Mason	5	64	24	1940–1996	75	62	4 (80)	1 (20)
Mechanic/maintenance	13	63	22	1936–2000	100	43	5 (38)	8 (62)
Millwright	4	68	25	1940–1982	100	46	3 (75)	1 (25)
Operator	11	69	34	1943–2000	100	51	9 (82)	1 (9)
Plumber/pipefitter	17	68	29	1936–1999	77	47	7 (41)	10 (59)
Shipyard	17	68	24	1939–2002	100	46	5 (29)	12 (71)
Sheetmetal	3	70	21	1935–1980	50	75	1 (33)	2 (67)
Steelworker	2	68	29	1943–1983	100	30	2 (100)	0
Welder	8	69	30	1943–1993	100	55	5 (63)	3 (38)
Laundry	11	51	18	1935–1993	14	50	0	11 (100)
Other	20	72	26	1947–1986	100	47	12 (60)	8 (40)
Total	186	68	27	1930–2002	88	46	101 (54)	77 (41)

Notes: The percentage of smokers is based on a total of 143 subjects for whom a smoking history was available.

* Exposure time range is the range of years in which each group reported asbestos exposure – the vast majority reported significant exposure time before 1975. Totals are indicated in bold font.

Abbreviations: N, number of subjects; yrs, years.

Table 2 Subtypes of malignancy diagnoses within the cohort

Malignancy	Number (%)
Lung
Adenocarcinoma	37 (20)
Squamous cell carcinoma	22 (12)
Non-small cell lung carcinoma	20 (11)
Small cell carcinoma	17 (9)
Other	5 (3)
Mesothelioma	77 (41)
No malignancy	8 (4)
Total	186

Notes: “Other” lung malignancies included large cell neuroendocrine carcinoma, carcinoid, and adenosquamous carcinoma. Total number of subjects indicated in bold.

Figure 3 Flow chart showing the breakdown of cases with and without histologic and radiologic evidence of asbestosis and fibrosis. *<1 and ≥1 refer to ILO profusion.

Abbreviation: ILO, International Labor Organization.

Table 3 Correlation of ILO profusion, histopathologic evidence of asbestosis, and smoking

	ILO profusion					Total
	ILO ≥1		ILO <1		Unknown
	N (% smokers)	Smoking status not available (N)	N (% smokers)	Smoking status not available (N)
Asbestosis	6 (83)	0	1 (100)	1	0	8
No asbestosis	16 (100)	2	27 (89)	12	2	59
Not evaluable*	29 (100)	9	60 (80)	20	1	119
Total	51 (98)	11	88 (83)	33	3	186

Notes:

* Tissue sampling inadequate to evaluate asbestos status histologically. Percentage with a history of cigarette smoking shown in parentheses. Totals shown in bold font.

Abbreviations: N, number of subjects; ILO, International Labor Organization.

Table 4 Demographics of 24 cases with ILO profusion ≥1 and sufficient tissue for histopathologic evaluation

Histologic diagnosis	N	Average age	Male/female	Mean potential years of asbestos exposure (range)	% smokers	Mean pack-years
Asbestosis	6	72	6/0	25 (14–34)	83	41
No asbestosis	18	69	18/0	25 (7–40)	100*	53

Note:

* Two cases had no available smoking history status but had histopathologic changes consistent with smoking. Abbreviation: ILO, International Labor Organization.