Inflammation Markers in Ovarian Cancer: What 24 Years of Research Reveals

Table of Contents

• Key Points
• Why This Research Matters: Inflammation and Ovarian Cancer
• Study Methods: How the Research Map Was Built
• Key Finding 1: A Rising Wave of Publications
• Key Finding 2: Global Contributions by Country
• Key Finding 3: Leading Research Institutions
• Key Finding 4: Influential Authors
• Key Finding 5: Key Journals and Their Citation Networks
• Key Finding 6: The Most Influential Studies
• Key Finding 7: Research Hotspots and Shifting Themes
• Clinical Implications: What These Findings Mean for Patients
• Limitations: What This Study Could Not Show
• Recommendations for Patients
• Frequently Asked Questions
• Source Information

Key Points

• Analysis of 595 articles from 2000–2024 shows rising research on inflammation markers in ovarian cancer.
• US and China produced nearly half of all research; Harvard University was the most productive institution.
• Inflammatory markers such as CRP, IL-6, NLR, and PLR are being studied for diagnosis and prognosis.
• Recent research focuses on biomarkers, prognosis, and immunotherapy, signaling future directions.
• Study limitations include relying only on Web of Science and English-language articles through October 2024.

Why This Research Matters: Inflammation and Ovarian Cancer

Ovarian cancer is a malignant tumor (cancer) of the female reproductive system. It usually begins in the epithelial cells, which are the cells lining the surface of the ovary. According to the Global Cancer Observatory (GLOBOCAN), ovarian cancer is one of the leading causes of cancer-related death among women worldwide. Its frequency varies greatly across different regions and populations.

Doctors have long noticed that chronic inflammation — a long-lasting inflammatory response in the body — is linked to many diseases, including cancer. A classic example is stomach cancer, which is strongly associated with chronic inflammation caused by long-term Helicobacter pylori infection.

Inflammation can drive cancer in several ways. Inflammatory cells release reactive oxygen species (ROS, unstable molecules that can damage cells) and cytokines (cell-signaling proteins). These substances can damage DNA, activate oncogenes (genes that promote cancer) and suppress tumor suppressor genes (genes that normally keep cancer in check). The result is that tumor cells grow, survive, migrate, and invade healthy tissue more easily.

For ovarian cancer specifically, inflammation markers in the blood are attracting intense research interest. Some studies show that high levels of C-reactive protein (CRP, a protein the liver makes in response to inflammation) and other inflammatory cytokines are linked to a higher risk of developing ovarian cancer. Blood-based markers such as the neutrophil-to-lymphocyte ratio (NLR, the balance between two types of white blood cells) and the platelet-to-lymphocyte ratio (PLR, the balance between clotting cells and white blood cells) are also being studied as possible prognostic indicators (clues about how a patient's disease may progress).

This matters because ovarian cancer is notoriously difficult to catch early. It has complex biological features and is highly heterogeneous, meaning it varies greatly from patient to patient. Standard treatment usually combines surgery, chemotherapy, and targeted therapy. The standard chemotherapy regimen typically uses platinum-based drugs such as carboplatin plus paclitaxel for six cycles. Ovarian cancer's overall prognosis remains poor.

Some patients with platinum-sensitive recurrent ovarian cancer (cancer that returns and still responds to platinum drugs) may be offered secondary cytoreductive surgery, non-platinum chemotherapy, or anti-angiogenic drugs (medicines that starve tumors by blocking new blood vessel growth). Finding reliable biomarkers (biological clues measurable in blood or tissue) to support early diagnosis and predict outcomes has therefore become a global research priority. This study set out to map the entire research landscape on this topic using bibliometric methods, which use statistics and visual maps to analyze large bodies of published literature.

Study Methods: How the Research Map Was Built

The researchers searched the Web of Science Core Collection (WoSCC), a major scientific database, for relevant papers published between January 1, 2000, and October 31, 2024. Their search combined the terms "inflammatory indicators and ovarian cancer" and "inflammatory indicator metabolism and ovarian cancer," limited to English-language articles and review articles. Two independent researchers (LY Zhang and LL Guo) screened every manuscript to confirm it fit the study topic. The experienced corresponding author (HY Wang) resolved any disagreements.

The initial search identified 595 relevant studies for analysis. For each publication, the team collected the publication year, title, author names, institutions, countries or regions, abstract, keywords, and the publishing journal's name.

To analyze the data, the researchers used several specialized software tools:

• VOSviewer (versions 1.6.18 and 1.6.20): software that builds maps of collaboration networks, co-citation patterns, and keyword co-occurrence. In these maps, each circle (node) represents an item such as a country, institution, journal, or author; the node's size shows how much that item published, and its color shows its category.
• CiteSpace (versions 6.1.R1 and 6.3.R1): software developed by Professor Chen C that was used to create dual-map overlays of journals and to analyze citation bursts (sudden surges in how often a paper is cited).
• R package "bibliometrix" / Biblioshiny (version 3.2.1): used for thematic evolution analysis and for building a network showing the global distribution of publications.
• Microsoft Office Excel 2019: used for quantitative analysis of publication counts.

Journal quartiles and impact factors were taken from the Journal Citation Reports 2020. The analysis moved from a broad overview to specific detail, covering countries and regions, institutions, authors, journal distribution, key documents and references, keywords, and research trends over time.

Key Finding 1: A Rising Wave of Publications

Research on inflammation markers in ovarian cancer has grown dramatically over the past two decades. Only 4 articles were published on this topic in 2000. By 2024, that number had climbed to 42 articles in just that year alone. The highest annual output came in 2023, with 62 articles published in a single year. Overall, the 24-year period produced 595 studies, and the growth trend shows no sign of slowing.

This upward pattern tells a clear story. Scientists are dedicating more attention to how inflammation-related markers could help with earlier detection and better prediction of outcomes. The steady rise, with a recent peak, suggests that this field is still expanding and evolving.

Key Finding 2: Global Contributions by Country

Researchers from 1,543 institutions in 58 countries contributed to the 595 studies. Scholars from all over the world are engaged in this research area. However, a few countries dominate the field.

The United States ranked first, while China ranked second. Together, the top 20 countries' output made up a large share of all publications. The table below lists the 20 most productive countries and regions, with their total articles and total citations received.

In the table, SCP stands for single-country publications (papers written by authors from one country alone) and MCP stands for multiple-country publications (papers involving international collaboration). Total citations (TC) count how many times a country's papers were cited by others. Average citations (AC) is the mean number of citations per paper.

1. United States: 133 articles (22.4%), 7,366 total citations, average 55.4 citations per paper
2. China: 118 articles (19.8%), 2,816 total citations, average 23.9 citations per paper
3. Italy: 35 articles (5.9%), 1,216 total citations, average 34.7 citations per paper
4. Japan: 25 articles (4.2%), 551 total citations, average 22.0 citations per paper
5. United Kingdom: 22 articles (3.7%), 1,596 total citations, average 72.5 citations per paper
6. Turkey: 21 articles (3.5%), 427 total citations, average 20.3 citations per paper
7. South Korea: 19 articles (3.2%), 717 total citations, average 37.7 citations per paper
8. Germany: 18 articles (3.0%), 708 total citations, average 39.3 citations per paper
9. Australia: 17 articles (2.9%), 1,139 total citations, average 67.0 citations per paper
10. India: 16 articles (2.7%), 250 total citations, average 15.6 citations per paper
11. Poland: 16 articles (2.7%), 330 total citations, average 20.6 citations per paper
12. Egypt: 12 articles (2.0%), 172 total citations, average 14.3 citations per paper
13. France: 10 articles (1.7%), 1,227 total citations, average 122.7 citations per paper
14. Greece: 10 articles (1.7%), 370 total citations, average 37.0 citations per paper
15. Iran: 10 articles (1.7%), 111 total citations, average 11.1 citations per paper
16. Canada: 9 articles (1.5%), 809 total citations, average 89.9 citations per paper
17. Romania: 8 articles (1.3%), 44 total citations, average 5.5 citations per paper
18. Austria: 7 articles (1.2%), 214 total citations, average 30.6 citations per paper
19. Brazil: 6 articles (1.0%), 98 total citations, average 16.3 citations per paper
20. Finland: 6 articles (1.0%), 180 total citations, average 30.0 citations per paper

Collaboration patterns also stand out. The United Kingdom had a very high international collaboration rate, with 59.1% of its papers involving multiple countries. Canada's rate was even higher at 77.8%, and Finland's reached 66.7%. By contrast, Turkey and Egypt published entirely within their own borders, with 0% international collaboration. The United States is the country that most often initiates and participates in international cooperation, followed by China.

It is worth noting that US publications were cited far more often overall (7,366 total citations) than Chinese publications (2,816), and the average citation rate per paper was more than twice as high for US research. Citation counts are a rough measure of how influential research has been within the scientific community.

Key Finding 3: Leading Research Institutions

Among all universities and research centers worldwide, 10 of the top 15 most productive institutions are based in the United States, and 2 are based in Germany. The leading institution stands out clearly from the rest.

Harvard University in the United States published about 100 papers, giving it the top position by a wide margin. Two US government research bodies tied for second place, each publishing 52 papers:

• The National Institutes of Health (NIH, the US government's medical research agency)
• The NIH National Cancer Institute (NCI, the US government's cancer research agency)

The other institutions in the top tier include the Egyptian Knowledge Bank (Egypt, 41 articles), the University of Texas System (USA, 35 articles), the University of Toronto (Canada, 34 articles), the University System of Ohio (USA, 33 articles), and the German Cancer Research Center (DKFZ, Germany, 30 articles). Harvard showed the sharpest rise in publication output over time. Network maps confirmed that Harvard, the NIH, and the NCI are central hubs in this research community, and their collaborative connections grew especially fast between 2014 and 2024.

Key Finding 4: Influential Authors

Individual researchers were ranked in two ways: by their H-index (a measure that combines how many papers an author published with how often those papers were cited) and by total citations received.

Author WENTZENSEN N had the highest H-index, followed by TRABERT B. When ranked by total citations, CHATURVEDI AK ranked first with 683 total citations. HILDESHEIM A ranked second with 651 total citations. These high citation totals highlight their significant influence on the field.

Collaboration network maps showed that WENTZENSEN N and TRABERT B published the largest number of papers, shown by their large nodes in the network. These two authors also emerged as central figures in the collaboration networks between 2014 and 2020. When measuring locally cited authors, HILDESHEIM A ranked first, followed by TRABERT B.

Key Finding 5: Key Journals and Their Citation Networks

Scientific journals act as the meeting points for research. The study collected the 15 journals that published the most articles on inflammation markers and ovarian cancer. Several journals stand out as major homes for this research.

Cancer Epidemiology, Biomarkers & Prevention and the Journal of Ovarian Research published the most articles on this topic. They were followed by Cancer and PLOS ONE. These four journals are central outlets where patients and researchers can expect to find new findings in this area.

Citation analysis adds another layer of insight. Cancer Research (CANCER RES) was cited 766 times by articles in this field, ranking first. Gynecologic Oncology (GYNECOL ONCOL) was cited 636 times, ranking second. A dual-map overlay of journals showed how citing journals and cited journals relate to one another. Network diagrams also revealed positive co-citation relationships among Cancer Epidemiology Biomarkers & Prevention, the Journal of Ovarian Research, Cancers, and PLOS ONE — meaning these journals are frequently cited together in the same papers.

Key Finding 6: The Most Influential Studies

Some scientific papers become "classics" that later research builds upon. The study measured this through local citations, meaning how often a reference was cited within this specific body of 595 articles.

The most frequently cited article was a 2002 paper in the journal Nature (Coussens and colleagues, Nature volume 420, page 860) that laid the foundation for understanding how inflammation drives cancer. It received 46 citations from the papers in this analysis. The second most cited was a 2010 paper in the journal Cell (Grivennikov and colleagues, Cell volume 140, page 883), cited 38 times. Both are landmark review papers that connected chronic inflammation, immunity, and tumor development, and their citation counts confirm that modern ovarian cancer research is anchored in these foundational ideas.

Citation burst analysis, which identifies papers that suddenly receive intense attention, revealed additional influential works within the field. A three-field diagram linking high-frequency words, authors, and institutions showed that ovarian cancer and inflammation are the most common connecting themes. Harvard University and the NIH are the most productive institutions, while authors WENTZENSEN N and TRABERT B are the most frequent contributors to these central topics.

Key Finding 7: Research Hotspots and Shifting Themes

Keywords are the labels researchers attach to their articles, and tracking them reveals what the scientific community is focusing on. In this analysis, three keywords appeared most frequently overall: ovarian cancer, inflammation, and prognosis. These terms represent the core questions driving the field: How does inflammation shape ovarian cancer, and what does that mean for a patient's likely outcome?

The thematic map of the entire body of research showed that the main research directions are ovulation, gene expression, survival, and inflammation. The field's focus has shifted over time. From 2000 to 2018, the dominant research themes were ovarian cancer, chemoresistance (when tumors stop responding to chemotherapy), C-reactive protein, endometrial cancer, and metastasis (spread of cancer to other organs).

From 2019 to 2024, the themes evolved. Researchers turned their attention to inflammation, cytokines, survival, biomarkers, prognosis, and immunotherapy (treatments that help the immune system fight cancer). Throughout both periods, ovarian cancer and inflammation remained consistently prominent, and the keywords ovarian cancer, inflammation, and prognosis appeared with relatively high frequency. The shift toward immunotherapy and biomarkers signals the direction of future research and represents what the study authors describe as the frontier of this field.

Clinical Implications: What These Findings Mean for Patients

This analysis confirms that chronic inflammation is now considered an important player in ovarian cancer. The mechanisms matter for patients because they point toward new strategies for the disease. Inflammatory cells release reactive oxygen species and cytokines that can damage DNA, activate cancer-promoting genes, and silence protective genes, which in turn helps tumors grow, survive, migrate, and invade nearby tissue.

Specific inflammatory markers are already showing clinical promise. Some studies found that women with ovarian cancer have higher blood levels of C-reactive protein (CRP) and interleukin-6 (IL-6, an inflammatory signaling protein) than healthy women and women with benign (non-cancerous) ovarian disease. Those elevated levels suggest that inflammatory indicators have some value for the early diagnosis of ovarian cancer. Other blood-based ratios, including the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR), are considered potential prognostic indicators. They can reflect how the body is responding to changes in the tumor microenvironment, which is the ecosystem of cells, blood vessels, and immune signals around a tumor. In a large-scale prospective cohort study, high NLR and PLR values were associated with a poor prognosis in ovarian cancer patients.

Even more encouraging is the discovery that the density of certain types of infiltrating macrophages (immune cells that enter the tumor) may increase ovarian cancer risk. This finding points to the importance of the immune microenvironment in how the disease develops. Inflammatory markers can therefore serve a dual role: as a tool for risk assessment and as a possible guide for treatment decisions. The recent surge in research themes around prognosis, biomarkers, and immunotherapy suggests that inflammation-based approaches may eventually help doctors predict which patients will respond to treatment, including emerging immune-based therapies.

The top countries, institutions, and authors identified in this study form a global network. Patients can take some reassurance from the scale of activity: 1,543 institutions in 58 countries are working on these questions, and the pace of publication is accelerating. It is reasonable to expect continued progress in using inflammation markers for early diagnosis and for monitoring patients after treatment.

Limitations: What This Study Could Not Show

Bibliometric analysis is a powerful mapping tool, but it has limits. First, it describes past research trends; it does not test whether any particular marker works for diagnosis or treatment. The underlying clinical evidence about markers like CRP, NLR, and PLR comes from the individual studies included in the map, not from this analysis itself.

Second, the study drew only from the Web of Science Core Collection. Papers published in journals not indexed in that database were excluded, so some relevant research may be missing. The search was also limited to English-language articles and review articles, and it ended on October 31, 2024. Research published after that date is not represented.

Third, citation counts can be influenced by factors other than scientific quality, such as the age of a paper (older papers have had more time to be cited) and academic trends. A highly cited paper is influential but not necessarily correct. Finally, the authors note that the mechanisms by which inflammatory markers specifically affect ovarian cancer progression still require deeper research. Mapping who published what is not the same as proving how inflammation drives the disease or which markers are most useful in the clinic.

Recommendations for Patients

This research summary is not medical advice. Patients should always discuss their individual situation with their oncology care team. That said, the study's findings suggest several points that patients may find useful:

• Know the language of inflammation markers. If your doctor orders blood tests that include CRP, IL-6, NLR, or PLR, these are inflammation-related indicators. They may offer information about your overall inflammatory state and, in some contexts, your prognosis.
• Do not interpret single numbers on your own. Inflammatory marker levels can be affected by many factors, including infections, other medical conditions, and medications. Only your care team can interpret these values in the context of your specific cancer, treatment history, and overall health.
• Understand that this is an evolving field. The rapid growth in publications from 2019 to 2024, especially around biomarkers, prognosis, and immunotherapy, means new knowledge is emerging quickly. Treatment decisions today are based on current evidence, and standards of care may evolve as research advances.
• Ask about clinical trials. If you are interested in the frontier of ovarian cancer research, ask your doctor whether any clinical trials involving inflammatory markers or immunotherapy might be appropriate for your situation.
• Watch for early warning signs. Because inflammatory markers are being studied for early diagnosis, staying attentive to symptoms such as bloating, pelvic pain, feeling full quickly, or urinary symptoms remains important. Report persistent or unusual symptoms to your doctor.

For researchers, the study offers a practical roadmap. The identification of leading countries, institutions, authors, and journals can help new investigators find the most active collaborators in the field. Knowing the most cited foundational papers, such as the 2002 Nature and 2010 Cell reviews on inflammation and cancer, provides an entry point for understanding the scientific roots of this topic.

The study authors conclude that their work is the first bibliometric analysis to comprehensively summarize research trends on inflammatory indicators in ovarian cancer. Their hope is that the results will provide a reference for scholars studying early diagnosis and treatment, and ultimately help move better tools from the laboratory into clinical practice for patients facing this difficult disease.

Frequently Asked Questions

What are inflammation markers and why are they related to ovarian cancer?

Inflammation markers are blood measurements like C-reactive protein (CRP), interleukin-6 (IL-6), and ratios such as neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Inflammatory cells release substances that can damage DNA and help tumors grow, survive, and spread. Researchers are studying these markers for ovarian cancer diagnosis and prognosis.

Can inflammation markers help detect ovarian cancer early?

Some studies found that women with ovarian cancer have higher blood levels of CRP and IL-6 than healthy women or those with benign ovarian disease. This suggests these markers may have some value for early diagnosis. However, the research is still evolving, and these markers are not yet proven as a routine screening tool.

What do NLR and PLR mean for my ovarian cancer prognosis?

NLR is the balance between two types of white blood cells, and PLR compares clotting cells to white blood cells. In a large prospective study, high NLR and PLR values were associated with a poor prognosis in ovarian cancer patients. Your doctor can interpret these values in the context of your individual situation.

Are inflammation markers routinely used in ovarian cancer care?

Inflammatory markers like CRP, IL-6, NLR, and PLR may be ordered by doctors, but they are not a standalone basis for treatment decisions. They provide information about your inflammatory state and possibly prognosis. Only your oncology care team can interpret these tests along with your cancer type, treatment history, and overall health.

What should I do if my blood test shows elevated inflammatory markers?

Do not interpret single numbers on your own. Many factors such as infections, other medical conditions, and medications can affect inflammatory marker levels. Discuss the results with your oncology care team, who can explain what they mean in the context of your specific cancer and treatment plan.

Is there new research on inflammation and ovarian cancer treatment?

Recent research from 2019 to 2024 has focused on inflammation, cytokines, survival, biomarkers, prognosis, and immunotherapy. This suggests inflammation-based approaches may eventually help predict treatment response, including to immune-based therapies. Ask your doctor if any clinical trials involving these markers might be appropriate for you.

Which countries lead ovarian cancer inflammation research?

The United States ranks first and China second in publishing research on inflammation markers in ovarian cancer. Along with others, researchers from 1,543 institutions in 58 countries have contributed to this field. This global network highlights the widespread scientific interest in understanding inflammation's role in ovarian cancer.

Should I get a second opinion on my ovarian cancer treatment plan to understand what my inflammation markers (CRP, NLR, PLR) mean for my prognosis?

Blood-based markers such as CRP, IL-6, NLR, and PLR are being studied as prognostic clues in ovarian cancer. High NLR and PLR values have been associated with poorer prognosis in a large cohort study, but single numbers are not enough to guide treatment. These levels can change with infections, other conditions, and medications, so only your oncology team can interpret them in your full context. Because research from 2019 to 2024 has increasingly focused on biomarkers and immunotherapy, an independent review of your records, markers, and proposed treatment plan can help confirm that your care reflects current scientific understanding. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

This patient-friendly article is based on peer-reviewed research originally published in Frontiers in Oncology.

• Original article title: Knowledge graph and bibliometric analysis of inflammatory indicators in ovarian cancer.