Researchers looked at health data from nearly 14,000 women collected over 20 years to understand if certain blood markers could help predict breast cancer risk. They found that two specific blood measurements—one showing the balance between immune cells and protein levels—were connected to breast cancer risk. Women with higher levels of one marker (NPAR) had increased risk, while women with higher levels of another marker (LYAR) had lower risk. These simple blood tests might help doctors identify which women need closer monitoring, though more research is needed before doctors use them routinely.

The Quick Take

  • What they studied: Whether certain measurements in blood (specifically the balance between immune cells and a protein called albumin) could help predict a woman’s risk of developing breast cancer
  • Who participated: 14,211 women aged 20-80 who participated in a large U.S. health survey between 1998 and 2018. Of these women, 357 had been diagnosed with breast cancer
  • Key finding: Women with higher NPAR scores (a ratio of certain immune cells to albumin) had about 60% higher breast cancer risk compared to women with lower scores. In contrast, women with higher LYAR scores (a different ratio) had lower breast cancer risk
  • What it means for you: These blood tests may eventually help doctors identify which women are at higher risk for breast cancer, allowing for earlier monitoring. However, these tests are not yet recommended for routine use—talk to your doctor about your individual breast cancer risk factors

The Research Details

This study used information from the National Health and Nutrition Examination Survey, a large ongoing project that tracks the health of Americans. Researchers looked back at data collected from 1998 to 2018 and identified women who had developed breast cancer during this time. They then compared the blood test results of women with breast cancer to those without it, looking specifically at four different measurements that combine immune cell counts with albumin (a protein in blood that reflects nutrition and inflammation). The researchers used statistical methods to determine if these blood measurements were connected to breast cancer risk, and they tested whether the relationships were straight lines or more complex patterns.

This approach is important because it uses real-world health data from a large, diverse group of Americans rather than a small laboratory study. The long time period (20 years) allows researchers to see which women actually developed breast cancer, making the findings more reliable. By studying multiple blood markers at once, researchers can understand which ones are most useful for predicting risk

This study has several strengths: it includes a large number of participants, uses data from a well-established national health survey, and tests findings multiple ways to make sure results are reliable. However, because this is a cross-sectional study (looking at data from one point in time), it shows associations but cannot prove that these blood markers directly cause breast cancer. The study also cannot explain why these markers are connected to breast cancer risk

What the Results Show

The most important finding involved NPAR (neutrophil percentage-to-albumin ratio), which measures the balance between certain immune cells and albumin protein. Women with the highest NPAR levels had about 60% higher breast cancer risk compared to women with the lowest levels. This relationship was consistent and linear, meaning risk increased steadily as NPAR levels went up. The second important finding involved LYAR (lymphocyte-to-albumin ratio), a different immune cell-to-albumin measurement. This marker showed the opposite pattern: women with higher LYAR levels had lower breast cancer risk. Interestingly, this protective relationship was not a simple straight line but followed a more complex pattern. The other two markers tested (leukocyte-to-albumin ratio and platelet-to-albumin ratio) did not show meaningful connections to breast cancer risk.

When researchers looked at specific groups of women (different ages, races, and health conditions), the main findings held up consistently. This suggests that NPAR and LYAR may be useful across different populations. The protective effect of LYAR was particularly strong, suggesting that maintaining higher levels of this lymphocyte-to-albumin ratio might be beneficial

This research builds on growing evidence that inflammation and nutritional status play roles in cancer development. Previous studies have shown that inflammation markers are connected to various cancers, but this is one of the first studies to specifically examine these albumin-related markers in relation to breast cancer risk using a large U.S. population. The findings align with the theory that inflammation increases cancer risk while good nutritional status (reflected by albumin levels) may be protective

This study cannot prove that these blood markers cause breast cancer—only that they are associated with it. The study design means researchers cannot determine the direction of the relationship or rule out other explanations. Additionally, the study only included data on whether women had breast cancer at the time of the survey, not detailed information about cancer stage or type. The researchers also could not account for all possible factors that influence breast cancer risk, such as family history or hormone therapy use

The Bottom Line

These findings suggest that NPAR and LYAR blood tests may eventually be useful tools for identifying women at higher breast cancer risk (moderate confidence level). However, these tests are not yet ready for routine clinical use. Women should continue following standard breast cancer screening recommendations from their doctors and discuss their individual risk factors. If you have concerns about breast cancer risk, talk to your healthcare provider about appropriate screening and prevention strategies

These findings are most relevant to women concerned about breast cancer risk and healthcare providers looking for new screening tools. Women with family histories of breast cancer, those over 40, and those with other risk factors should be especially interested. However, these results should not replace current screening methods like mammograms. Men should note that this study focused on women only

If these blood tests are eventually adopted for clinical use, they would provide information relatively quickly since they are simple blood tests. However, it typically takes 5-10 years of additional research before new biomarkers move from research studies to routine clinical practice

Want to Apply This Research?

  • Track your annual blood work results, specifically noting NPAR and LYAR values if your doctor orders them. Record these alongside other health markers like cholesterol and blood sugar to identify patterns over time
  • Use the app to monitor lifestyle factors that influence inflammation and nutritional status: track anti-inflammatory foods (like fatty fish, berries, and leafy greens), protein intake, exercise minutes, and sleep quality. These factors may influence the blood markers identified in this study
  • Set reminders for annual health checkups where you can discuss these emerging biomarkers with your doctor. Use the app to maintain a health history timeline, noting any new health conditions or changes in blood work results, which can help you and your doctor identify trends

This research describes associations between blood markers and breast cancer risk but does not establish cause-and-effect relationships. These blood tests are not currently recommended for routine breast cancer screening and should not replace standard screening methods like mammograms. The findings are preliminary and require further research before clinical application. Always consult with your healthcare provider about your individual breast cancer risk, appropriate screening methods, and prevention strategies. This information is for educational purposes only and should not be used for self-diagnosis or treatment decisions.