Clinical significance of serum autoantibodies against Ras-like GTPases, RalA, in patients with esophageal squamous cell carcinoma

Six autoantibodies as potential differential biomarkers of hepatocellular carcinoma vs. liver cirrhosis and chronic hepatitis: A prospective multi‑institutional study

Serum autoantibodies respond not only to tumor-associated antigens of hepatocellular carcinoma (HCC) but also to those of liver cirrhosis (LC) and chronic hepatitis (CH). The present prospective multi-institutional study evaluated the diagnostic properties of six autoantibodies in distinguishing HCC from LC and CH. A total of 416 participants were enrolled: 149 With HCC, 76 with LC, 103 with CH and 88 healthy controls. Titers of serum autoantibodies to Sui1, RalA, p62, p53, c-myc and NY-ESO-1 were determined using enzyme-linked immunosorbent assays. All six antibodies were positive for HCC: s-Sui1-Abs (44%), s-RalA-Abs (23%), s-p62-Abs (21%), s-p53-Abs (13%), s-c-myc-Abs (11%) and s-NY-ESO-1-Abs (6%). The positivity rates of all six antibodies combined were 5% for healthy controls, 52% for CH, 58% for LC and 66% for HCC. The positivity rates of s-Sui1-Abs, s-RalA-Abs and s-p53-Abs were higher for HCC compared with those of LC and CH. However, the positivity rates of s-p62-Abs, s-c-myc-Abs and s-NY-ESO-1-Abs for HCC were not higher compared with those for LC and CH. Overall, autoantibodies were useful in differentiating patients with HCC from healthy individuals. However, they were not specific to HCC and were also present in the sera of individuals with CH and LC. These autoantibodies may be induced during the development of HCC. Clinical trial registration number: UMIN000014530 (date of registration 2011/07/11).

Presence of serum RalA and serum p53 autoantibodies in 1833 patients with various types of cancers

BACKGROUND

RalA is a member of the Ras superfamily of small GTPases. The Anti-RalA autoantibodies (s-RalA-Abs) act as tumor markers in various types of cancer and are negatively associated with the p53 autoantibodies (s-p53-Abs). This study aimed to evaluate the relationship between s-RalA-Abs and s-p53-Abs in various types of cancer.

METHODS

A total of 1833 cancer patients (esophageal cancer, 172; hepatocellular carcinoma, 91; lung cancer, 269; gastric cancer, 317; colon cancer, 262; breast cancer, 364; and prostate cancer, 358) and 73 healthy subjects were enrolled in the study. The levels of s-RalA-Abs and s-p53-Abs were analyzed using enzyme-linked immunosorbent assay, and the positivity rates and relations between the two autoantibodies were evaluated. The cutoff values for s-RalA abs and s-p53 abs were set as mean + 2 standard deviation and the values higher than the cutoff values were defined as positive.

RESULTS

The titers in all cancer types were significantly higher than those in the controls (P < 0.01). The positivity rates for s-RalA-Abs ranged between 11.7 and 21.5%, and those for s-p53-Abs ranged between 12 and 28.5%. A combined assay of the two antibodies revealed positivity rates of 20.9 and 44.2%. In Stage 0/I/II tumors, the positivity rates of the combination of the two antibodies ranged between 21.5 and 42.3%. The two autoantibodies were complementary to each other in the prostate and breast cancers, but independent in other carcinomas.

CONCLUSION

The combined use of s-RalA-Abs and s-p53-Abs tended to increase the positivity rate in all cancers, including Stage 0/I/II cancers.

Diagnostic value of serum tumor-associated autoantibodies in esophageal cancer

Aim: To explore the application value of serum autoantibodies in the early diagnosis of esophageal cancer. Materials & methods: A total of 130 patients with esophageal cancer and 110 controls were included and tested by ELISA. Results: According to the receiver operating characteristic curve, total sensitivity is 83.08%, total specificity is 72.73%. A nomogram was established based on the positive judgment standard, the area under the receiver operating characteristic curve was calculated to be 0.880 after verification with the calibration curve. A 2-week follow-up analysis found compared with the preoperative control, the postoperative model integral value will significantly decrease. Conclusion: The combination of serum autoantibody groups has certain clinical application value in the early diagnosis of esophageal cancer and can be used as an auxiliary index for early diagnosis.

Possible predictive significance of serum RalA autoantibodies on relapse-free survival in patients with colorectal cancer

RalA protein, a member of the Ras superfamily of small GTPases, is a tumor antigen that induces serum RalA antibodies (s-RalA-Abs). The present study explored the clinicopathological and prognostic significance of s-RalA-Abs in patients with colorectal cancer. Serum samples were obtained from 314 patients with colorectal cancer at stage 0/I (n=71), stage II (n=86), stage III (n=78), stage IV (n=64) and recurrence (n=15). Samples were analyzed for the presence of s-RalA-Abs using ELISA. The cutoff optical density value was fixed at 0.324 (mean of heathy controls + 3 standard deviations). The overall positive rate for serum anti-RalA antibodies was 14%. The presence of s-RalA-Abs was not significantly associated with clinicopathological characteristic factors. Additionally, the s-RalA-Abs(+) group demonstrated significantly poor relapse-free survival rates. The s-RalA-Abs (+)/carcinoembryonic antigen (CEA)(+) group exhibited the worst prognosis and s-RalA-Abs(+)/CEA(+) was an independent risk factor for poor relapse-free survival. Although the positive rate was not high, s-RalA-Abs may be a useful predictor of poor relapse-free survival in patients with colorectal cancer.

Six autoantibodies as potential serum biomarkers of hepatocellular carcinoma: A prospective multicenter study

Serum autoantibodies have been reported to react with tumor-associated antigen (TAA) in various cancers. This multicenter study evaluated the diagnostic and prognostic value of six autoantibodies against a panel of six hepatocellular carcinoma (HCC)-associated antigens, including Sui1, p62, RalA, p53, NY-ESO-1 and c-myc. A total of 160 patients with HCC and 74 healthy controls were prospectively enrolled from six institutions. Serum antibody titers were determined by enzyme-linked immunosorbent assays. The sensitivities were 19% for Sui1, 18% for p62, 17% for RalA, 11% for p53, 10% for NY-ESO-1 and 9% for c-myc. Overall sensitivity of the TAA panel (56%) was higher than that of α-fetoprotein (41%, P < .05). The combined sensitivity of the TAA panel and α-fetoprotein was significantly higher than that of α-fetoprotein alone (P < .001). The difference in overall survival of TAA panel-positive and panel-negative patients was significant when the Stage I/II patients were combined (P = .023). Overall survival was worse in NY-ESO-1 antibody-positive than in NY-ESO-1 antibody-negative patients (P = .002). Multivariate analysis found that positivity for the TAA panel was independently associated with poor prognosis (P = .030). This TAA panel may have diagnostic and prognostic value in the patients with HCC.