Core Tip: Primary tumor location is a master prognostic regulator in colorectal liver metastases. Right-sided origin defines an aggressive biologic phenotype, marked by chemoresistance, hypercoagulability, and systemic decline, culminating in a more than 50% 1-year recurrence rate and a 13-month survival deficit. These findings mandate abandoning a one-size-fits-all management approach. Therefore, the immediate implementation of the following site-specific protocols remains paramount: Preoperative risk stratification, therapeutic intensification, and personalized intensive surveillance for right-sided cases.
TO THE EDITOR
The operative management of colorectal liver metastases (CRLM) is evolving. Historically, surgical strategy and prognostication have been guided primarily by the technical resectability and burden of metastatic disease within the liver[
1]. Within this paradigm, the primary colorectal tumor has often been considered a historical footnote. The work by Liu
et al[
2] now challenges this established view, providing robust data that position the primary tumor site as a principal determinant of postoperative outcomes. Their evidence compels a critical re-evaluation of our current, relatively uniform treatment approaches. These evolving principles are summarized in
Table 1.
The analysis by Liu
et al[
2] is methodologically rigorous, moving beyond simple association to identify independent predictors. Through multivariate logistic regression, right-sided origin was isolated as an independent predictor of recurrence (odds ratio: 1.74). This predictive power is contextualized within a syndromic complex of adverse features, positioning the primary tumor site as a central component of a high-risk phenotype[
2,
3]. The data reveal a consistent pattern: Right-sided tumors are linked to markers of aggressive biology[
2,
4]. The clinical and biologic profile of right-sided colorectal liver metastases is detailed in
Table 2. They exhibit a markedly high rate of lymph node metastases (91%), indicative of advanced metastatic competence. Furthermore, they are associated with a systemic pro-thrombotic state (elevated D-dimer) and cancer-associated systemic decline (hypoalbuminemia), which may impair host immunity and facilitate metastatic progression[
2,
5]. Notably, these tumors also demonstrate pronounced resistance to neoadjuvant therapy. The clinical consequence of this biologic profile is a 12-month recurrence rate exceeding 55% and a median overall survival of approximately 28.5 months.
The association between right-sided origin and inferior outcomes is underpinned by well-established biologic distinctions. The embryonic origin, mucosal microenvironment, and immune landscape of the right and left colon are fundamentally different[
5]. Carcinomas arising in the right colon are frequently enriched for specific molecular subtypes, particularly the consensus molecular subtype 4. This “mesenchymal” phenotype is characterized by prominent transforming growth factor β signaling, stromal activation, and angiogenesis, which collectively drive invasive capacity and treatment resistance[
6]. This molecular framework provides a plausible explanation for the observed clinical aggressiveness.
The translation of these insights into clinical practice necessitates a structured approach. First, primary tumor location should be integrated as a key variable in preoperative risk assessment[
5]. Patients with right-sided CRLM may be appropriately classified as high-risk, which could justify enhanced staging with positron emission tomography computed tomography to exclude occult extrahepatic disease[
7]. This stratification also supports the implementation of aggressive prehabilitation protocols to address associated systemic vulnerabilities. Second, the observed resistance to neoadjuvant therapy in this subgroup supports the consideration of intensified systemic regimens. For patients with right-sided CRLM, initial therapy should involve the most efficacious available options[
8], which may include first-line triplet chemotherapy combined with biologic agents such as bevacizumab[
9]. A concerted surgical effort to achieve a parenchymal margin greater than 1 cm is also prudent. Third, the significant recurrence risk mandates a surveillance protocol of heightened intensity. For patients with right-sided primaries, cross-sectional imaging at 3-month intervals for the initial 2-3 years post-operatively is a rational strategy to enable early detection of recurrence.
The primary tumor site is a fundamental prognostic variable in the surgical management of CRLMs. Right-sided origin defines a distinct clinicopathologic entity characterized by an aggressive biological signature and inferior outcomes. The evidence strongly suggests that treatment strategies should be personalized accordingly. The adoption of a site-specific management paradigm represents a critical and necessary step toward improving outcomes for patients with right-sided CRLMs.
Supplementary Materials
The following supporting information can be downloaded at the website of this paper posted on Preprints.org.
Author Contributions
Omullo FP was solely responsible for the conceptualization, drafting, critical revision, and final approval of this manuscript.
Conflicts of Interest
The author reports no relevant conflicts of interest for this article.
References
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Table 1.
Evolving paradigms in the management of colorectal liver metastases.
Table 1.
Evolving paradigms in the management of colorectal liver metastases.
| Principle |
Traditional paradigm |
New, biology-driven paradigm |
| Defining logic |
Technical resectability of metastatic disease |
Inherent biological aggressiveness of the primary tumor |
| Central prognostic factor |
Metastatic burden (number and size of lesions) |
Primary tumor location and its associated biologic phenotype |
| Role of primary tumor |
Historical point of origin |
Key regulator of metastatic behavior and host systemic response |
| Therapeutic goal |
Standardised application guidelines |
Risk-adapted site-specific intensification of multimodal therapy |
| Implied action |
Uniform treatment protocols |
Location-defined and molecular-informed treatment algorithms |
Table 2.
The clinical and biologic profile of right-sided colorectal liver metastases.
Table 2.
The clinical and biologic profile of right-sided colorectal liver metastases.
| Clinical domain |
Manifestations in right-sided CRLM[1] |
Proposed biological driver |
Actionable clinical response |
| Metastatic aggression |
High lymph node metastasis rate; > 55% 12-month recurrence |
CMS4 mesenchymal phenotype; enhanced invasive capacity |
Enhanced staging; pursuit of wider surgical margins |
| Systemic environment |
Elevated D-dimer; hypoalbuminemia |
Tumor-induced hypercoagulability; cancer-associated systemic inflammation |
Consider perioperative anticoagulation; mandatory prehabilitation |
| Therapeutic resistance |
High rate of poor neoadjuvant response |
Distinct molecular drivers (e.g., BRAF); enriched chemoresistant pathways |
First-line therapy intensification; early biomarker integration |
| Ultimate outcome |
Diminished median overall survival |
Synergistic effect of an aggressive biologic phenotype |
Classify as “ultra-high risk”; implement intensive, personalised surveillance |
|
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