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In vitro cytotoxicity and induction of apoptosis by ruthenium(II) complexes in HL-60 and K-562
Hepatol Int (2015) 9:330–336
DOI 10.1007/s12072-015-9620-6
ORIGINAL ARTICLE
Natural history of large regenerative nodules and dysplastic
nodules in liver cirrhosis: 28-year follow-up study
Tsunenobu Sato • Fukuo Kondo • Masaaki Ebara • Nobuyuki Sugiura •
Shinichiro Okabe • Masahiko Sunaga • Masaharu Yoshikawa • Eiichiro Suzuki •
Sadayuki Ogasawara • Yusuke Shinozaki • Yoshihiko Ooka • Tetsuhiro Chiba •
Fumihiko Kanai • Takashi Kishimoto • Yukio Nakatani • Toshio Fukusato •
Osamu Yokosuka
Received: 18 October 2014 / Accepted: 31 January 2015 / Published online: 3 March 2015
Ó The Author(s) 2015. This article is published with open access at Springerlink.com
Abstract
Background and aims Some follow-up studies of large
regenerative nodules (LRNs) and dysplastic nodules (DNs)
were reported previously. However, the pre-malignant
potentiality of LRNs has remained controversial up to now.
No LRNs showed malignant transformation in our previous
study. We aimed to evaluate the pre-malignant potentiality
of LRNs and DNs with a greater number of cases and
longer follow-up periods.
Methods From 1982 to 2005, 1,500 consecutive nodular
lesions up to 2 cm in diameter were subjected to US guided
thin-needle biopsy in cirrhotic patients at Chiba University
Hospital. Of these lesions, 68 LRNs in 60 cases and 20
DNs in 22 cases were followed up for more than 6 months
without any anti-cancer therapy. The last US examination
was in 2010. The total study period was 28 years. We
analyzed the histological findings and the clinical data of
all cases retrospectively. The outcome of the lesions was
examined.
Results The mean follow-up period was 38.9 (16–119)
months in LRNs and 31.9 (6–101 months) in DNs. Rate of
nodule enlargement was higher in DNs (8/24 nodules,
33 %) than LRNs (11/68 nodules, 16 %), (p = 0.0743, not
significant). Rate of malignant transformation was also
higher in DNs (10/24 nodules, 42 %) than LRNs (9/68
nodules, 13 %), (p = 0.0040, significant). The rate of
disappearance in images was similar between LRNs and
DNs.
Conclusions We should recognize LRN as low risk premalignant lesions whereas DNs as high risk lesions.
T. Sato M. Yoshikawa E. Suzuki S. Ogasawara Y. Ooka
T. Chiba F. Kanai O. Yokosuka
Department of Gastroenterology and Nephrology, Graduate
School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku,
Chiba City, Chiba 260-8670, Japan
e-mail: tsune-sato@cnc.jp; ccmc.tsato@gmail.com
O. Yokosuka
e-mail: yokosukao@faculty.chiba-u.jp
M. Yoshikawa
e-mail: yoshikawa@faculty.chiba-u.jp
E. Suzuki
e-mail: eiichiro0709@hotmail.com
S. Ogasawara
e-mail: sadahisa@me.com
Y. Ooka
e-mail: ooka-y@umin.ac.jp
T. Chiba
e-mail: techiba@faculty.chiba-u.jp
F. Kanai
e-mail: kanaif@faculty.chiba-u.jp
123
Keywords Large regenerative nodule Dysplastic
nodule Natural history Malignant transformation
T. Sato M. Sunaga
Department of Gastroenterology, Chiba Central Medical Center,
1835-1 Kasoricho, Wakaba-ku, Chiba City, Chiba 264-0017,
Japan
e-mail: sunaga-m@umin.ac.jp
F. Kondo (&)
Department of Pathology, Teikyo University Hospital, 2-11-1
Kaga, Itabashi-ku, Tokyo 173-8606, Japan
e-mail: fkondo55@med.teikyo-u.ac.jp
M. Ebara S. Okabe
Department of Gastroenterology, Matsudo City Hospital, 4005
Kamihongo, Matsudo City, Chiba 271-8511, Japan
e-mail: masaaki-ebara@nifty.com
S. Okabe
e-mail: okabeshin1966@yahoo.co.jp
Hepatol Int (2015) 9:330–336
Abbreviations
LRN Large regenerative nodule
DN
Dysplastic nodules
HCC Hepatocellular carcinoma
US
Ultrasound
CT
Computed tomography
MRI Magnetic resonance image
HCV Hepatitis C virus
HBV Hepatitis B virus
Introduction
Although several follow-up studies of large regenerative
nodules (LRNs) and dysplastic nodules (DNs) have been
reported [1–9], the pre-malignant potentiality of LRNs is
still controversial. No LRNs showed malignant transformation in our previous study [1], whereas some authors
reported that LRNs were pre-malignant [3, 8, 9]. However,
these earlier reports are not easily compared, as the histological criteria of well differentiated hepatocellular carcinoma (HCC), DN and LRN were lacking universal
consensus at that time [10, 11]. In addition, the numbers of
nodules were not so many and the follow-up periods were
not so long. A few reports studied over 90 nodules [8, 9],
with the others studied less than 40 nodules [1–6]. In four
of the nine previous studies, the longest follow-up period
was less than 5 years. If the numbers of nodules and the
lengths of the follow-up periods had been greater, the results might also have been different.
N. Sugiura Y. Shinozaki
Department of Internal Medicine, National Hospital
Organization Chiba Medical Center, 4-1-2 Tsubakimori,
Chuo-ku, Chiba City, Chiba 260-8606, Japan
e-mail: sugiura@nho-chiba.hosp.go.jp
Y. Shinozaki
e-mail: y-shino@alpha.ocn.ne.jp
T. Kishimoto
Department of Molecular Pathology, Graduate School of
Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku,
Chiba City, Chiba 260-8670, Japan
e-mail: tkishi@faculty.chiba-u.jp
Y. Nakatani
Department of Diagnostic Pathology, Graduate School of
Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku,
Chiba City, Chiba 260-8670, Japan
e-mail: nakatani@faculty.chiba-u.jp
T. Fukusato
Department of Pathology, School of Medicine, Teikyo
University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
e-mail: fukusato@med.teikyo-u.ac.jp
331
In the present study, we studied many more LRNs than
in our previous study, and the follow-up period was also
elongated. DNs were also studied and compared with the
results of LRNs. This is the only study which dealt with
more than 90 nodules smaller than 2 cm in which the
longest follow-up period was more than 5 years.
Materials and methods
From 1982 to 2005, 1500 consecutive nodular lesions up
to 2 cm in diameter were subjected to ultrasound (US)
guided thin-needle biopsy in cirrhotic patients at Chiba
University Hospital. They were diagnosed as 898 HCCs,
108 DNs, 315 LRNs, and 179 other lesions. Of the 108
DNs, 76 DNs were treated according to the patient’s
preference or were confirmed as HCC by imaging diagnosis within 6 months. The remaining 32 DNs were followed up without any anti-cancer therapy. Informed
consent of liver biopsy was taken from each patient.
Within 6 months, eight DNs dropped out. Finally, 24 DNs
from 22 cases were followed up for longer than 6 months.
Similarly, 68 LRNs from 60 cases were followed up for
more than 6 months. The last US examination of this
study was performed in 2010, meaning that the total study
period was 28 years (1982–2010). At this final point, we
analyzed the histological findings and the clinical data of
all cases retrospectively.
The outcome of the lesions (i.e., no change, enlargement
of nodule size, malignant transformation and disappearance
in images) was examined.
Profiles of the cases and nodules are shown in Tables 1
and 2, including age, male/female ratio, pre-existing HCC
nodules, single or multiple lesions, diabetes mellitus (DM),
liver function tests and tumor markers. No significant differences were seen between LRNs and DNs in respect to
these items. As to the causes of cirrhosis in LRNs and DNs,
hepatitis C virus was the most common, followed by
hepatitis B virus. Cases of alcoholic cirrhosis were not
included in this study (Table 1). Median nodule size was
12 mm in both LRNs and DNs (Table 2). Findings of
ultrasound, dynamic CT and MRI were not statistically
different between LRNs and DNs.
Measurement of nodule size
The longer diameter of the nodule shown on the monitor of
the ultrasound (US) was measured. We used a pre-installed
measuring tool in the US instrument. To avoid a measurement error, more than one doctor performed US examination. As a principle, one of them was a wellexperienced (more than 10 years) doctor. In case the longer
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Table 1 Profile of the cases
Hepatol Int (2015) 9:330–336
Characteristic
Large regenerative nodules (LRNs)
Dysplastic nodules (DNs)
Nodule, n
68
24
Case, n
60
22
Age
66 (24–79)
63 (37–71)
0.6080a
Male/female
39/21
18/4
0.1815b
Pre-HCC (?)/(-)
10/44
1/21
0.2730b
Single nodule case, n
55
21
1.0000b
Multiple nodule case, n
5
1
0.8677c
Etiology
Data are shown as median and
range
a
Mann–Whitney test
b
Fisher’s exact test
c
Chi-square test
Table 2 Profile of nodule
p value
HCV
44
16
HBV
8
4
HCV and HBV
1
0
Alcohol
0
0
Others
7
2
DM (?)/(-)
7/53
3/19
1.0000b
Child classification A/B/C
AST (IU/ml)
53/4/3
72 (15–400)
19/1/2
57 (34–197)
0.7529c
0.6787a
ALT (IU/ml)
69 (11–466)
63 (27–307)
0.5641a
Platelet (910 /ll)
11.0 (3.7–20.9)
12.1 (5.5–21.0)
0.2231a
AFP (ng/ml)
8.2 (1.8–657)
10.5 (3.7–55.3)
0.5040a
PIVKA-II (mAU/ml)
18 (\ 10–31)
15 (\ 10–24)
0.1755a
p value
4
Parameter
Large regenerative nodules (LRNs)
Dysplastic nodules (DNs)
Nodule, n
68
24
Median size (diameter, mm)
12 (8–20)
12 (8–17)
0.8891a
US, hypo/hyper
53/15
14/10
0.1071b
Plain phase, high/iso/low
1/58/6
0/18/4
0.4521c
Arterial phase, high/iso/low
4/54/7
0/19/5
0.2434c
Late phase, high/iso/low
2/52/11
0/19/5
0.6411c
T1WI, high/iso/low
7/33/2
4/7/0
0.2996c
T2WI, high/iso/low
6/33/3
0/10/1
0.4109c
Dynamic CT
a
Mann–Whitney test
b
Fisher’s exact test
c
Chi-square test
MRI
diameter increased 1.5 times the former size, we interpreted that the diameter increased significantly.
Definition of malignant transformation
Histological and/or imaging features which suggest HCC
were used as the criteria of malignant transformation.
We evaluated nodule enlargement and malignant transformation independently. A nodule which showed enlargement of the size without malignant features in histological
and imaging studies was simply interpreted as enlargement,
whereas a nodule which showed malignant changes without
enlargement was classified as malignant transformation.
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Statistical analysis
In order to compare the various data of LRNs and DNs, the
following statistical methods were used.
Mann–Whitney test: median age, median nodule size,
AST, ALT, platelet, AFP, PIVKA-II
Fisher’s exact test: male/female ratio, pre-existing HCC
nodules, single or multiple lesions, US findings of
nodules, diabetes mellitus
Chi-square test: etiology of cirrhosis, CT and MRI
findings of nodules, occurrence of new HCC lesions
remote from nodules, Child classification
Hepatol Int (2015) 9:330–336
Log-rank (Mantel–Cox) test: rate of nodule enlargement,
rate of progression to malignancy, rate of disappearance
on ultrasonography
p value less than 0.05 was recognized as significant.
Results
The mean follow-up period was 38.9 (16–119) months for
LRNs and 31.9 (6–101 months) for DNs. Of the 68 LRNs,
11 showed enlargement and 35 became undetectable on
US. Of the 24 DNs, eight showed enlargement and eight
disappeared on US. All of the LRNs and DNs which disappeared remained undetectable by other types of imaging
(CT and MRI) during the additional follow-up periods. As
for the disappeared nodules, HCCs were not found in their
loci. Finally, malignant transformation was proven in nine
LRNs and ten DNs.
Comparison of outcomes of LRNs and DNs
Rate of nodule enlargement
Figure 1 shows the rates of nodule size enlargement in both
LRNs and DNs. Using the Kaplan–Meier method, the rates
of enlargement at 50 months and 100 months were 13.7
and 46 % in LRNs and 26.5 and 69.4 % in DNs, respectively. Nodule enlargement was more frequently found in
DNs than in LRNs, although the difference was not significant [p = 0.0743, Log-rank (Mantel–Cox) Test].
333
at 50 months and 32 % at 100 months, while that of DNs
was 40 % at 50 months and 75 % at 100 months, using the
Kaplan–Meier method. Progression to malignancy was
more frequently found in DNs than in LRNs, with the
difference being statistically significant [p = 0.0040, Logrank (Mantel–Cox) Test].
Figure 3 shows a representative case of proven malignant transformation of LRN. The patient was a 60-year-old
male, HCV antibody-positive, with liver cirrhosis. A hypoechoic nodule 13 mm in diameter was detected by US
(Fig. 3a). Biopsy diagnosis was a large regenerative nodule
(Fig. 3b). The nodule showed no change in size and
character for 26 months (Fig. 3c), but at 32 months, the
nodule had grown to 23 mm (Fig. 3d). Rebiopsy revealed
its progression to well differentiated HCC (Fig. 3e). This
LRN kept a benign nature for 26 months and then progressed to HCC within another 6-month period.
Comparisons of initial profiles including age, serum
blood test and tumor markers in cases with and without
malignant transformation of nodules are shown in Table 3.
Among these items, only one item, i.e. DN/LRN, was
proven to be related to malignant transformation
(p = 0.0066, Fisher’s exact test). Other items such as,
nodule size, imaging findings, age, liver function tests,
etiology of liver cirrhosis, tumor markers and association
of DM were not related to malignant transformation.
Disappearance on ultrasonography
The rates of progression to malignancy in LRNs and DNs
are shown in Fig. 2. The rate of LRNs to HCC was 13.6 %
Figure 4 shows the rate of detection of LRNs and DNs by
US. During the follow-up period, some LRNs and DNs
became undetectable by US, and they were also not detectable by other imagings (CT, MRI). The detection rates
of nodules at 50 and 100 months were 50.3 and 17.8 % in
Fig. 1 Rate of nodule enlargement. Nodule enlargement was more
frequently found in dysplastic nodules than in large regenerative
nodules, although the difference was not significant [p = 0.0743,
Log-rank (Mantel–Cox) test]. DN dysplastic nodule, LRN large
regenerative nodule
Fig. 2 Rate of progression to malignancy. Malignant transformation
was more frequently found in dysplastic nodules than in large
regenerative nodules. The difference was statistically significant
[p = 0.0040, Log-rank (Mantel–Cox) Test]. DN dysplastic nodule,
LRN large regenerative nodule
Rate of progression to malignancy
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Hepatol Int (2015) 9:330–336
Fig. 3 An LRN case showing malignant transformation. a A hypoechoic nodule 13 mm in diameter was detected by US (arrows).
b Biopsy specimen showed minimal atypia. Diagnosis was large
regenerative nodule (bar 50 lm). c Size and US findings showed no
change for 26 months (arrows). d At 32 months, the nodule had
enlarged to 23 mm (arrows). e Histological specimen from rebiopsy
showed definite increased cellularity, and diagnosis was well
differentiated HCC (bar 50 lm)
LRNs and 68.5 and 41.1 % in DNs, according to the Kaplan–Meier method. There was no significant difference
between LRNs and DNs. Various clinical data including
DM, liver function tests and tumor markers shown in the
Tables 1 and 3 were not proven to be related to the disappearance of the nodules.
15 % (9 of 60 cases) in LRN cases and 22.7 % (5 of 22
cases) in DN cases. The difference was not statistically
significant (p = 0.4100, Chi-square test).
The occurrence of new HCC lesions was also reported in
our previous study, and was thus confirmed in the present
study.
Occurrence of new HCC lesions remote from nodules
Discussion
Table 4 shows the frequency of occurrence of new HCC
lesions remote from the followed-up nodules. The rate was
A better knowledge of the natural history of small hepatic
nodules including LRN, DN and HCC is important for the
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Hepatol Int (2015) 9:330–336
Table 3 Comparisons of initial
profiles in cases with and
without malignant
transformation of nodules
335
Parameter
Malignant
Non-malignant
p value
Nodule, n
19
73
–
Nodule size (mm)
12 (8–16)
11 (8–20)
0.8644a
US, hypo/hyper
13/6
54/9
0.7727b
DN/LRN
10/9
14/59
0.0066b
Age
63 (24–73)
67 (37–79)
0.4719a
AST (IU/ml)
60 (30–197)
73 (15–400)
0.1835a
58 (11–466)
71 (11–466)
0.1835a
Platelet (910 /ll)
11.7 (7.2–20.9)
11.2 (3.7–16.7)
0.6477a
Child classification/NBNC
12/4/3
54/11/8
0.9680c
AFP (ng/ml)
12.5 (3.1–108.9)
7.9 (1.8–657)
0.5505a
PIVKA-II (mAU/ml)
18 (\10–24)
15 (\10–31)
0.9382a
HCV/HBV/NBNC
12/4/3
54/11/8
0.6469c
DM (?)/(-)
3/16
8/65
0.6912b
Pre-HCC (?)/(-)
1/18
10/64
0.2710b
ALT (IU/ml)
4
Data were shown as median and
range
a
Mann–Whitney test
b
Fisher’s exact test
c
Chi-square test
Fig. 4 Rate of detection on ultrasonography. Rate of detection on
ultrasonography was not significantly different in dysplastic nodules
and large regenerative nodules [p = 0.6037, Log-rank (Mantel–Cox)
test]. DN dysplastic nodule, LRN large regenerative nodule
Table 4 Occurrence cases of new HCC lesions remote from the
nodules
Parameter
LRN
DN
p value
0.4100
Occurrence of new HCC (?)
9
5
Occurrence of new HCC (-)
51
17
management of cirrhotic patients. We formerly investigated the natural history of HCC [12]. Although DN has
been recognized as a pre-malignant lesion of HCC, the premalignant potentiality of LRN had not been clearly described in a number of important publications [10, 11, 13–
15]. In fact, our previous study also did not confirm its premalingnant nature. Seventeen LRNs did not progress to
HCC, and four of them became undetectable by various
imagings. Four new HCC lesions developed remotely from
the target LRN lesions [1].
However, we were not totally convinced of the result, as
the number of LRNs and the lengths of follow-up periods
were thought to be insufficient. Therefore, we continued
the follow-up study after the previous report was published,
and a greater number of LRNs were followed up for longer
periods than before. In addition, DNs were followed up for
comparison. We also wanted to confirm other results of the
previous study, such as the disappearance of lesions in
images and the occurrence of new HCCs remote from the
target nodules.
The results showed that we could prove the pre-malignant nature of LRNs (Figs. 2 and 3). Although the rate was
lower than that of DN, nine of 68 LRNs did show malignant transformation in the present study, quite a different
result from our former study [1]. The reason for the difference must simply be attributable to the increases in the
number of LRNs and follow-up periods. The difference in
the rates of malignant transformation between LRN and
DN is also important, highlighting the merit of classifying
non-HCC lesions in cirrhotic liver into LRNs and DNs. We
should recognize DNs as high risk lesions and LRNs as low
risk lesions.
Except for the pre-malignant nature of LRNs, other
phenomena described in our previous report were confirmed in the present study. Disappearance of nodules in
images was found in both LRNs and DNs, although the
reason for this can still not be conclusively described.
However, chronic inflammation and structural change
could be involved, with the former perhaps causing new
fibrogenesis. The newly-formed fibrous septa would then
have separated the nodules into smaller nodules. In any
event, the mechanism of disappearance still needs to be
clarified.
The occurrence of new HCC lesions remote from target
nodules was also confirmed in the present study. As
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336
discussed previously [1], the new HCC lesion is considered
to have developed from de novo-type carcinogenesis, bypassing a rather persistent stage of pre-cancerous nodules.
Understanding this phenomenon is a critical issue in daily
practical clinical activities [15]. In follow-up examinations,
the whole liver should also be carefully examined, as well
as these target nodules.
Finally, we hope the findings and considerations of this
study will prove useful for practical clinical activities in the
management of cirrhotic patients.
Acknowledgements This study (Fukuo Kondo) was supported in
part by the grants from The Vehicle Racing Commemorative
Foundation.
Compliance with ethical requirements and Conflict of interest Tsunenobu Sato, Fukuo Kondo, Masaaki Ebara, Nobuyuki
Sugiura, Shinichiro Okabe, Masahiko Sunaga, Masaharu, Yoshikawa,
Eiichiro Suzuki, Sadayuki Ogasawara, Yusuke Shinozaki, Yoshihiko
Ooka, Tetsuhiro Chiba, Fumihiko Kanai, Takashi Kishimoto, Yukio
Nakatani, Toshio Fukusato, and Osamu Yokosuka declare that they
have no conflict of interest. All procedures performed in studies involving human participants were in accordance with the ethical
standards of the institutional and/or national research committee and
with the 1964 Helsinki declaration and its later amendments or
comparable ethical standards. Informed consent was obtained from all
individual participants included in the study. This study was approved
by an ethics committee of Chiba University School of Medicine.
Open Access This article is distributed under the terms of the
Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original
author(s) and the source are credited.
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