For NSCLC that progresses after the first and secondary standard treatment, the current change in targeted drugs or chemotherapy regimens and multi-drug combination therapy are commonly used, but the results are still unsatisfactory. Patients with severe adverse reactions, such as severe immune-associated pneumonia, severe liver function injury, and severe bone marrow suppression, during systemic therapy in the first and second lines of treatment, may have poor compliance with systemic therapy in subsequent lines of treatment. The failure of first - and second-line treatments further reduces patient compliance with post-line treatment. This retrospective study of 32 patients suggests that D-BACE plus BAIC is a safe and effective treatment for refractory advanced NSCLC, with no major complications. Tumor control, defined as the achievement of CR, PR, or SD, was successfully achieved in all cases within this series. Furthermore, the median OS in this study was 14.0 months, which appears to be better than that achieved with gemcitabine plus carboplatin (10.0 months), pemetrexed (7.4months), or docetaxel (10.0months) 14, 15. We also found that patients who had previously received immunotherapy had a better tumor response than those who had not. Our results add to the growing body of literature, suggesting that D-BACE plus BAIC is a promising treatment option and may provide a reasonable alternative for refractory advanced NSCLC.
For the management of NSCLC, D-BACE plus BAIC offers two important advantages over systemic chemotherapy. First, the lesions in refractory advanced NSCLC are usually large, leading to blood circulation disorders in the tumor. As such, it is difficult to reach the tumor and its center through an intravenous drip, let alone the effective drug concentration, resulting in poor systemic efficacy and high toxicity16. The administration of transarterial chemoembolization and infusion chemotherapy leads to high concentrations of drugs within the tumor tissue, which can effectively overcome chemoresistance 3. Second, drug-eluting beads have the capacity to embolize the arteries that supply nutrients to tumors, thereby depriving the tumor of its vital source. Additionally, these specialized beads gradually release the chemotherapy drugs, they are loaded with, over the course of a month, ensuring a sustained and controlled delivery of medication directly into the tumor tissue. As a result, the concentration of drugs in the peripheral blood remains minimal. Therefore, the incidence of adverse reactions caused by chemotherapeutic drugs in D-BACE plus BAIC is lower than that in systemic chemotherapy. The theoretical basis for selecting lobaplatin as an arterial infusion chemotherapy drug is as follows: 1) Although cisplatin, carboplatin, nedaplatin and other platinum-based chemotherapy drugs are commonly used in the clinic of non-small cell lung cancer, the patients in this study have been resistant to these drugs, so the efficacy of using these drugs after arterial infusion chemotherapy is expected to be poor, and lobaplatin does not have cross-resistance with the first-and second-generation platinum-based drugs mentioned above. 2) Lobaplatin, as a third-generation platinum, has lower toxic side effects than first-generation platinum, and has shown good anti-tumor effects on non-small cell lung cancer in previous animal experiments and clinical studies17, 18. 3) Compared with oxaliplatin, lobaplatin has better water solubility, and the pH value of its water soluble is 6–8, which is close to the normal physiological pH of human body, so it is more suitable for arterial perfusion chemotherapy, which will not cause arterial irritant spasm. Liu et al. conducted a study that revealed the superior outcomes of D-BACE in terms of PFS and OS when compared to chemotherapy for patients with refractory advanced NSCLC. This study indicates that D-BACE has the potential to serve as an additional treatment option due to its favorable therapeutic efficacy, ability to enhance quality of life, and its tolerable safety profile for these patients 1. He et al. conducted a comprehensive analysis on the effectiveness and safety of D-BACE in comparison to that of BAIC, followed by polyvinyl alcohol (PVA) particle embolization, for treating advanced squamous cell lung cancer after the failure of systemic therapy. The study revealed that the D-BACE group demonstrated a median PFS of 4.3 months and OS of 12.6 months. In contrast, the BAIC plus PVA group exhibited a significantly shorter median PFS of 3.2 months and OS of 8.1 months. These results unequivocally indicate the superiority of D-BACE over BAIC plus PVA embolization in the treatment of advanced squamous cell lung cancer 19. The median PFS and OS in the D-BACE group were shorter than those observed in our study. This may be because BAIC was not performed in the D-BACE group, and squamous cancer accounted for 59.4% (n = 19) of the patients in our study. According to a multicenter prospective study, the use of D-BACE resulted in a notable enhancement in the quality of life for patients with refractory NSCLC. Additionally, the study revealed a median OS of 11.5 months when utilizing this treatment approach 20. However, it should be noted that squamous cancer accounted for 83.7% (36) of the patients in this prospective study, which might have influenced the observed OS. The study reported promising efficacy with a median PFS of 7.0–11.0 months and OS of 8.0–18.4 months, as well as tolerable toxicity in patients with refractory advanced NSCLC (6, 19–21). The PFS and OS rates in these studies were better than those in our study. We suggest that the reason for this difference could be attributed to the fact that only 56.3% (18/32) of patients received systemic therapies in our study. However, patients who received subsequent systemic therapies had higher OS than those without, as shown in the univariate analysis, although subsequent systemic therapies were not identified as an independent influencing factor in the multivariate analysis. These findings suggest that combination therapy may benefit some patients.
In this study, minor adverse events after D-BACE plus BAIC, such as transient chest pain, nausea, vomiting, fever, and fatigue, were usually self-limiting or resolved after conservative symptomatic therapies, which is consistent with previous studies 8, 20. Major complications such as esophageal fistula, spinal cord infarction, posterior circulation cerebral infarction, and myocardial infarction due to non-target embolization were not observed in our study, and were also rare in a recent bronchial artery embolization series 5, 21. However, these serious complications should be noted and avoided, with careful monitoring during the procedure. Based on our experience, the following points may help reduce the complications of the operation: iodized oil should be avoided for embolization of lung cancer because the small diameter of iodized oil droplets can easily cause ectopic embolization, which can further lead to serious complications, such as spinal cord injury and cerebral infarction 20. Drug-eluting beads or microsphere embolization with an inner diameter ranging between 300 and 500 mm is strongly advised based on an in-depth anatomical study. This study proposes that the anastomotic diameter of both the bronchial and pulmonary arteries could potentially accommodate sizes of up to 325 mm 22. An additional factor to consider is that when using an excessively large embolization material, it primarily leads to proximal embolization. This, in turn, significantly diminishes the effectiveness of the treatment due to the establishment of collateral circulation 20. Drug-eluting beads or blank microspheres were utilized in all patients due to their superior size, uniformity, and improved penetration characteristics compared to those of PVA or gelatin sponge particles. Notably, these microspheres possess smooth hydrophilic-coated surfaces, which significantly reduce the risk of clumping within catheters 21. These results indicate that regurgitation does not occur more easily with drug-eluting beads or blank microspheres than with PVA or gelatin sponge particles. As clumping increases the transient resistance to embolic injection, systemic pulmonary shunts should be identified, and a suitable particle embolic agent of particle size should be selected to seal the fistula before D-BACE. Vascular variation or abnormal anastomosis should also be recognized, especially if the tumor-feeding vessels originate from the subclavian artery branches or have anastomotic branches, because ectopic embolization may cause posterior circulation stroke. In addition, blood vessels that communicate with the coronary arteries should also be considered when embolizing, because ectopic embolization may cause myocardial infarction.
The limitations of this study are predominantly associated with the limited sample size and the absence of a control group. In addition, there was heterogeneity in the standard systemic therapies given to patients included in this study; it is difficult to assess the potential effect. Additionally, it is still unknown which chemotherapeutic agents loaded with eluting beads are the most effective and safe in treating NSCLC. A multicenter prospective study had showed drug-eluting beads loaded with epirubicin for D-BACE was effective and safe in treating refractory NSCLC20. In this study, we also used epirubicin for loading DC Bead™ particles, while oxaliplatin, vinorelbine, and gemcitabine have been reported for loading CalliSpheres beads, which are commonly used for lung cancer in systemic chemotherapy 23–25. However, these drugs are not available for being loaded onto DC Beads according to the manufacturer’s instructions. Moreover, we found a correlation between previous immunotherapy and tumor response after treatment. However, due to the retrospective nature of this study, conducting an in-depth analysis was difficult, and we could not provide a convincing explanation. Further studies on immune status and treatment response are expected to answer this question. Finally, only 31.2% of the patients underwent more than three sessions of D-TACE, which may be insufficient to achieve satisfactory efficacy.
D-BACE combined with BAIC is a feasible, safe, and effective treatment option for patients with refractory advanced NSCLC. We present our experience using this technique for patient selection and demonstrate its feasibility with a satisfactory safety profile.