© 2007 The Authors
214 Journal compilation © 2007 The International Society for Diseases of the Esophagus
Diseases of the Esophagus (2008) 21, 214–219
DOI: 10.1111/j.1442-2050.2007.00754.x
Blackwell Publishing Asia
Original article
Prognostic role of immunosuppressive acidic protein in patients with
esophageal cancer
M. Kogure, S. Kashimura, S. Matsuyama, S. Ohtani, Z. Saze, Y. Odashima, T. Saitoh, N. Soeta, F. Osuka,
Y. Hoshino, T. Saito, S. Terashima, M. Terashima, M. Gotoh
Department of Surgery 1, Fukushima Medical University, Fukushima, Japan
SUMMARY. Immunosuppressive acidic protein (IAP) suppresses several immune responses in vivo and in vitro,
and high preoperative IAP levels could predict the impairment of the host’s immunity. In this study prognostic
significance of preoperative IAP levels was investigated in 68 esophageal cancer patients with curative resection
and eight with non-curative resection. The curative group had significantly lower levels than the non-curative
group (432 ± 183 μg/mL vs. 739 ± 235 μg/mL, P < 0.0001). The IAP levels were associated with T-status
(P < 0.0001), lymphatic invasion (P < 0.05), and p-stages (P < 0.0001). When 5-year survival rate of patients
with curative resection was compared by setting various cutoff values of IAP between high and low IAP
groups, several cutoff points (400–580 μg/mL) were revealed to be significantly associated with survival. Set-
ting cutoff value of IAP to 560 μg/mL resulted in a most significant difference of 5-year survival rate of
patients between the high and low IAP groups (13.9% and 61.5%, P < 0.0001). These data indicate that pre-
operative IAP level is a useful parameter to predict the prognosis of esophageal cancer patients after curative
resection.
KEY WORDS : immunosuppressive acidic protein, esophageal cancer, prognosis.
INTRODUCTION
Immunosuppressive acidic protein (IAP) was first
isolated from ascitic fluid and serum of cancer patients
as a non-specific and soluble immunosuppressive
factor with a molecular weight of 50 000.
1
It has
been shown that IAP suppresses several immune
responses in vivo and in vitro including both phyto-
hemagglutinin (PHA)-induced lymphocyte blast
formation and mixed lymphocyte reaction, and
belongs to the alpha-1 acid glycoproteins.
2,3
Two
mechanisms are known to be involved in IAP
production. In cancer patients, IAP is produced in
the lymphocytes and macrophages and is associated
with tumor progression.
4
In the inflammatory
response, IAP is produced by hepatocytes with IL-6
stimulation.
5
It is well known that IAP has strong
immunosuppressive activity.
In our previous study, it was revealed that the
preoperative serum IAP level has good association
with the status of progression in gastric cancer, and
may be useful as a prognostic factor.
6
However, few
reports have been seen in association with IAP and
esophageal cancer patients. Here we show that
preoperative IAP levels can be a prognostic factor
for patients with esophageal cancer after radical
operation.
MATERIALS AND METHODS
Subjects
This study included 76 patients, 41–79 years of age
(mean age, 63.2 years) with previously untreated
esophageal cancer, whose serum IAP levels were
measured between April 1990 and March 2000 in
the Department of Surgery 1, Fukushima Medical
University, Japan. After serum IAP levels were
measured, curative resection was performed in 68
patients. In the curative group, preoperative or
postoperative treatment including chemotherapy
and/or radiation was administered to 58 patients
Address to correspondence to: Michihiko Kogure, MD,
Department of Surgery I, Fukushima Medical University,
Fukushima, 1 Hikarigaoka Fukushima, 960-1295, Japan.
Email: kogure@fmu.ac.jp
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