Exploration of a novel prognostic model based on nomogram in non-small cell lung cancer patients with distant organ metastasis: implications for immunotherapy

Background

Evidence for the effects of immunotherapy in non-small cell lung cancer (NSCLC) patients with distant organ metastasis is insufficient, and the predictive efficacy of established markers in tissue and blood is elusive. Our study aimed to determine the prognostic factors and develop a survival prognosis model for these patients.

Methods

A total of 100 advanced NSCLC patients with distant organ metastases, who received single or combination immune checkpoint inhibitors (ICIs) in Xijing Hospital between June 2018 and June 2021, were enrolled for retrospective analysis. The major clinicopathological parameters were collected, and associated survival outcomes were followed up by telephone or inpatient follow-up for nearly 3 years to assess prognoses. The survival prognosis model was established based on univariate and multivariate Cox regression analyses to determine the candidate prognostic factors.

Results

From the start of immunotherapy to the last follow-up, 77 patients progressed and 42 patients died, with a median follow-up of 18 months [95% confidence interval (CI): 15-19.9]. The median progression-free survival (PFS) and overall survival (OS) were 8 months (95% CI: 5.6-10.4) and 21 months (95% CI: 8.9-33.1), respectively. Multivariate Cox proportional hazards analysis showed Eastern Cooperative Oncology Group performance status (ECOG PS), body mass index (BMI), age-adjusted Charlson comorbidity index (ACCI), lactate dehydrogenase (LDH), and absolute neutrophil count (ANC) were correlated significantly with OS. Based on these five predictive factors, a nomogram and corresponding dynamic web page were constructed with a concordance index (C-index) of 0.81 and a 95% CI of 0.778-0.842. Additionally, the calibration plot and time-receiver operating characteristic (ROC) curve validated the precision of the model at 6-, 12-, and 18-month area under the curves (AUCs) reached 0.934, 0.829, and 0.846, respectively. According to the critical point of the model, patients were further divided into a high-risk total point score (TPS) >258, middle-risk (204< TPS ≤258), and low-risk group (TPS ≤204), and significant OS differences were observed among the three subgroups (median OS: 4.8 vs. 13.0 vs. 32.9 months).

Conclusions

A feasible and practical model based on clinical characteristics has been developed to predict the prognosis of NSCLC patients with distant organ metastasis undergoing immunotherapy.

Organ Specific Copy Number Variations in Visceral Metastases of Human Melanoma

Malignant melanoma is one of the most aggressive skin cancers with high potential of visceral dissemination. Since the information about melanoma genomics is mainly based on primary tumors and lymphatic or skin metastases, an autopsy-based visceral metastasis biobank was established. We used copy number variation arrays (N = 38 samples) to reveal organ specific alterations. Results were partly completed by proteomic analysis. A significant increase of high-copy number gains was found in an organ-specific manner, whereas copy number losses were predominant in brain metastases, including the loss of numerous DNA damage response genes. Amplification of many immune genes was also observed, several of them are novel in melanoma, suggesting that their ectopic expression is possibly underestimated. This "immunogenic mimicry" was exclusive for lung metastasis. We also provided evidence for the possible autocrine activation of c-MET, especially in brain and lung metastases. Furthermore, frequent loss of 9p21 locus in brain metastases may predict higher metastatic potential to this organ. Finally, a significant correlation was observed between BRAF gene copy number and mutant allele frequency, mainly in lung metastases. All of these events may influence therapy efficacy in an organ specific manner, which knowledge may help in alleviating difficulties caused by resistance.

CD169+ lymph node macrophages have protective functions in mouse breast cancer metastasis

Although the contribution of macrophages to metastasis is widely studied in primary tumors, the involvement of macrophages in tumor-draining lymph nodes (LNs) in this process is less clear. We find CD169⁺ macrophages as the predominant macrophage subtype in naive LNs, which undergo proliferative expansion in response to tumor stimuli. CD169⁺ LN macrophage depletion, using an anti-CSF-1R antibody or clodronate-loaded liposomes, leads to increased metastatic burden in two mouse breast cancer models. The expansion of CD169⁺ macrophages is tightly connected to B cell expansion in tumor-draining LNs, and B cell depletion abrogates the effect of CD169⁺ macrophage absence on metastasis, indicating that the CD169⁺ macrophage anti-metastatic effects require B cell presence. These results reveal a protective role of CD169⁺ LN macrophages in breast cancer metastasis and raise caution for the use of drugs aiming at the depletion of tumor-associated macrophages, which might simultaneously deplete macrophages in tumor-draining LNs.

Usefulness of plasma D-dimer level for monitoring development of distant organ metastasis in colorectal cancer patients after curative resection

Purpose

To investigate the usefulness of plasma D-dimer level for monitoring the development of distant organ metastasis in colorectal cancer (CRC) patients after curative resection.

Patients and methods

One hundred and seventy-eight CRC patients after curative resection were enrolled in the study. Ninety-two patients developed distant organ metastasis during follow-up (metachronous metastasis), and blood was collected on the day metastasis was confirmed. Eighty-six patients had no evidence of metastasis yet, and their blood samples were evaluated at last return visit. The levels of D-dimer, carcinoembryonic antigen (CEA), and lactate dehydrogenase (LDH) between two patient groups were compared. The agreement between D-dimer and CEA (or LDH) was examined. The receiver operator characteristic (ROC) curve was used to evaluate the performance of D-dimer, CEA, LDH, and their combination in detection of distant organ metastasis.

Results

The level of D-dimer in CRC patients with metachronous metastasis was higher than that in non-metastasis patients (P<0.0001). Agreement between D-dimer and CEA was fair (κ=0.416, P<0.0001). D-dimer had a larger area under ROC (AUC) (0.85) compared to CEA (0.72) or LDH (0.68). The specificity of D-dimer (73.3%) was lower than that of CEA (74.4%), but the sensitivity (88.0%) of D-dimer assay was superior to that of CEA assay (65.2%). LDH showed the lowest sensitivity (42.4%) and highest specificity (95.3%) among the three bio-markers. The sensitivity and negative predictive value (NPV) of a combination assay (either D-dimer elevation or CEA elevation) were 94.6% and 91.1%, respectively, and the specificity and positive predictive value of another combination assay (both D-dimer elevation and LDH elevation) were 97.7% and 94.9%, respectively. Parallel test of the three markers improved the sensitivity and NPV to 95.7% and 92.7%, respectively.

Conclusion

Combining with CEA and/or LDH, D-dimer could be a useful surveillance marker for distant organ metastasis in CRC patients after curative resection.