Radiomics-clinical nomogram for response to chemotherapy in synchronous liver metastasis of colorectal cancer: Good, but not good enough

Han Yan,Tu-Nan Yu

Abstract There remains a persistent unmet need to detect the disease nonresponse (nonDR)subgroup before adjuvant therapy in synchronous liver metastasis patients with colorectal cancer. Ma’s radiomics-clinical nomogram shows potential for the early detection of nonDR subgroups, but it is not good enough owing to at least three limitaions, which we address in this letter to the editor. First, the study did not explore RAS/BRAF mutations, HER2 amplifications, etc. to complement the current nomogram. Second, the nomogram was not validated in left- and rightsided tumors separately. Third, the most critical factor for determining the success of adjuvant therapy should be resectability rather than tumor size shrinkage,which was used in the study.

Key Words: Synchronous liver metastasis; Colorectal cancer; Radiomics

TO THE EDITOR

Maet al[1] recently published a novel study investigating the effect of magnetic resonance imagingradiomics in predicting chemotherapeutic response in synchronous liver metastasis (SLM) patients with colorectal cancer (CRC). They proposed a radiomics-clinical nomogram (including the radiomics score,CA19-9, and lymphatic staging) with an area under the curve of 0.809, suggesting high predictive accuracy.

We congratulate the authors for their creative work, as in decision-making for adjuvant therapy in CRC patients with unresectable SLM, there remains a persistent unmet need to detect the disease nonresponse (nonDR) subgroup. Early detection of nonDR patients, aided by the radiomics-clinical nomogram of Ma’s study, could result in substantial changes in subsequent therapeutic plans. For instance, in nonDR cases, more aggressive regimens could be applied instead of the frequently used FOLFOX or CAPOX, such as administration of bevacizumab to inhibit vascular endothelial growth factor or pembrolizumab for immunotherapy. Local regional therapies, including radiofrequency ablation and transcatheter arterial chemoembolization,could also be considered to treat SLM.

However, despite the aforementioned merit, there are at least three limitations to be discussed concerning this nomogram. First, although the authors explored tumor biomarkers, including CEA and CA19-9, to complement radiomics, the statuses of some critical tumor genes (e.g., RAS/BRAF mutations,HER2 amplification, and MSI/MMR status) were not examined, despite the relevant recommendation in the latest National Comprehensive Cancer Network guideline[2]. Second, it is noteworthy that the biological behaviors of CRC differed depending on the anatomical location[3]. For instance, right-sided CRC patients with SLM were unlikely to respond to cetuximab and panitumumab as first-line therapy.Therefore, the performance of Ma’s nomogram should be validated in right- and left-sided CRC separately. Last but not least, the most critical limitation was that the success of adjuvant therapy in CRC patients with SLM should be resectability, rather than tumor size shrinkage used in this study.

In conclusion, in CRC patients with SLM, Ma’s radiomics-clinical nomogram shows potential for clinical utilization. However, it is currently not good enough.

FOOTNOTES

Author contributions:All authors helped to prepare this manuscript; Yan H and Yu TN contributed to manuscript writing, drafting conception and design.

Conflict-of-interest statement:All authors declare that there are no conflicts of interest, and there was no fund

supporting this manuscript.

Open-Access:This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is noncommercial. See: https://creativecommons.org/Licenses/by-nc/4.0/

Country/Territory of origin:China

ORCID number:Han Yan 0000-0001-8189-6678; Tu-Nan Yu 0000-0003-0866-3178.

S-Editor:Gong ZM

L-Editor:A

P-Editor:Gong ZM