Asbestos burden predicts survival in pleural mesothelioma.
BACKGROUND
Malignant pleural mesothelioma (MPM) is a rapidly fatal asbestos-associated malignancy with a median survival time of <1 year following diagnosis. Treatment strategy is determined in part using known prognostic factors.


OBJECTIVE
The aim of this study was to examine the relationship between asbestos exposure and survival outcome in MPM in an effort to advance the understanding of the contribution of asbestos exposure to MPM prognosis.


METHODS
We studied incident cases of MPM patients enrolled through the International Mesothelioma Program at Brigham and Women's Hospital in Boston, Massachusetts, using survival follow-up, self-reported asbestos exposure (n=128), and a subset of cases (n=80) with quantitative asbestos fiber burden measures.


RESULTS
Consistent with the established literature, we found independent, significant associations between male sex and reduced survival (p<0.04), as well as between nonepithelioid tumor histology and reduced survival (p<0.02). Although self-reported exposure to asbestos was not predictive of survival among our cases, stratifying quantitative asbestos fiber burden [number of asbestos bodies per gram of lung (wet weight)] into groups of low (0-99 asbestos bodies), moderate (100-1,099), and high fiber burden (>1,099), suggested a survival duration association among these groups (p=0.06). After adjusting for covariates in a Cox model, we found that patients with a low asbestos burden had a 3-fold elevated risk of death compared to patients with a moderate fiber burden [95% confidence interval (CI), 0.95-9.5; p=0.06], and patients with a high asbestos burden had a 4.8-fold elevated risk of death (95% CI, 1.5-15.0; p<0.01) versus those with moderate exposure.


CONCLUSIONS
Our data suggest that patient survival is associated with asbestos fiber burden in MPM and is perhaps modified by susceptibility.
Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
Brock C
BC
Christensen
John J
JJ
Godleski
Cora R
CR
Roelofs
Jennifer L
JL
Longacker
Raphael
R
Bueno
David J
DJ
Sugarbaker
Carmen J
CJ
Marsit
Heather H
HH
Nelson
Karl T
KT
Kelsey
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001194:Asbestos / Q000032:analysis* / Q000378:metabolism; D004781:Environmental Exposure / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D008654:Mesothelioma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008875:Middle Aged; D010997:Pleural Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate
D001194:Asbestos