This study, with multiple post-treatment and immune-based prognostic scores, aimed to investigate the prognostic role of post-treatment 6th-week NLR, PLR, LIPI, and mGPS scores in patients with locally advanced or metastatic lung cancer. Pretreatment NLR, PLR, LIPI, and mGPS is a manifestation of baseline immune function, their posttreatment results are theoretically modifiable factors that could be influenced by several factors, such as radiation prescriptions or therapy dosing. These findings may indicate a potential predictive marker of response. Eighty-three patients were examined, revealing that post-treatment NLR, PLR, LIPI, and mGPS were statistically significantly associated with poor prognosis in the study population. Besides determining a predictive value, our data also demonstrated an independent association with survival.
There are multiple research articles and meta-analyses about the prognostic effect of pretreatment NLR in lung cancer but changes of NLR status depending on treatment have not yet been determined. Our hypothesis was that post-treatment NLR and NLR dynamics after immunotherapy would be prognostic. In our study, posttreatment NLR values (> 5) up to the threshold had shorter PFS, shorter OS, and lower RR, consistent with all previous study results. In univariate analysis, all inflammatory parameters were independent prognostic indicators, but on multivariate analysis, only OS had relevant results with NLR. In one study, 54 patients with NSCLC were treated with anti-PD-1 treatment, NLR was assessed at baseline and 6 weeks, and low post-treatment NLR (> 5) and immune-related adverse events were significantly associated with low response, shorter PFS, and OS. Liver metastasis was also an independent prognostic indicator of shorter PFS.(14) Another study on patients with NSCLC who received conventional chemotherapy and gefitinib demonstrated that an early reduction in NLR was a surrogate marker of survival.(15)
The backbone treatment for patients with advanced NSCLC is platinum with cytotoxic chemotherapy.(16) We know about chemotherapy-induced neutropenia associated with increased survival in patients with advanced NSCLC.(17) Neutropenia should be a surrogate marker of chemotherapy efficacy, deficient neutropenia in patients may indicate insufficient dosing and inadequate tumor elimination.(18) Neutrophils can also be manipulated to develop different functional polarization and phenotypic states, which induces antitumor or protumor effects In the tumor microenvironment.(19) Finally, the patterns of NLR change after the 6th week of treatment as a prognostic factor for PFS and OS were consistent with immunotherapy treatment regimens.
High platelet levels have an active role in inflammation, tissue regeneration, or acceleration of tumor progression.(20) In contrast, lymphocytes release some types of cytokines that activate anti-tumor immunity.(21) Recently, elevated PLR was shown to be closely related to poor prognosis in various solid tumors.(22) Our study shows that PLR level elevation during the 6th week of ICI treatment was significantly associated with the initial response, PFS, and OS of ICI treatment. We should speculate that differences between studies in cancer type, demographic specialties, treatment modalities, sample size, and the threshold PLR value used to bisection may be responsible. In patients with NSCLC receiving predominately nivolumab or pembrolizumab, higher PLR has been correlated with worse OS.(23) A metanalysis of 12 studies reported that pretreatment PLR could be a routine potential prognostic factor and have a predictive role concerning the survival of patients with cancer treated with immunotherapy.(24) Another two studies related to NSCLC found no significant difference in survival between patients with NSCLC with high and low baseline PLR levels [15.4, 15.5].(25–26)
In 2018, Mezquita et al. (27) developed a new potential blood-based biomarker, LIPI, which stratified baseline dNLR and LDH, in patients with NSCLC under anti-PDL1 treatment according to survival outcomes. Previous studies indicated that LIPI could predict clinical outcomes across many tumor types, such as renal cell carcinoma, melanoma, small-cell lung cancer, and especially NSCLC; however, the prognostic value of LIPI remains a divisive issue. Mostly, the combination of baseline dNLR and LDH is correlated with resistance to ICI therapy in patients with advanced NSCLC. We also explored the predictive value of LIPI in these contexts. The present study shows that the intermediate LIPI group had significantly different response rates compared with the poor group during the 6th week of ICI treatment. Also, the poor LIPI group versus had worse OS and PFS with ICI treatment compared with the good group.
The LDH level is a known prognostic inflammatory marker in patients with cancer and has been widely studied in lung cancer treated with chemotherapy or patients with EGFR-mutant NSCLC. LDH was associated with DCR, PFS, and OS during the first month of erlotinib treatment.(28) Neutrophils are a crucial component of inflammation, playing an essential role in initiating tumorigenesis by damaging specific tissues. In cancer, neutrophils can promote or prevent tumor progression. Both increased and decreased neutrophil counts have been associated with tumor initiation.(29) Another mechanism is the neutrophil pro-inflammatory status, which induces uncontrolled granulopoiesis, releasing immature or poorly differentiated neutrophils, and has been associated with tumor progression.(30)
The exact mechanisms of inflammation related to prognosis remain unclear.(2) One of the suggested pathways should identify with GPS. There are increasing data showing the presence of patient-related factors, especially nutritional and functional status, associated with poorer outcomes in addition to the tumor stage. mGPS has been used as a biomarker to reflect the degree of cancer-associated inflammation and malnutrition. mGPS is a kind of systemic inflammatory response (SIR) based scoring system that combines the indicators of decreased plasma albumin and elevated CRP.(31) In our study, patients with higher mGPS showed impaired disease-free and OS. The mGPS has been evaluated as a prognostic parameter in accordance with findings in various malignancies.(32) Serum CRP levels, which are identified by activation of proinflammatory cytokines, might lead to tumor invasion, progression, and formation of metastases.(33) Most studies have shown a possible relationship between a chronic, systemic inflammatory response, compromised cellular immune response (34), and tumor cachexia (35), caused by low serum albumin.
Another aspect of our study is that the presenting site of metastasis was associated with the outcome of anti-PD-1 antibody treatment; liver metastasis (HR = 3.093, 95% CI: [1.017–9.405]; p = 0.047) was an independent prognostic indicator of shorter PFS. As we know, the liver has an immunologic organ interplay between immune tolerance and immune activation, which provides for the development of novel therapeutic strategies for cancer.(36) Kupfer cells, liver sinusoidal endothelial cells, dendritic cells play important roles in reducing the immune response and maintenance of immune-suppressive status.(37) The poor response and shorter PFS to anti-PD-1 antibody treatment in patients with liver metastases could be explained by the maintenance of immunotolerance.
In daily clinical practice, oncologists expect to quickly determine the treatment response because lung cancer usually develops extremely progressively in this state. The measurement of serum inflammatory parameters is noninvasive and inexpensive in the assessment of the efficacy of immunotherapy treatment in patients with lung cancer. Quickly rising inflammatory markers may be related to primary refractory disease, indicating a poorer prognosis. If posttreatment 6th-week NLR, PLR, LIPI, and mGPS ratio tend to reduce, this may reassure the physician that they are on the right track to directing the response and better survival.