The rising incidence of LC underscores the pressing need for more effective treatment strategies. Cryoablation has emerged as a promising approach for various cancers, including non-small-cell lung cancer (NSCLC) [11,12,24]. A recent meta-analysis by Xu et al. (2023) found that cryoablation for the treatment of NSCLC was superior to radiofrequency ablation, with improved disease-free survival time, along with fewer complications and a significant reduction in recurrence rates [6]. While effective, an understanding of the MLT is necessary to assure that lung cancer destruction remains unknown. Several clinical studies have suggested an MLT in the −20 °C to −35 °C range [24,25,26]. Accordingly, in this study we utilized the A549 cell line as a model to investigate the response of lung adenocarcinoma carcinoma cells to freezing in an effort to identify the MLT. Additionally, we investigated the effect of combining cryoablation with gemcitabine, a standard chemotherapy drug as a potential adjunctive treatment path for NSCLC.
Understanding the MLT is crucial for optimizing cryoablation protocols. While previous studies have investigated MLT for various cancers, defining it for LC remains open due to the complex nature of lung tissue and varying responses to freezing. The results of this study demonstrate that A549 cells were effectively destroyed following a: single freeze ≤−25 °C; repeat freeze to −25 °C; combination treatment with a single freeze ≤−20 °C; and combination treatment with a repeat freeze ≤−15 °C (Figure 1 and Figure 3). Our reported lethal temperature of −25 °C for a repeat 5 min freeze is comparable to other published data [24] as well as other cancer types, which range from −20 °C to −40 °C [18,19,21,33,58]. Further, studies have shown that translation of the MLT as determined in in vitro studies translates well into in vivo application. For instance, Snyder et al.