Table 2.

Correlation of baseline and post-chemotherapy follow-up parameters with cfDNA detectability

Baseline and post-chemotherapy correlations	Parameters	Spearman coefficient	P value
Correlation of cfDNA detectability at baseline	Gender	–0.12	0.35
	ECOG status	0.19	0.16
	KPS	0.21	0.11
	Smoking status	0.04	0.77
	Smoking severity	–0.09	0.49
	TNM 8 stage	0.18	0.16
	Co-morbidities	0.04	0.76
	RSB score	0.05	0.71
	TSB score	0.05	0.71
	Weight change	–0.08	0.52
Correlation of cfDNA detectability at follow-up (post chemotherapy)	ECOG status	0.00	1.00
	KPS	0.10	0.60
	RSB score	–0.32	0.11
	TSB score	–0.10	0.60
	Weight change	0.10	0.63
	RECIST 1.1 change	–0.02	0.93

cfDNA: cell free DNA; ECOG: Eastern Co-operative Oncology Group; KPS: Karnofsky performance scale; TNM: tumor-nodes-metastasis; RSB: respiratory symptom burden; TSB: total symptom burden