3.1 General information of the research object
The distribution of general demographic data and clinical information of 1059 lung cancer patients included in this study is shown in Table 1. The median survival time of all subjects was 24.33 months, the minimum age was 23 years, the maximum age was 86 years, and the mean age was 59.0 ± 10.7 years. There were 774 males (73.10%), 285 females (26.90%), and 671 smokers (63.90%). The pathological types were mainly adenocarcinoma, squamous cell carcinoma and small cell lung cancer. 572 cases (54.00%), 297 cases (28.00%) and 85 cases (8.00%), respectively. There were 457 patients (43.20%) in early stage, 602 patients (56.80%) in advanced stage, 552 patients (52.10%) in surgical treatment, 749 patients (70.70%) in chemotherapy, and 208 patients (19.60%) in radiotherapy. By October 11, 2020, there were 1045 cases of effective follow-up, with a follow-up rate of 98.7%, 14 cases of lost visitors, with a follow-up rate of 1.3%, 227 cases of survival (21.4%), and 818 cases of death (77.2%).
Table 1
Basic information distribution table of lung cancer patients
Variable | Variable | Number of cases(n = 1059) | Constituent ratio(%) |
Sex | male | 774 | 73.10 |
| female | 285 | 26.90 |
Age | ༜60 | 527 | 49.80 |
| ≥ 60 | 532 | 50.20 |
Smoking | Yes | 671 | 63.90 |
| No | 379 | 36.10 |
Pathological pattern | Adenocarcinoma | 572 | 54.00 |
| Squamous carcinoma | 297 | 28.00 |
| Others | 190 | 18.00 |
Clinical stages | Early stage | 457 | 43.20 |
| Later stage | 602 | 56.80 |
Operation | Yes | 552 | 52.10 |
| No | 507 | 47.90 |
Chemotherapy | Yes | 749 | 70.70 |
| No | 310 | 29.30 |
Radiation oncology | Yes | 208 | 19.60 |
| No | 851 | 80.40 |
3.2 Correlation between gene polymorphism and prognosis of lung cancer
Cox proportional risk model was used to explore the relationship between SNPs and overall survival of lung cancer. Considering that multiple factors may affect the prognosis of lung cancer patients, univariate analysis and multivariate analysis were conducted successively in this part. SNPs and overall survival time were analyzed.
The overall survival of lung cancer with different SNPs genotypes was shown in Table 2. Log-rank test showed that there was no significant difference in overall survival time between different SNPs genotypes (P > 0.05).
We further adopt Cox proportional hazards models to grouping children by age, gender, pathological type, with or without treatment, total stage of adjustment factors, under various genetic model for overall survival analysis of all SNPs, HR was calculated and the corresponding 95% CI, including codominant genetic model model, model of dominant and recessive models and additive model. Results of survival analysis were shown in Table 2. The correlation between SNPs loci and overall survival time in various genetic models was not found to be statistically significant.
Table 2
Results of overall survival analysis of SNPs lung cancer patients
Genetic locus | Genotype | Lung cancer |
Total number/deaths | Log rank P | αHR(95%CI)* |
rs13409 | | | | |
Co-dominance | CC | 396/507 | 0.965 | 1 |
| CT | 292/379 | | 0.948(0.815–1.104) |
| TT | 87/116 | | 0.919(0.728–1.161) |
Dominance | CC | 396/507 | 0.831 | 1 |
| CT + TT | 379/495 | | 0.941(0.817–1.084) |
Recessiveness | CC + CT | 688/886 | 0.819 | 1 |
| TT | 87/116 | | 0.940(0.752–1.177) |
Additivity | | | 0.792 | 0.928(0.735–1.172) |
rs6815391 | | | | |
Co-dominance | TT | 365/473 | 0.541 | 1 |
| CT | 333/433 | | 1.075(0.926–1.249) |
| CC | 78/99 | | 1.180(0.924–1.508) |
Dominance | TT | 365/473 | 0.347 | 1 |
| CC + CT | 411/532 | | 1.094(0.949–1.260) |
Recessiveness | CT + TT | 698/906 | 0.395 | 1 |
| CC | 78/99 | | 1.141(0.902–1.442) |
Additivity | | | 0.292 | 1.169(0.915–1.494) |
rs3740535 | | | | |
Co-dominance | GG | 467/587 | 0.667 | 1 |
| AG | 275/366 | | 0.948(0.816–1.101) |
| AA | 58/74 | | 0.889(0.676–1.169) |
Dominance | GG | 467/587 | 0.371 | 1 |
| AA + AG | 333/440 | | 0.937(0.814–1.079) |
Recessiveness | AG + GG | 742/953 | 0.846 | 1 |
| AA | 58/74 | | 0.907(0.694–1.186) |
Additivity | | | 0.721 | 0.895(0.680–1.177) |
rs3130932 | | | | |
Co-dominance | TT | 350/442 | 0.497 | 1 |
| GT | 101/451 | | 0.959(0.827–1.113) |
| GG | 92/129 | | 0.804(0.638–1.013) |
Dominance | TT | 350/442 | 0.299 | 1 |
| GG + GT | 440/580 | | 0.923(0.802–1.062) |
Recessiveness | GT + TT | 698/893 | 0.382 | 1 |
| GG | 92/129 | | 0.821(0.660–1.022) |
Additivity | | | 0.285 | 0.810(0.643–1.022) |
Note: * Adjusting factors were age, sex, pathological type, presence or absence of treatment, and total stage |
3.3 Stratified analysis of SNPs polymorphism and prognosis of lung cancer
SNPs were divided into three genetic models: dominant, recessive and additive genetic models. In order to explore the effects of SNPs polymorphism changes on patients with different demographic and clinical characteristics, stratified analysis was conducted based on the collected clinical data, as shown in Fig. 1–4.
The results showed that the risk effect of recessive and additional rs3740535 on prognosis was significant in patients with a family history of lung cancer. Among recessive genotypes, the risk of death in patients with rs3740535 AA genotype was 5.210 times higher than that in patients with AG + GG genotype (95%CI:1.273–21.324). Among the additional genotypes, the risk of death in patients with rs3740535 GG genotype was 30.583 times higher than that in patients with AA genotype (95%CI:1.879-497.832). Heterogeneity test showed that there was significant heterogeneity of this risk effect in both recessive and additive genotypes of rs3740535 with or without a family history of lung cancer (Pheterogeneity <0.05). (Fig. 1)
Rs3130932 has both dominant and additive effects on prognosis in patients with hematogenous metastasis. In dominant genotypes, patients with rs3130932 GT + GG genotype had 1.492 times higher risk of death than patients with TT genotype (95%CI:1.094–2.034). Among the additional genotypes, the risk of death in patients with blood type transfer was 1.856 times higher in patients with TT genotype than in patients with GG genotype (95%CI:1.097–3.143). Heterogeneity test showed that the risk effect of rs3130932 had significant heterogeneity between the dominant and additive genotypes with or without subgroups (all Pheterogeneity <0.05). Rs3130932 has a recessive protective effect on the prognosis of patients receiving radiotherapy. Patients with rs3130932 GG genotype had a significantly lower risk of lung cancer death than patients with GT + TT genotype (HR = 0.420, 95%CI:0.217–0.814). Heterogeneity test found that this protective effect was significantly different between radiotherapy subgroups (Pheterogeneity =0.009). (Fig. 2)
The risk effect of rs13409 on prognosis was significant in patients with a family history of lung cancer. The risk of death in patients with rs13409 TT genotype was 190,708.408 times higher than in patients with CC genotype (95%CI:220.699-164793486.900). Heterogeneity test showed that patients with a family history of lung cancer and carrying the rs13409 additional TT genotype had a higher risk of death than patients without a family history of lung cancer, and the risk was statistically significant (Pheterogeneity < 0.01). (Fig. 3)
In patients with pathological types other than adenocarcinoma and squamous cell carcinoma (HR = 1.590,95%CI:1.053–2.401), rs6815391 dominant CT + CC genotype carriers were associated with an increased risk of death, and this risk effect was significantly different between subgroups of pathological types (Pheterogeneity =0.037). Patients with a family history of lung cancer (HR = 0.358,95%CI:0.150–0.852) had a significantly reduced risk of death, and this protective effect was significantly different among the subgroups with and without a family history of lung cancer (Pheterogeneity =0.012). The recessive risk effect of rs6815391 on prognosis was more significant in patients who did not receive chemotherapy. The risk of death was 1.805 times higher in patients with CC genotype than in patients with CT + TT genotype (95%CI:1.115–2.922). Heterogeneity test found that this risk effect was significantly different between subgroups receiving chemotherapy or not (Pheterogeneity =0.027). In patients without chemotherapy (HR = 2.027,95%CI:1.186–3.466) and abnormal BMI (HR = 1.763,95%CI:1.110–2.800), rs6815391 patients with additional TT genotype had a higher risk of death than those with CC genotype. Heterogeneity test found significant heterogeneity between chemotherapy subgroups (Pheterogeneity =0.022) and statistically significant heterogeneity between normal BMI subgroups (Pheterogeneity =0.027) (Fig. 4).
Based on the stratified results, we further analyzed the interaction between different genotypes and factors with heterogeneity among sublayers of clinical variables (Table 3–5), and the results showed that, after adjusting for gender, age, initial diagnosis, pleural metastasis, lymphatic metastasis, hematologic metastasis, BMI, presence or absence of treatment, presence or absence of surgery, maximum tumor size, presence or absence of pulmonary disease, education, smoking history, total stage and other variables:
There were no statistically significant effects of rs3740535 recessive and additive models on the combined effect, multiplicative interaction and additive interaction of rs3740535 and family history of tumor. See Table 3 for details.
Table 3
Analysis of interaction between rs3740535 genotypes and family history of cancer
Implicit model | | Additive model |
Genotype | Family history of cancer | αHR(95%CI)* | | Genotype | Family history of cancer | αHR(95%CI)* |
AG + GG | No | 1 | | AA | No | 1 |
AG + GG | Other tumors | 0.969(0.761–1.234) | | AA | Other tumors | 0.906(0.678–1.210) |
AG + GG | Lung cancer | 1.129(0.810–1.572) | | AA | Lung cancer | 1.179(0.752–1.847) |
AA | No | 0.949(0.669–1.346) | | GG | No | 1.009(0.706–1.443) |
AA | Other tumors | 0.677(0.347–1.321) | | GG | Other tumors | 0.704(0.358–1.385) |
AA | Lung cancer | 2.047(0.744–5.637) | | GG | Lung cancer | 2.130(0.758–5.981) |
Multiplication interaction | | 1.035(0.912–1.175) | | Multiplication interaction | | 1.019(0.873–1.190) |
Relative excess risk(RERI) | | 0.125(-0.434-0.685) | | Relative excess risk(RERI) | | 0.121(-0.434-0.675) |
Attributable risk percent(ARP) | | 0.203(-0.594-1.001) | | Attributable risk percent(ARP) | | 0.207(-0.692-1.106) |
Synergic index(S) | | 0.754(0.172–3.307) | | Synergic index(S) | | 0.775(0.205–2.931) |
Note: * is adjusted for gender, age, first diagnosed metastasis, pleural metastasis, lymphatic metastasis, hematologic metastasis, BMI, whether there is treatment, whether there is surgery, maximum diameter of tumor, whether there is lung disease, education background, smoking history, and total stage (when adjusting factors are included, the corresponding combined items are not included in the adjustment). |
In the dominant model, patients with rs3130932 GT + GG genotype had 1.362 times higher risk of death than patients with rs3130932 TT genotype with hematoascular metastasis (95%CI:1.021–1.818). In recessive model, the risk of death of lung cancer patients carrying rs3130932 GG genotype and receiving radiotherapy was 0.536 times higher than that of lung cancer patients carrying rs3130932 GT + TT genotype and receiving radiotherapy (95%CI:0.298–0.962). Rs3130932 recessive had a significant positive multiplicity interaction with radiotherapy. Patients with rs3130932 GG genotype had 0.650 times higher risk of death than patients with rs3130932 GT + TT genotype (95%CI:0.464–0.911). In the additive model, rs3130932 had no significant combined effect with blood metastasis and gender, but rs3130932 had significant positive multiplying interaction with gender. Rs3130932 polymorphism changes and blood group metastasis in the three models showed significant negative multiplicative interaction, but no significant additive interaction. Table 4 shows this in more detail [see Additional file 1].
In the dominant model of rs6815391, there was no significant association between rs6815391 and family history of tumor. Patients with rs6815391 TT genotype and pathological type other than adenocarcinoma and squamous cell carcinoma had a 0.707 times higher risk of death than patients with rs6815391 TT genotype and pathological type of adenocarcinoma (95%CI:0.512–0.978). Rs6815391 dominance had no significant multiplication and addition interaction with tumor family history and pathological type. In the recessive model, the risk of death in patients without chemotherapy carried by rs6815391 CC genotype was 1.859 times higher than that in patients receiving chemotherapy carried by rs6815391 CT + TT genotype (95%CI:1.165–2.965), but there was no significant interaction between multiplication and addition. In the additive model, the risk of death in patients without chemotherapy carrying rs6815391 TT genotype was 2.062 times higher than that in patients receiving chemotherapy carrying rs6815391 CC genotype (95%CI:1.263–3.366), while there was no significant combined effect between rs6815391 additive subgroup and BMI subgroup. There was no significant multiplicative and additive interaction between rs6815391 additive, chemotherapy and BMI subgroups. Table 5 fshows this in more detail [see Additional file 1].
There was no obvious combined effect between rs13409 and pulmonary disease, but there was negative multiplicative interaction and antagonistic additive interaction. In the additive model, there was no obvious combined and multiplied interaction between rs13409 and lung disease, and the risk of death of patients with rs13409 TT genotype and family history of lung cancer was 3.234 times higher than that of patients with rs13409 CC genotype and no family history of cancer (95%CI:1.138–9.196). There was no significant additive interaction between rs13409 and family history of lung disease and tumor. Table 6 shows this in more detail [see Additional file 1].