The Role of the Vagus Nerve in Cancer Prognosis: A Systematic and a Comprehensive Review

Table 1

Summary of available studies of HRV and cancer. SDNN=standard deviation of normal to normal R-R intervals).

Study	Design	Sample size	Cancer type	ECG duration	Controlled for confounders	Cardiac patients included?	Results SDNN	QOL 1-6
Hoffmann 2001	Prospective	35, both genders	Metastatic Carcinoid syndrome; (CS)	24-hour Holter	No	No	SDNN > 100 + CS Predicted mortality	3
Kim 2010	Prospective	68, both genders	All types of primary tumours	5 minute	Yes, full	No	SDNN predicted Duration of survival	4
Fadul 2010	Historical; Prospective	47, males	All types of advanced disease (lung and gastro)	20 minute	No	Yes	SDNN tended to predict survival	2
Chiang 2010	Prospective	33, both genders	Terminal Hepatocellular carcinoma	5 minute	No	Yes	HF-HRV correlate with time-till death	4
Mouton 2012	Historical; Prospective	38, both genders	Colorectal cancer	10 seconds	Yes, full	No	SDNN predicted levels of CEA over 12 monts	4
De Couck 2013	Historical; Prospective	113, male; 133, both genders	Prostate cancer; Non-small cell lung cancer	10 seconds	Yes, full	No	SDNN predicted PSA and survival time in lung cancer in < 65 years	4
Chiang 2013	Prospective	138, both genders	Liver, colon, stomach, head & neck, pancreatic, genitourinary, oesophagal	5min	Yes, partial	Yes	HF-HRV predicted risk of survival < 7 days	4
Wang 2013	Prospective	40, both genders	Lung, breast & others with brain metastases	5min	Yes, full	No	SDNN predicted survival	6
De Couck 2016	Historical Prospective	272, both genders	Advanced pancreatic cancer	10 seconds	Yes, full	Yes, but this variable was controlled for	High SDNN; Predicted; Double survival	4
Kim 2015	Prospective	167, both genders	Advanced non-small-cell lung cancer				SDNN predicted survival	6
Giese-Davis 2015	Prospective	87, only women	Metastatic-recurrent breast cancer	ECG 5min	Yes, partial	Yes	SDNN and SDNN/HR predicted survival	3
Guo 2015	Historical prospective	651, both genders	Several cancers	ECG, 20-24 hours	Yes, partial		SDNN < 70ms predicted shorter survival	4