Comparisons between tumor burden and other prognostic factors that influence survival of patients with non‐small cell lung cancer treated with immune checkpoint inhibitors

Abstract

Background The use of baseline tumor burden (TB) as a prognostic factor for non‐small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) and associations between TB and other prognostic biomarkers remain unclear. In this study, we investigated the association between TB and survival in NSCLC patients treated with ICIs in comparison with other biomarkers. Methods We retrospectively evaluated 83 NSCLC patients with ICIs administered between February 2016 and December 2018. TB was measured as the sum of the unidimensional diameters of up to five target lesions. Results The median observation period was 14.2 months. A total of 42 patients died during the follow‐up. Univariate Cox regression analysis showed that baseline TB was associated with OS. Cox regression analysis adjusted for Eastern Cooperative Oncology Group performance status (ECOG PS) alone or with addition of programmed cell death ligand 1 expression and treatment line showed that TB was a prognostic factor for OS. Using time‐dependent receiver operating characteristic curve analysis, the optimal TB cutoff for predicting OS was 12 cm, and patients were divided into a high TB group (n = 21) and a low TB group (n = 62). The low TB group achieved significantly longer OS than the high TB group (median OS: 18.5 months, [95% CI = 11.7‐not reached] vs. 2.3 months [95% CI = 1.3–2.9], P < 0.001). Conclusion TB is a useful, clinically measurable prognostic factor of survival in NSCLC patients treated with ICIs.

Factors related to rapid progression of non‐small cell lung cancer in Chinese patients treated using single‐agent immune checkpoint inhibitor treatment

“…Our study also showed that RP was not associated with tumor burden, which is probably because the RECIST v1.1‐defined target lesions do not always truly reflect the entire tumor burden, especially in patients with nonmeasurable disease, such as bone metastases, pleural effusion, or malignant atelectasis. Several studies have also showed that patients with high tumor burden experience poor OS after starting immunotherapy, which suggests that tumor burden may be a prognostic factor rather than a predictor of response …”

Potential of FDG-PET as Prognostic Significance after anti-PD-1 Antibody against Patients with Previously Treated Non-Small Cell Lung Cancer

“…Tumor response was evaluated using the Response Evaluation Criteria in Solid Tumors version 1.1 [17]. Baseline TB was evaluated using CT for target lesions [13,14]. TB was defined as the sum of the longest diameter for a maximum of five target lesions and up to two lesions per organ [13,14].…”

“…In all 85 patients, the median values of SUVmax, MTV, and TLG on 18 F-FDG and TB were 6.0 (range, 3.1-21.0), 17.8 cm 3 (range, 1.1-379 cm 3 ), 75.4 gcm 3 /mL (range, 3.9-2550 g•cm 3 /mL), and 65 cm (range, 6.6-230.6 cm), respectively. According to histological types, the median values of SUVmax, MTV, and TLG on 18 F-FDG and TB in adenocarcinoma were 6.7 (range, 3.1-21.3), 11.3 cm 3 (range, 1.1-276 cm 3 ), 58.3 g•cm 3 /mL (range, 3.9-1398 g•cm 3 /mL), and 53 cm (range, 6.6-230.6 cm), respectively, and those in non-adenocarcinoma displayed 8.4 (range, 3.2-20.4) 24.8 cm 3 (range, 1.1-379 cm 3 The discriminative value of various SUVmax, MTV, and TLG cutoffs for 18 F-FDG uptake were explored in the context of OS and PFS ( Figure 2) [13]. For prognosis in OS and PFS analyses, the most discriminative cutoffs based on log-rank test for SUVmax, MTV, and TLG were 6.0, 5.0, and 20, respectively.…”

“…The SUVmax cutoff of 6 was not significant in either OS or PFS analysis, but still seemed better considering the results of the log-rank test. The 12 cm cutoff for TB was based on a previous study [13]. 4…”

“…Moreover, an exploratory study documented that the tumor metabolic activity assessed by TLG and MTV is better than SUVmax in evaluating the therapeutic monitoring of anti-PD-1 antibody in patients with previously treated NSCLC [10]. Recent reports suggested that baseline tumor size could predict adverse outcomes in patients with NSCLC who received ICI [12][13][14]. However, the detailed mechanism behind tumor burden (TB), determined by baseline tumor size and causing poor efficacy of ICI, is unclear.…”