The research team, led by surgeons from Zhongshan People’s Hospital and Shenzhen Longhua District People’s Hospital in China, analyzed 383 patients who underwent radical resection of solitary HCC with tumors no larger than 5 centimeters. Every patient had preoperative CTC testing performed three days before surgery, using a technique that combines negative immunomagnetic enrichment with immunofluorescence in situ hybridization. In this method, magnetic beads coated with antibodies against CD45—a marker found on white blood cells—are used to strip away leukocytes from a 5-milliliter peripheral blood sample, enriching the rare malignant cells that have entered the bloodstream through epithelial-mesenchymal transition. The remaining cells are then fixed on slides, hybridized with fluorescent probes targeting the centromeres of chromosomes 1 and 8, stained with DAPI, and counted under a fluorescence microscope. A count of one or more CTCs per sample defined CTC-positive status, a threshold the researchers found correlated strongly with microvascular invasion (MVI), the pathological hallmark of tumor aggressiveness in HCC.

The clinical significance of MVI cannot be overstated. From a pathological standpoint, an HCC lesion is not merely the visible tumor mass; it includes microscopic tumor cell nests invading nearby blood vessels, which a narrow resection margin cannot reliably remove. Previous studies have shown that wide margins reduce early postoperative recurrence in patients with MVI, but offer no such advantage in those without it. The problem has been that MVI can only be confirmed definitively after surgery, when the specimen is examined under a microscope—far too late to guide the surgeon’s hand. Imaging-based prediction models exist, but they lack standardized criteria and show limited accuracy, while subjective assessments such as tumor capsule integrity depend heavily on equipment quality and observer judgment. What the new study demonstrates is that CTC status, detectable in a simple blood draw, serves as a preoperative proxy for MVI, and when combined with tumor diameter measured on routine contrast-enhanced CT or MRI, it creates a decision framework that is both objective and minimally invasive.

The statistical architecture of the study was rigorous. All patients were stratified by tumor size (3 centimeters or less versus more than 3 centimeters) and CTC status (positive versus negative), then further divided by margin width—narrow margins defined as less than 1 centimeter and wide margins as 1 centimeter or more, based on the pathologist-reported shortest macroscopic distance from the tumor edge to the line of transection. Kaplan-Meier survival curves and log-rank tests compared recurrence-free survival (RFS) and overall survival (OS) between groups, while univariate and multivariate Cox regression models identified independent risk factors. A landmark analysis with a 24-month cutoff distinguished early from late recurrence, reflecting the understanding that early recurrences arise from residual microscopic disease while late recurrences more often represent de novo tumors in the diseased liver.

The results revealed a striking stratified effect. In the entire cohort, both tumor diameter and CTC status emerged as independent predictors of RFS and OS. But when the researchers drilled into tumor-size subgroups, something unexpected appeared. For patients with tumors 3 centimeters or smaller—179 patients in total—margin width had no effect on RFS or OS, regardless of CTC status. The MVI rate in this group was only 14.5 percent, and based on multicenter pathological data suggesting that MVI lesions extending more than 1 centimeter from the main tumor account for roughly 28 percent of all MVI in small HCC, the researchers calculated that MVI beyond the 1-centimeter threshold likely occurs in fewer than 4 percent of these patients. In other words, a narrow margin is almost always sufficient to clear the microscopic disease in small tumors, and pursuing wider excision offers no survival benefit while sacrificing liver tissue that cirrhotic patients need to preserve.

The picture changed dramatically for patients with tumors larger than 3 centimeters—204 patients in this subgroup. Here, the MVI rate jumped to 43 percent, consistent with prior findings that tumor size predicts both the incidence and the extent of vascular invasion. When the researchers stratified this group by CTC status, the effect of margin width split cleanly. Among CTC-negative patients with larger tumors, narrow and wide margins produced comparable RFS and OS, with no statistically significant difference. But among CTC-positive patients with tumors exceeding 3 centimeters, wide margins yielded significantly better RFS and OS than narrow margins. Moreover, the landmark analysis showed that wide margins in this CTC-positive subgroup specifically reduced early postoperative recurrence—recurrence within 24 months—while having no effect on late recurrence. This finding aligns precisely with the biological mechanism: early recurrences stem from minimal residual disease left behind at the resection margin, and in patients whose tumors are both large and shedding malignant cells into the bloodstream, that residual burden is substantial enough that only a wider excision can remove it.

The correlation between CTC status and MVI held across both tumor-size groups, reinforcing the biological plausibility of the framework. In patients with tumors 3 centimeters or smaller, the CTC-positive rate was 14.5 percent, and CTC-positive status correlated with MVI at a statistically significant level. In the larger-tumor group, the CTC-positive rate rose to 43.1 percent, and the correlation with MVI was even stronger. Notably, CTC status showed no significant association with other clinicopathological variables, including alpha-fetoprotein levels and tumor differentiation grade, suggesting that it captures a distinct dimension of tumor biology—specifically, the propensity for vascular invasion and hematogenous dissemination—that traditional serum markers and histological grading do not fully reflect.

The study’s authors frame their findings within the broader concept of precision medicine in hepatobiliary surgery. By identifying patients who do not need wide margins—those with small tumors regardless of CTC status, and those with larger tumors that are CTC-negative—surgeons can preserve more functional liver parenchyma, reducing the risk of postoperative liver failure and increasing the option of repeat resection or other multimodal therapies if recurrence does occur. Conversely, for the smaller subset of patients with large, CTC-positive tumors, the data argue for pursuing wide margins, or alternatively, for using preoperative adjuvant therapy to reduce tumor burden before attempting an extended resection. Both variables—CTC count from a peripheral blood draw and tumor diameter from standard cross-sectional imaging—are available before the operation, are objective, and involve minimal patient discomfort, making the framework readily implementable in clinical practice without specialized equipment beyond the CTC detection platform.

The researchers acknowledge important limitations. The retrospective design carries inherent biases and confounding factors that only a prospective study with a larger sample size can eliminate. The cohort was overwhelmingly Chinese and hepatitis B virus-related, raising questions about whether the conclusions apply to non-Asian populations or to patients with hepatitis C-related or alcohol-related HCC. CTC counts may fluctuate over time within the same patient, introducing temporal heterogeneity. The median follow-up of 30 months, while adequate for capturing early recurrence patterns, is insufficient for robust long-term overall survival conclusions beyond five years. And the cost of CTC detection remains high in some regions, though the authors expect this to decrease as detection methods improve. The findings also apply specifically to patients with solitary tumors no larger than 5 centimeters, the population in which the resection margin dilemma is most acute.

Despite these caveats, the study represents a meaningful advance in a field where the optimal margin width has been debated for decades without consensus. Previous attempts to stratify patients by tumor size alone produced contradictory results, with some groups reporting survival benefits from wide margins across all tumor diameters and others, including a well-known Hong Kong study, finding no benefit in any subgroup. By adding CTC status as a second, biologically grounded variable, the researchers have created a two-parameter decision tool that resolves those contradictions and matches surgical aggressiveness to the actual risk of microscopic residual disease. For a cancer that kills nearly 800,000 people each year, and where the difference between a narrow and a wide margin can determine whether a patient keeps enough liver to survive the operation—or enough liver to undergo a second operation if the tumor returns—that kind of preoperative clarity is not just a statistical finding. It is a roadmap for safer, more individualized liver cancer surgery.

Subject of Research: Combined analysis of preoperative circulating tumor cells status and tumor size to guide width of resection margin for solitary hepatocellular carcinoma

Article Title: Combined analysis of preoperative circulating tumor cells status and tumor size to guide width of resection margin for solitary hepatocellular carcinoma

Article References: Xie, J., Luo, Q., Huang, D., Xia, F., Wu, Z., Zhou, W., Zhang, Q., Tian, F., Liu, C.-Y., Xu, Z., Jiao, X.-T., Zhang, W.-Q., Ali, M., Zhou, Y., & Gao, H. (2026). Combined analysis of preoperative circulating tumor cells status and tumor size to guide width of resection margin for solitary hepatocellular carcinoma. Frontiers in Oncology, 16, Article 1810914. https://doi.org/10.3389/fonc.2026.1810914

Image Credits: AI Generated

DOI: 10.3389/fonc.2026.1810914

Keywords: Combined, analysis, preoperative, circulating, tumor, cells, status, size, guide, width, resection, margin