Can dogs smell lung cancer? First study using exhaled breath and urine screening in unselected patients with suspected lung cancer

Figures & data

Figure 1. Olfactory test showing the different dogs’ marking behaviour. Shown is a plank or roundel containing a random order of positive (tumour) and negative samples (no tumour). A, Jippi; B, Fröya; C, Kaos; and D, Tassen.

Table I. Characteristics of the four dogs.

	Kaos	Jippi	Tassen	Fröya
Breed	Belgian shepherd	Border collie	Hard hair dachshund	Rottweiler
Gender	Male	Male	Male	Female
Age (yrs)	8	4	8	3
Previous experience	Scent tracking, missing people, BAD, EP	Scent tracking, EP	Scent tracking	Scent tracking

BAD, behaviour alteration dog; EP, environmental pollutants.

Table II. Characteristics of the malignancy in the study population.

	Malignancy in lung		No malignancy in lung
Parameter	n	%	n	%
Patients (total n = 93)	63	67.7	30	32.3
Patients with LC	59	63.4
NSCLC	40	67.8
SCLC	13	22.0
Carcinoid	2	3.4
Unconfirmed (LC)	3	5.1
Mesothelioma	1	1.7
Lung metastasis (not LC)	4	4.3
Co-cancer	8 (of 59)	13.5	1 (of 30)	3.3
Breast cancer	1	1.7
Colon cancer	1	1.7
Prostate cancer	3	5.1
Urine bladder cancer	1	1.6	1	3.3
Pancreatic cancer	1	1.6
Lip cancer	1	1.6
Clinical stage of LC	59	100.0
Stage I	14	23.7
Stage II	5	8.5
Stage III	17	28.8
Stage IV	23	39.0

LC, lung cancer; NSCLC, non-small cell lung cancer; SCLC, small cell lung cancer.

Table III. Smoking history and concomitant disease in the study population.

	Malignancy in lung		No malignancy in lung
Parameter	n	%	n	%
Smoking history	63	100.0	30	100.0
Never	4	6.3	7	22.6
Former	29	46.0	8	25.8
Current	27	42.9	15	48.4
Not known	3	4.8	1	3.2
Concomitant disease	33 (of 63)	52.4	16 (of 30)	53.3
COPD	17	27.0	7	23.3
CAD	11	17.5	6	20.0
Inflammatory disease	2	3.2	2	6.7
Asthma	0	–	1	3.3
Other	3	4.8	1	3.3
None	30	47.6	19	46.7

CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease.

Table IV. Table showing structured presentation of the specific patient population that was tested with the specific test material along the time course of the study.

Patients (n = 93)	Ordinary training (year 2007)		Intensified training (year 2008)
Patients tested	1st test period	Interim analysis	2nd test period
1–46 (n = 46)	First EBT
47–76 (n = 29)		X
54–93 (n = 40)			Second EBT
	3rd test period (year 2009)
n = 77	Ordinary training		Intensified training
	First UT		Second UT

EBT, exhaled breath test; UT, urine test.

Table V. Table summarizing all olfactory test results: First exhaled breath test (First EBT) and detection of lung cancer after basic training: results for each dog and overall results for the first 46 patients. Second exhaled breath test (Second EBT) and detection of lung cancer after intensified training: the last 40 patients. First and second urine test (First UT and Second UT) and detection of lung cancer after basic training and intensified training, respectively: results of samples for 77 patients.

	Kaos	Jippi	Tassen	Fröya	Overall
First EBT
Sensitivity (%)	67.6	61.8	67.6		64.7
Specificity (%)	16.7	8.3	16.7		8.3
Second EBT
Sensitivity (%)	76.0	64.0		56.0	56.0
Specificity (%)	33.3	33.3		53.3	33.3
First UT
Sensitivity (%)	66.0	69.8		64.2	73.6
Specificity (%)	41.7	29.2		20.8	25.0
Second UT
Sensitivity (%)	49.1	64.2		71.7	64.2
Specificity (%)	33.3	37.5		20.8	29.2