Ratio of CA19-9 level to total bilirubin as a novel prognostic indicator in patients with pancreatic head carcinoma following curative resection

Single-cell RNA sequencing reveals the process of CA19-9 production and dynamics of the immune microenvironment between CA19-9 (+) and CA19-9 (-) PDAC

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the main types of malignant tumor of the digestive system, and patient prognosis is affected by difficulties in early diagnosis, poor treatment response, and a high postoperative recurrence rate. Carbohydrate antigen 19-9 (CA19-9) has been widely used as a biomarker for the diagnosis and postoperative follow-up of PDAC patients. Nevertheless, the production mechanism and potential role of CA19-9 in PDAC progression have not yet been elucidated.

METHODS

We performed single-cell RNA sequencing on six samples pathologically diagnosed as PDAC (three CA19-9-positive and three CA19-9-negative PDAC samples) and two paracarcinoma samples. We also downloaded and integrated PDAC samples (three each from CA19-9-positive and CA19-9-negative patients) from an online database. The dynamics of the proportion and potential function of each cell type were verified through immunofluorescence. Moreover, we built an in vitro coculture cellular model to confirm the potential function of CA19-9.

RESULTS

Three subtypes of cancer cells with a high ability to produce CA19-9 were identified by the markers TOP2A, AQP5, and MUC5AC. CA19-9 production bypass was discovered on antigen-presenting cancer-associated fibroblasts (apCAFs). Importantly, the proportion of immature ficolin-1 positive (FCN1+) macrophages was high in the CA19-9-negative group, and the proportion of mature M2-like macrophages was high in the CA19-9-positive group. High proportions of these two macrophage subtypes were associated with an unfavourable clinical prognosis. Further experiments indicated that CA19-9 could facilitate the transformation of M0 macrophages into M2 macrophages in the tumor microenvironment.

CONCLUSIONS

Our study described CA19-9 production at single-cell resolution and the dynamics of the immune atlas in CA19-9-positive and CA19-9-negative PDAC. CA19-9 could promote M2 polarization of macrophage in the pancreatic tumor microenvironment.

Preoperative Alkaline Phosphatase-adjusted CA19-9 as a Superior Prognosticator for Extrahepatic Biliary Tract Cancer With Jaundice

BACKGROUND/AIM

The major limitation of carbohydrate antigen (CA)19-9 as a tumor marker is the high incidence of false-positive results during cholestasis. We evaluated preoperative CA19-9 and its adjusted values [ratios of CA19-9 to total-bilirubin (TB), direct-bilirubin (DB), and alkaline phosphatase (ALP)] to investigate the most suitable prognostic parameter in extrahepatic biliary tract cancer (eBTC) patients with or without jaundice.

PATIENTS AND METHODS

eBTC patients (n=140) who underwent resection were divided based on the absence (TB <2.0 mg/dl, n=90) or presence (TB ≥2.0 mg/dl, n=50) of preoperative jaundice. Within each group, the associations with overall survival (OS) were assessed for CA19-9, CA19-9/TB, CA19-9/DB and CA19-9/ALP ratios using Cox regression, receiver operating characteristic (ROC) analyses, and area under the curve (AUC) estimates.

RESULTS

In univariate analysis in the group without jaundice, both high CA19-9 and high CA19-9/TB ratio were associated with poor OS, whereas other parameters were not. ROC-AUC for OS prediction was greater in CA19-9 than in the CA19-9/TB ratio, and CA19-9 was identified as an independent prognosticator in multivariate analysis. In the group with jaundice, CA19-9 was not significant; however, CA19-9/TB, CA19-9/DB, and CA19-9/ALP ratios were all associated with poor OS. In ROC-AUC analysis, CA19-9/ALP ratio showed the highest predictive value; furthermore, it was an independent prognosticator in multivariate analysis.

CONCLUSION

Adjustment of the CA19-9 value was less useful as a predictor in the absence of jaundice. On the other hand, the CA19-9/ALP ratio showed superior prognostic value in jaundiced patients with eBTC.

Adjusting CA19-9 values with clinical stage and bilirubin to better predict survival of resectable pancreatic cancer patients: 5-year-follow-up of a single center

Background

Pancreatic cancer mortality is growing every year, and radical resection is the most essential therapy strategy. It is critical to evaluate the long-term prognosis of individuals receiving radical surgery. CA19-9 is a biomarker for patient recurrence and survival, however obstructive jaundice has a significant impact on this index. Researchers have attempted to modify the index using various modification methods, but the results have been unsatisfactory. In this study, we adjusted CA19-9 values based on clinical stage and bilirubin and found that it provided better prediction than CA19-9 alone in assessing patients.

Methods

We analyzed over 5 years follow-up records of patients who underwent radical pancreatic cancer surgery between August 2009 and May 2017 in a single center. We investigated the association of risk factors with overall survival (OS) as well as disease-free survival (DFS) after surgery. Threshold values for high-risk features associated with poor prognosis in resectable pancreatic cancer were determined. The hazard ratios of the indicators were eventually examined under the stratification of patients’ clinical stages.

Results

A total of 202 patients were involved in the study. The optimum cut-off values for CA19-9 and CA19-9/TB for predicting overall survival were 219.4 (p = 0.0075) and 18.8 (p = 0.0353), respectively. CA19-9>219.4 increased the risk of patient mortality by 1.70 times (95% CI 1.217-2.377, p = 0.002), and tumor poor differentiation raised the risk by 1.66 times (95% CI 1.083-2.553, P = 0.02). Based on clinical stage stratification, we found discrepancies in the predictive efficacy of CA19-9 and CA19-9/TB. CA19-9 was a better predictor in clinical stage 1 (HR = 2.056[CI 95%1.169-3.616], P = 0.012), whereas CA19-9/TB indications were better in stages 2 (HR = 1.650[CI 95%1.023-2.662], P = 0.040) and 3 (HR = 3.989[CI95%1.145-13.896], P = 0.030).

Conclusions

CA19-9, CEA, and tumor differentiation are predictors for patients with resectable PDAC. CA19-9 values can be adjusted based on clinical stage and bilirubin levels to better predict overall survival in patients with resectable PDAC. CA19-9>219.4 predicted poor survival in individuals in clinical stage 1, whereas CA19-9/TB>18.8 predicted poor survival for individuals in stages 2 and 3.