Soluble mesothelin-related Peptide and osteopontin as markers of response in malignant mesothelioma.
OBJECTIVE
In malignant mesothelioma (MM), radiologic assessment of disease status is difficult. Both soluble mesothelin-related peptide (SMRP) and osteopontin (OP) have utility in distinguishing MM from benign pleural disease. We evaluated whether SMRP and OP also correlated with the disease course of MM.


METHODS
Serial plasma samples from patients with MM were prospectively collected, and SMRP and OP levels were measured. Radiologic tests across time periods showing disease progression, stability, or shrinkage were compared with corresponding changes in SMRP/OP levels.


RESULTS
From 41 patients, 165 samples were collected (range, 2 to 10; median 4). At study entry, 37 of 41 patients had measurable disease, of whom 92% (34 of 37) had elevated baseline SMRP levels; four of 41 patients had no evidence of recurrence and each had normal baseline SMRP levels. In 21 patients receiving systemic therapy, percentage change in SMRP more than 10% correlated with the radiologic assessment by a trained thoracic radiologist (P < .001), by formal Response Evaluation Criteria in Solid Tumors (RECIST; P = .008), or by modified RECIST (P < .001). All seven patients who underwent surgical resection with negative margins had elevated preoperative SMRP levels that fell to normal postoperatively. Rising SMRP was observed in all patients with radiologic disease progression. No associations were found with OP.


CONCLUSIONS
Percentage changes in SMRP levels, but not changes in OP levels, are a potentially useful marker of disease course. These findings should be validated prospectively for a role as an objective adjunctive measure of disease course in both clinical trials and clinical practice.
Wheatley-Price
Paul
P
Princess Margaret Hospital, Toronto, Ontario, Canada.
Yang
Boming
B
Patsios
Demetris
D
Patel
Devalben
D
Ma
Clement
C
Xu
Wei
W
Leighl
Natasha
N
Feld
Ronald
R
Cho
B C John
BC
O'Sullivan
Brenda
B
Roberts
Heidi
H
Tsao
Ming Sound
MS
Tammemagi
Martin
M
Anraku
Masaki
M
Chen
Zhuo
Z
de Perrot
Marc
M
Liu
Geoffrey
G
D014408:Biomarkers, Tumor / Q000097:blood; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D000090204:Mesothelin; D008654:Mesothelioma / Q000097:blood*; D053495:Osteopontin / Q000097:blood*; D010534:Peritoneal Neoplasms / Q000097:blood*; D010997:Pleural Neoplasms / Q000097:blood*; D011379:Prognosis; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D053495:Osteopontin; D000090204:Mesothelin