International scientific communications in the field of colorectal tumour markers.

AIM: To analyze scientometrically the dynamic science internationalization on colorectal tumour markers as reflected in five information portals and to outline the significant journals, scientists and institutions.
METHODS: A retrospective problem-oriented search was performed in Web of Science Core Collection (WoS), MEDLINE, BIOSIS Citation Index (BIOSIS) and Scopus for 1986-2015 as well as in Dervent Innovations Index (Derwent) for 1995-2015. Several specific scientometric parameters of the publication output and citation activity were comparatively analyzed. The following scientometric parameters were analyzed: (1) annual dynamics of publications; (2) scientific institutions; (3) journals; (4) authors; (5) scientific forums; (6) patents - number of patents, names and countries of inventors, and (7) citations (number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus).
RESULTS: There is a trend towards increasing publication output on colorectal tumour markers worldwide along with high citation rates. Authors from 70 countries have published their research results in journals and conference proceedings in 21 languages. There is considerable country stratification similar to that in most systematic investigations. The information provided to end users and scientometricians varies between these data-bases in terms of most parameters due to different journal coverage, indexing systems and editorial policy. The lists of the so-called "core" journals and most productive authors in WoS, BIOSIS, MEDLINE and Scopus along with the list of the most productive authors - inventors in Derwent present a particular interest to the beginners in the field, the institutional and national science managers and the journal editorial board members. The role of the purposeful assessment of scientific forums and patents is emphasized.
CONCLUSION: Our results along with this problem-oriented collection containing the researchers' names, addresses and publications could contribute to a more effective international collaboration of the coloproctologists from smaller countries and thus improve their visibility on the world information market.

Core tip: Colorectal tumour markers represent a promising option for the early diagnosis and prognostic evaluation of colorectal cancer patients. Dynamically changing environment of the communication infrastructure in this significant interdisciplinary field deserves comprehensive scientometric assessment. By means of this specific approach, valuable and relatively objective information about the trends and perspectives of research and publication output worldwide has been provided. The results obtained and the comprehensive collection of abstracts and full texts of relevant publications on colorectal tumour markers could contribute to the further improvement of the international visibility on the world information market of coloproctologists from smaller countries.

INTRODUCTION

At present, primary colorectal cancer is diagnosed in > 1.4 million subjects annually and incidence is increasing[1]. Recently, much effort focuses on screening and earlier detection of colorectal cancer, which reduces the cancer-related mortality rate[2]. Several screening markers are currently applied to help diagnosing the early-stage colorectal cancer or even the premalignant lesions. They are divided into two different categories: stool markers, such as FOBT/FIT and blood-based markers as DNA/RNA and proteins[3]. DNA methylation-based biomarkers should be widely used to improve the current diagnosis, screening, prognosis and treatment prediction in colorectal cancer[4]. Detection of epigenetic and genetic alterations of circulating cell-free DNA as DNA methylation or DNA mutations and related ribonucleic acids improves cancer detection based on unique, colorectal cancer-specific patterns which serve as biomarkers in screening and diagnosis[5].

The analysis of a panel of 92 candidate cancer protein markers measured in 35 clinically identified colorectal cancer patients and 35 ones identified at screening colonoscopy proves the importance of the validation of the early detection markers in a true screening setting for limiting the number of false-positive findings[6]. Serum expression levels of miR-17, miR-21, and miR-92 represent valuable markers for recurrence after adjuvant chemotherapy in colon cancer patients[7].

A plasma-based protein marker panel for colorectal cancer detection was identified by multiplex targeted mass spectrometry using multiple reaction monitoring technology[8]. The usefulness of diagnostic marker panels was already suggested by us, too[9]. The measurement of metabolite porphyrin concentrations in urine could serve as a new screening and recurrence marker for colorectal cancer[10]. Better understanding and elucidation of the various influences provides a more accurate picture of the segmental distribution of some common molecular markers in colorectal cancer such as KRAS, EGFR, Ki-67, Bcl-2, and COX-2, potentially allowing the application of a novel patient’s stratification for treatment based on particular molecular profiles in combination with tumour location[11].

The main objectives of this article were to comparatively analyze by means of scientometric methods the dynamic science internationalization in the actual topic of colorectal tumour markers as reflected in five information portals (data-bases), to outline the most significant primary information sources, scientists and institutions in this interdisciplinary field and thus attempt at contributing to the further improvement of the international scientific communications in smaller countries.

MATERIALS AND METHODS

In July 2016, a retrospective problem-oriented search on this topic using the term of “colorectal marker(s)” in publication titles only was performed. Information retrieval covered the following information portals (data-bases): Web of Science Core Collection (WoS), MEDLINE and BIOSIS Citation Index (BIOSIS) (Thomson Reuters, Philadelphia, PA, United States) as well as Scopus (Elsevier, the Netherlands) for the period from January 1st, 1986 till December 31st, 2015. Information about patents indexed in Dervent Innovations Index (Derwent) (Thomson Reuters, Philadelphia, PA, United States) between 1995 and 2015 was analyzed, too.

The following scientometric parameters were analyzed: (1) annual dynamics of publications - total number and thematic belonging of abstracted publications as well as languages and types of primary publications; (2) scientific institutions - number of abstracted publications and country belonging; (3) journals - total number and number of abstracted articles from single journals as well as narrow-profile specialized journals containing the term of “(bio)marker(s)” in their titles; (4) authors - number of unique names and number of publications; (5) scientific forums - titles and publications in them; and (6) patents - number of patents, names and countries of inventors and assignees as well number of claims in single patents, and (7) citations - number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus. Purposeful combinations of such quantitative parameters enabled a comprehensive assessment of the unity of the institutionalization, interdisciplinarity and internationalization of modern science in this narrow field of rising socio-medical importance[12].

RESULTS

Our results revealed several essential peculiarities of the dynamic structure of the publication and citation output on this topic during these three decades.

The amounts of relevant papers, journals containing them, and countries of authors varies between the data-bases (Table 1). There are 106 patents indexed in Derwent during the period of the observation

Table 1

General bibliometric characteristics of four data-bases concerning the topic

Parameter	WoS	BIOSIS	MEDLINE	Scopus
Total number of publications	1587	1172	1108	1221
Total number of journals	334	265	364	N/A
Total number of journals with one article only	163	140	201	N/A
Total number of languages (n = 21)	5	11	17	19
Total number of countries of authors (n = 70)	63	55	N/A	63
Total number of research areas (WoS categories)	48	42	49	21

N/A: Not available.

The annual dynamics of the number of publications on this topic which have been abstracted in WoS, BIOSIS, MEDLINE and Scopus and that of the patents abstracted in Derwent are illustrated on Figures 1 and 2. There is a considerable recent increase of the publication output, especially in WoS.

Figure 1

Annual dynamics of the number of publications on the topic abstracted in four data-bases.

Figure 2

Annual dynamics of patents on the topic.

The distribution of some leading countries according to the number of publications in WoS, BIOSIS, and Scopus indicates a considerable stratification typical of most scientometric investigations (Figure 3). The corresponding figures for the United States are 314, 228, and 223 publications; for Canada - 36, 17, and 21; for Switzerland - 34, 21, and 20; for Poland - 17, 13, and 24; for Bulgaria - only five, three, and three, respectively, etc. Meanwhile, the aforementioned paper of ours[8] has received six citations in WoS.

Figure 3

Country distribution according to the number of publications on the topic abstracted in three data-bases.

The distributions of document types (Table 2) and languages (Table 3) display an obvious variability between these four data-bases. This is mainly due to the strict restrictions of journal coverages permanently applied by the editors of WoS.

Table 2

Document type distribution in four data-bases

Document type	WoS	BIOSIS	MEDLINE	Scopus
Journal article	870	700	1057	970
Review	63	38	118	114
Congress proceedings	57	6	1	39
Meeting abstract	543	313	0	0
Editorial	34	6	17	18
Letter-to-the-editor	37	9	28	32
Book chapter	6	9	0	8
Evaluation study	0	0	28	0
Multicenter study	0	0	19	0
Randomized controlled trial	0	0	15	0
Meta-analysis	0	0	13	0
Validation study	0	0	11	0
Patent	0	19	0	0

Table 3

Language distribution of publications on the topic abstracted in four data-bases

Language	WoS	BIOSIS	MEDLINE	Scopus
English	1545	1136	1017	1095
German	17	5	10	17
French	14	9	12	14
Spanish	9	2	9	12
Japanese	0	7	17	21
Chinese	0	6	11	27
Italian	2	1	6	7
Polish	0	0	5	7
Czech	0	1	4	5
Danish	0	0	4	4
Other (11)	0	3 (5)	7 (15)	9 (15)

The lists of the so-called “core” journals containing the greatest number of relevant papers on the topic (Table 4) and the most productive authors in WoS, BIOSIS, MEDLINE and Scopus (Table 5) along with the list of the most productive authors - inventors in Derwent (Table 6) represent a particular interest not only to the beginners in the field but also to the institutional and national science managers and the journal editorial board members as well. It should be added that among the top 20 journals, there are two titles equally represented in four data-bases, three titles are omitted in one data-base but one title, Lab Invest is omitted in both MEDLINE and Scopus. On the other hand, most journals in the scientometric “tail”, i.e., presenting with one article abstracted only, are almost equally indexed in these four data-bases thus confirming Bradford’s law of journal scattering in any research field. In this case, these journals amount to 48.80% in WoS, to 52.83% in BIOSIS, and to 55.22% in MEDLINE (their absolute counts are shown in Table 1).

Table 4

“Core” journals on the topic in four data-bases

Rank	Journal title	WoS	BIOSIS	MEDLINE	Scopus
1	Gastroenterology	115	100	15	15
2	J Clin Oncol	96	4	12	13
3	Br J Cancer	52	47	45	47
4	Anticancer Res	46	54	39	39
5	Cancer Res	43	45	14	14
6	Eur J Cancer	38	36	20	20
7	Clin Cancer Res	36	9	34	34
8	Dis Colon Rectum	33	4	24	19
9	Oncol Rep	28	28	28	28
10	Int J Cancer	27	25	26	26
Total "core" journals - n (%)		10 (2.99)	10 (3.76)	10 (2.75)	10 (N/A)
Total publications - n (%)		514 (32.39)	352 (30.03)	255 (23.01)	257 (21.05)

N/A: Not available.

Table 5

Most productive authors on the topic in four data-bases

Rank	Author’s name	WoS	BIOSIS	MEDLINE	Scopus
1	Ahlquist DA	25	31	10	8
2	Mori M	22	14	16	20
3	Doki Y	17	11	13	16
4	Nielsen HJ	17	12	2	11
5	Lugli A	16	14	5	6
6	Mimori K	16	10	11	14
7	Zlobec I	16	14	5	6
8	Inoue Y	14	4	10	10
9	Ishi H	14	8	11	14
10	Mahoney DW	14	11	1	2

Table 6

Most productive authors - inventors on the topic in Derwent

Name	Country	City	Institution	Patents
Karl J	Germany	Penzberg	Roche Diagnostic GmbH	9
Choquet- Kastylevsky G	France	Nancy Letoile	Biomerieux SA	9
Charrier JP	France	Nancy Letoile	Biomerieux SA	9
Ataman-Oenal Y	France	Nancy Letoile	Biomerieux SA	6
Beaulieu C	France	Nancy Letoile	Biomerieux SA	6
Ahlquist DA	United States	Rochester	Mayo Clinic	4

Only a small number of most productive scientific institutions in WoS and Scopus (Table 7) and institutions - assignees in Derwent (Table 8) is provided in order to indicate their undoubtedly high relative share on the world information market.

Table 7

Most productive institutions on the topic in WoS and in Scopus

Rank	Institution	WoS	Scopus
1	German Cancer Research Center	29	26
2	Mayo Clinic	29	17
3	Harvard University	28	14
4	Osaka University	25	25
5	Kyushu University	22	22
6	Universität Heidelberg	25	19
7	Ludwig-Maximilians-Universität München	21	23
8	Memorial Sloan-Kettering Cancer Center	20	12
9	Kaohsiung Medical University	15	22
10	University of Copenhagen	23	9

Table 8

Most productive institutions - assignees on this topic in Derwent

Nomination	Country	Patents
Biomerieux SA	France	9
Hoffmann La Roche	Switzerland	9
Mayo Medical Education and Research	United States	4
Ruiqu Biotechnology Shanghai Co. Ltd	China	3
Signature Diagnostics GmbH	Germany	3
Shimadzu Corporation	Japan	3
Ver Christelijk Wetenschappel Onderw	The Netherlands	3
Fudan University	China	3

The computerized analysis published online by Thomson Reuters of the main research areas (in BIOSIS and MEDLINE) and of the Web of Science categories (in WoS itself) has identified significant differences concerning several indexing results between there three data-bases, Table 9). We would like only to mention the figures for “gastroenterology and hepatology”, “biochemistry and molecular biology”, and “immunology” and to emphasize the achievements in these interdisciplinary fields in clinical medicine and biomedicine.

Table 9

Dominant research areas (WoS categories) on the topic in three data-bases

Rank	Research area (WoS category)	WoS	BIOSIS	MEDLINE
1	Oncology	834	1153	1034
2	Gastroenterology and hepatology	297	1084	166
3	Surgery	301	55	132
4	Pathology	169	55	74
5	Cell biology	47	42	231
6	Biochemistry and molecular biology	42	266	703
7	Medical laboratory technology	33	393	48
8	Pharmacology and pharmacy	27	144	190
9	Radiology, nuclear medicine and medical imaging	25	15	30
10	Genetics and heredity	24	402	490
11	Public, environmental and occupational health	23	22	29
12	Immunology	10	77	454
13	Hematology	7	22	43
14	Nutrition and dietetics	5	16	17
15	Endocrinology and metabolism	3	98	22

The distributions of the number of authors according to the number of their patents (Figure 4) and that of the declared claims in their patents (Figure 5) demonstrate a significant research activity on the topic of colorectal tumour markers. This specific scientometric evaluation contributes to the identification of the players at the fore-front of clinical medicine-related technological progress.

Figure 4

Distribution of the number of authors according to the number of their patents on the topic.

Figure 5

Distribution of the number of declared claims in the patents on the topic.

Several common citation patterns on this topic as reflected in WoS and BIOSIS are listed in Table 10. The percentages of the times cited without self-citations and of the citing articles without self-citations are extraordinarily high, indeed. The so-called “h-index” introduced by Hirsch[13] is very high - 75 and 57 in WoS and in BIOSIS, respectively.

Table 10

Cumulative citation patterns on the topic in WoS and BIOSIS

Citation parameter	WoS	BIOSIS
Total number of publications	1587	1172
Sum of the times cited	25116	13297
Sum of the times cited without self-citations	24092	12777
Percentage of these times cited	95.92	96.09
Citing articles	19607	11061
Citing articles without self-citations	19120	10779
Percentage of these citing articles	97.52	97.45
Average citations per item	15.83	11.35
Average citations per year	810.19	443.23
Articles cited at least once	961	643
Percentage of these articles	60.55	54.86
H-index	75	57

The comparative assessment of ten articles which have been most cited in WoS, in BIOSIS, and in Scopus (Table 11)[14-23] identifies two weird discrepancies. The article published in the “core” journal J Clin Oncol[17] has not been indexed in Scopus at all (as opposed to the other 13 articles in this journal) as well as the article co-authored by Sturgeon et al[22] and published in the journal Clin Chem has not been indexed in BIOSIS at all (as opposed to the other nine articles in this journal ranked 15th among a total of 265 journals).

Table 11

Ten most cited articles on the topic in three data-bases

Ref.	Journal title, volume, year and pages	WoS	BIOSIS	Scopus
Ng et al[14]	Gut 2009; 58: 1375-1381	593	447	656
Bast et al[15]	J Clin Oncol 2001; 19: 1865-1878	552	314	670
Cui et al[16]	Science 2003; 299: 1753-1755	472	400	530
No author list[17]	J Clin Oncol 1996; 14: 2843-2877	388	234	Absent
Walther et al[18]	Nat Rev Cancer 2009; 9: 489-499	315	243	348
Duffy[19]	Clin Chem 2001; 47: 624-630	253	141	289
Duffy et al[20]	Eur J Cancer 2007; 43: 1348-1360	245	160	276
Nakamori et al[21]	Gastroenterology 1994; 106: 353-361	234	179	219
Sturgeon et al[22]	Clin Chem 2008; 54: E11-E79	211	Absent	255
Duffy et al[23]	Eur J Cancer 2003; 39: 718-727	202	120	235

The comprehensive scientometric analysis of the bibliographic information about the congresses, symposia, meetings, and conferences held in many countries which proceedings have been abstracted in WoS and in BIOSIS clearly outlines the rising role of these forums for the intensive development of the international scientific communications and science advancement as well (Tables 12 and 13).

Table 12

Bibliometric characteristics of scientific forums on the topic in WoS and BIOSIS

Parameter	WoS	BIOSIS
Number of forum titles	95	73
Number of unique forums	170	203
Number of publications	377	432
Number of forums with a single event only	71	52
Number of forums with two events	9	5
Number of forums with three events	5	2
Number of forums with one publication only	57	117
Number of forums with two publications	10	34
Number of forums with three publications	5	16
Maximal number of events of a unique forum	12	27
Maximal number of publications in a unique forum	58	102

Table 13

Scientific forums with most events and papers in them on the topic in WoS and BIOSIS

Scientific forum title	WoS		BIOSIS
	Events	Papers	Events	Papers
Digestive Disease Week	12	58	25	90
Annual Meeting of the American Association for Cancer Research	4	17	27	102
Annual Meeting of the United States and Canadian Academy of Pathology	10	34	11	29
Annual Meeting of the American Society of Clinical Oncology	8	49	0	0
European Society for Medical Oncology Congress	7	17	1	5
World Congress of Gastrointestinal Cancer	7	24	0	0
Meeting of the International Society for Oncodevelopmental Biology and Medicine	3	6	9	16
Meeting of the Pathological Society of Great Britain and Ireland	5	5	11	11
European Congress of Pathology	0	0	11	22
Annual Meeting of the American College of Gastroenterology	4	5	5	6

In WoS and in BIOSIS, we have identified six scientific forums containing the terms of “tumour or cancer (bio) markers” in their titles (Table 14) and, in four data-bases, we have found out eight specialized journals meeting this criterion (Table 15). The annual dynamics of these 51 articles is characterized by two peak values (in 2010 and in 2014) (Figure 6). The considerable relative share (78.43%) of the papers published in foreign specialized journals stresses, indeed (Figure 7) and testifies to the substantial role of this particular aspect of science internationalization.

Table 14

Scientific forums with “tumour or cancer (bio)markers” in their titles in WoS and BIOSIS

Scientific forum title	WoS		BIOSIS
	Events	Papers	Events	Papers
Hamburg Symposium on Tumor Markers	2	3	5	8
Congress (Meeting) of the International Society of Oncology and Biomarkers	3	4	2	2
Annual Meeting of the EORTC/NCI/ASCO on Molecular Markers in Cancer	1	2	1	2
Annual Conference on Diet and Cancer: Markers, Prevention, and Treatment	1	1	0	0
International Symposium on Tumor Markers - From Biology to Therapy	1	1	0	0
Joint Meeting on Markers in Cancer of ASCO, EORTC and NCI	0	0	1	1

Table 15

Specialized journals with the term of “(bio)markers” in their titles in four data-bases

Rank	Journal title	WoS	Scopus	MEDLINE	BIOSIS	Total
1	Cancer Epidemiol Biomarkers Prev	0	0	0	15	15
2	Int J Biol Markers	5	0	11	9	131
3	Cancer Biomarkers	7	8	7	8	81
4	Disease Markers	5	5	5	5	51
5	J Tumor Marker Oncol	0	3	0	6	61
6	Biomarkers	2	0	2	2	21
7	Biomarkers Med	0	0	1	0	1
8	Genet Testing Mol Biomarkers	1	0	1	0	11
Total number of publications		20	16	27	45	511
Total number of journals		5	3	6	6	81
Countries of authors		19	13	20	20	251
Countries of journals		5	2	4	5	51
Articles in domestic journals		2	1	2	14	111
Articles in journals published abroad		18	15	25	31	401

The sum of unique items is smaller than the total amount of single items due their duplication in several data-bases.

Figure 6

Annual dynamics of papers on the topic in specialized journals.

Figure 7

Papers on the topic published in domestic and foreign specialized journals. I: Cancer Epidemiol Biomarkers Prev; II: Int J Biol Markers; III: Cancer Biomarkers; IV: Disease Markers; V: J Tumor Marker Oncol; VI: Biomarkers; VII: Biomarkers Med; VIII: Genet Testing Mol Biomarkers.

DISCUSSION

Our results convincingly outline the rising publication output on colorectal tumour markers worldwide and the significant citation activity as substantial features of quality and international prestige under the conditions of science globalization.

Modern colorectal tumour markers are used either for diagnostic, or for prognostic purposes. In addition, they could be applied for therapeutic evaluations.

The combined detection of two tumour markers, serum p53 antibody and carcinoembryonic antigen (CEA), improves the diagnostic sensitivity and prognosis of early-stage colorectal cancer patients[24].

A diagnosis strategy of serum tumour markers, an artificial intelligent algorithm, provides decision support for physicians on the usage of different tumour markers and diagnosis of colorectal cancer[25].

CEA containing macrophages combined with C-reactive protein possesses diagnostic potential in early colorectal cancer[26]. The diagnostic models based on the logistic regression analysis, support vector machine and back-propagation neural network demonstrate a higher early diagnostic value of the combination of serum tumour markers, e.g., CEA, cancer antigen (CA) such as CA 19-9, CA 242, CA 125, and CA 15-3 for colorectal cancer[27]. SATB2 protein is a diagnostic marker for tumours of colorectal origin and provides a new and advantageous supplement for clinical differential diagnostics[28]. In combination with CK7 and CK20, its specificity increases from 77% up to 100%. The most common markers for such tumours include the expression of CK20, often along with lack of CK7, i.e., the CK20+/CK7- phenotype[28].

MYBL2 gene is an independent prognostic marker with tumour-promoting functions in colorectal cancer and its overexpression may play an important role in tumourigenesis[29]. HLA class II antigen expression in colorectal cancer is a reliable prognostic marker as it is related with a favourable clinical course of the disease[30]. The combined high levels of some inflammatory cytokines such as CXCL8, vascular endothelial growth factor and Pentraxin3 are potential prognostic markers as they are associated with increased risk of colorectal cancer recurrence independently of TNM staging and with worse survival[31]. The circulating microRNAs markers miR-122 and miR-200 family members could be used in the development of a multi-marker blood test for colorectal cancer prognosis and survival[32]. The decreased erythropoietin expression, high vascular endothelial growth factor levels and elevated cyclin B1 expression, predominant moderate tumour differentiation, absence of metastasis, and negative lymph node status are reliable proliferation and differentiation markers indicating the low level of aggressiveness, better prognosis, and longer colorectal adenocarcinoma patient’s survival[33]. By means of solid-phase proximity ligation assay, 35 protein markers were simultaneously analyzed in a small amount of blood of stage I to IV colorectal cancer patients, however, these markers did not give better prognostic information than CEA[34].

An outlined correlation exists between the differentiation degree and expression of aldehyde dehydrogenase 1, a stem cell marker, in colorectal carcinoma cells[35]. Low-stage tumours exhibit a higher expression of aldehyde dehydrogenase 1 or CD133 compared with high-stage tumours while CD133 expression is associated with lymph node metastasis-positive cases thus predicting the disease prognosis. Aldehyde dehydragenase 1 and Nodal are important prognostic markers in colorectal cancer as there is a significant correlation between their expression and the differentiation degree, metastasis, number of tumour-positive lymph nodes and disease stage[36].

Science internationalization includes not only direct research interaction between single scientists from different countries and their teams organized through official contracts or within informal collectives but also several essential components[12]: (1) continuous creation of new international scientific societies and international associations of national societies, of new international scientific journals and international publishers or publishing houses; (2) publishing of scientific papers, reviews and book reviews in foreign journals and periodicals; (3) translation and publishing of monographs by foreign authors; (4) organization of international scientific forums and participation in them of authors from numerous foreign countries; (5) enrichment of the forms of immediate exchange of scientists from other countries; (6) unlimited dissemination of new scientific information through modern information-communication technologies; (7) modernization and automatization of scientific libraries; and (8) introduction of electronic journals and monographs; and (9) overcoming of the traditional barriers for interpersonal communication between scientists from different countries.

Similarly to other authors[37], we face not only advantages but also disadvantages in the comprehensive activity of both editors and staff in these two widely recognized information centres in the United States and in the Netherlands. There is user-friendly uninterrupted online access to the information portals providing a rising amount of full-text articles. The computerized data processing facilitates automated problem-oriented information retrievals and large-scale scientometric analyses as well. However, several unfavorable features deserve a special attention. Some author’s affiliations are incomplete, even within one and the same scientific institution. Single significant publications are missing in at least one of these four data-bases although the corresponding journals are covered. The incorporation of proceedings from congresses, conferences and symposia is insufficient. The indexing of primary document types and research areas should be further improved, too.

There is a stable research interests in the issues of a variety of peculiarities of the modern international scientific communications and collaboration worldwide.

Publication coverage in Scopus or WoS, English as a specific international language, and journal articles as a specific type of publication, are indicators of research quality and internationalization in the social sciences and humanities[38]. There is a different extent of internationalization of peer reviewed and non-peer reviewed book publications in the social sciences and humanities in Belgium[39].

The analysis of the dynamics of journal internationality using using 1398 journals and 2557229 papers during 1991-2014 demonstrates that journals’ papers and references have become more globalized over time[40]. For both national and multinational publishers, most of the changes in journal internationalization occur between the fourth and sixth year of indexing in WoS. Natural sciences as well as engineering and technology have the most international papers but the journals in medical and health sciences, natural sciences, and agricultural sciences contain the most international references.

Тhe emergence of a new transnational demand in health research dealing with global regenerative medicine and parallel markets is analyzed according to relevant theoretical dilemmas in medical anthropology and the sociology of science and health[41].

The investigation of the international and domestic coauthorship relations of all citable items in the Social Sciences Citation Index 2011 demonstrates that the international networks in the social sciences have grown during the last decades in addition to the national ones but not by replacing them[42]. The comparison of the internationalization of more than one thousand academic journals in six fields of science indicates that social sciences literature is still nationally and linguistically fragmented more than natural sciences one[43].

A standardization method that transforms all fractions of internationally coauthored papers from a dataset of the National Science Foundation into a comparable framework is applied to examine the evolution and convergence of the patterns of international scientific collaboration between 1973 and 2012[44]. The convergence of these long-run collaboration patterns between the applied and basic sciences might be a contributing factor that supports the evolution of modern scientific fields.

The promises and challenges of international collaboration in achieving success towards poverty, environment, education, science, and medicine are reviewed comprehensively[45]. A model for sustainable university-based international plastic surgery collaboration between plastic surgery consultants from abroad and a hospital in a developing country is implemented[46]. The analysis of China’s international publications on healthcare science and services research identifies a rapid recent increase[47]. Collaboration among countries, institutions and authors increase, too. The academic impact of publications with partners from European and American countries is relatively higher than of those with partners from Asia. The most prominent actors are Peking University, Fudan University, Chinese University of Hong Kong, and University of Hong Kong. The significance of the international scientific collaboration in the field of minimally invasive general surgery is highlighted[48].

The bibliometric analysis of Cuban scientific publications listed in PubMed during the period between 1990 and 2010 proves that Cuban science policy and practice ensure the application of science for social needs by harnessing human resources through national and international collaboration, building stronger scientific capacity[49]. The research output and impact of 479 Mexican researchers working abroad and included in the Mexican National System of Researchers are investigated in terms of production, mobility and scientific collaboration[50]. Mobility exerts a strong effect on scientists’ international collaboration.

The dynamic internationalization of modern science is analyzed by Bulgarian authors in different interdisciplinary fields such as haemorrhagic stroke prevention[51], paediatric sleep apnea[52], applications of the geographical information systems in health planning[37], etc.

In conclusion, contemporary colorectal tumour markers are more and more widely studied and routinely applied in clinical coloproctology worldwide thus promoting the further improvement of individualized patient’s management. We have revealed a series of discrepancies in the coverage and computerized processing of the recent scientific literature on colorectal tumour markers by these powerful information centres that necessitates refinements in their editorial policy. The creation of this comprehensive problem-oriented collection with purposefully systematized files containing the researchers’ names, addresses and publications is designed mainly for specialists in coloproctology from smaller countries who strive for a more effective collaboration with colleagues from eminent centres abroad and, in this way, to achieve an improved international visibility on the world information market.

COMMENTS

Background

A summary of the increasing role of screening and early detection of colorectal cancer with a variety of specific colorectal serum markers that is reflected in five modern information portals covering world literature on this hot topic during the recent decades.

Research frontiers

Nowadays, science stratification in terms of individual researchers, teams, institutions, journals, and countries deserves a special attention to be paid by the comprehensive scientometric approach to the structure and dynamics of international scientific communications in the field of colorectal tumour markers. Such a particular analysis is capable of identifying the most productive authors representing a true interest to the beginners in oncological coloproctology and related fields, the institutional and national science managers and the journal editorial board members. By providing systematized factual information to end users, the scientometric results outline the emerging opportunities for fruitful interdisciplinary and international collaboration.

Innovations and breakthroughs

Under the conditions of enormous globalization and competition in contemporary science, timely orientation in and awareness of the promising advances in colorectal tumour markers can substantially contribute to new scientific achievements not only by leaders working in powerful countries but also by the scientists from the rest of the world. Thus the collaboration trends can be further empowered and expanded.

Applications

In the era of telecommunication technologies, the new scientific information on colorectal tumour markers published in the ocean of journals, conference proceedings, monographs, patents and other primary literature sources is very easy to access in case one could be trained in information science and applied scientometrics. Besides science policy managers at different levels and journal editors could successfully apply these scientometric results, too.

Terminology

At the first glance, the particular terminology used in this article looks nearly strange to gastrointestinal surgeons, coloproctologists, and oncologists. On the other hand, there is a rising amount of meta-analyses, systematic reviews and scientometric papers on different topics recently published in various journals. All these publications make specific contributions to the uninterrupted world science advancement of benefit to patients.

Peer-review

The authors explored five information portals for the topic of colorectal tumour markers and outlined the significant journals, scientists and institutions. The authors made tremendous efforts on searching and comparing the five information portals, and showed the detailed results. This paper is interesting.