Is it possible to predict the presence of colorectal cancer in a blood test? A probabilistic approach method

Blood-Cell-Based Inflammatory Markers as a Useful Tool for Early Diagnosis in Colorectal Cancer

Background

Systemic inflammation seems to be involved in the pathogenetic pathways of colorectal cancer (CRC). Analytical markers that reflect the inflammatory status, such as neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) or systemic immune-inflammation index (SII), have been proposed as tools for the prognosis of CRC. Nevertheless, their use for diagnosis has been scarcely investigated.

Aims

To analyze the ability of these markers and of a new marker combining SII and hemoglobin concentration, named NP/LHb = [neutrophils x platelets]/[lymphocytes x hemoglobin], as tools for CRC diagnosis. Furthermore, we studied their association with CRC-related variables.

Methods

Case-control study including 214 CRC patients and 214 controls without CRC, matched by age (±5 years) and sex. We collected demographic, CRC-related and laboratory variables to calculate NLR, PLR, SII, and NP/LHb. In the case group, the laboratory variables were collected at two different period times, 6 months (IQR 4–8) before the CRC diagnosis and at the time of the diagnosis. ROC analysis was performed to evaluate the discriminatory accuracy of each index and we calculated Se, Sp, PPV, NPV, and OR to identify the diagnostic performance of each positive marker.

Results

NP/LHb showed high Sp (92.06%) and PPV (87.50%) to diagnose patients with CRC. This index exhibited an OR of 14.52 (8.26–25.52) and the best area under the curve (AUC: 0.78) for a positive CRC diagnosis. We found significant differences in all indices according to the presence of CRC, observing the highest values in CRC patients at time of diagnosis, in comparison with the analysis performed in the previous months to diagnosis or with control patients. There were significant differences in all ratios according to TNM stages (p < 0.05). PLR, SII and NP/LHb (but not NLR) showed significant differences according to tumor location (p < 0.05). Right-sided colon cancers presented the highest values, in comparison with left-sided and rectal cancers.

Conclusions

Systemic inflammatory cell ratios (especially NP/LHb) change over time with the development of CRC, so they could be useful in its early diagnosis. We suggest that they could be routinely measured in patients with suspicion of CRC, to identify those ones with a higher risk of cancer, considering the high positive predictive value they have shown in our study.

The clinical significance of preoperative plasma fibrinogen levels and platelet counts in resectable colon cancer

BACKGROUND AND AIM

Several aspects of the correlation between colon cancer and hemostatic markers are still unknown to many researchers in the field. In this study, we evaluated the association, if any, of preoperative platelet (PLT) counts and plasma fibrinogen levels with postoperative lymph node involvement and venous invasion in colon cancer patients.

METHODS

This study retrospectively included eighty patients with colon cancer (mean age 58.09 years; 37% female 63% male).

RESULTS

Patients with negative lymph nodes and venous invasion showed a significantly lower PLT count and higher fibrinogen level than their counterparts, i.e., patients with positive lymph nodes (p<0.001, all of them) and venous invasion (p<0.001, all of them). The results also showed a positive association of PLT counts and fibrinogen levels with lymphatic invasion (r=0.670, p<0.001 and r=0.639, p<0.001, respectively) and a positive association of PLT counts and fibrinogen levels with venous invasion (r=0.3988, p<0.001 and r=0.5268, p<0.001, respectively). According to the results of the ROC curve analysis, when the PLT count cutoff was 290/mm³, the sensitivity and specificity were 82% and 86.67%, respectively (AUC = 0.8840, p<0.0001, 95% CI 0.8084-0.9596). When the fibrinogen level cutoff was 310.0 mg/dL, the sensitivity and specificity were 72% and 96.67%, respectively (AUC 0.8790, p <0.0001, 95% CI 0.8067-0.9513).

CONCLUSION

The preoperative PLT count and plasma fibrinogen level may be considered key markers to monitor postoperative lymph node involvement and venous invasion in colon cancer patients.