Is it useful to combine sputum cytology and low-dose spiral computed tomography for early detection of lung cancer in formerly asbestos-exposed power industry workers?

Table 3 Participants with newly diagnosed lung cancer during the examination period: comparison of sputum cytology with the results of low-dose spiral computed tomography (LDSCT) of the thorax for the whole cohort (n = 187)

	Lung cancer	No lung cancer^a	Total^b
Sputum cytology
Suspicious or pathological^c	7	3	10
Regular or equivocal^d	5	172	177
LDSCT
Suspicious	11	6	17
Regular	1	169	170
Cytology and LDSCT
At least one positive	12	8^e	20
Both negative	0	167	167

^aIncluding six lung cancer patients falling ill outside the examination period.
^bThe totals of test results in each group add up to n = 187.
^cIn at least one sputum sample.
^dIn all samples tested.
^eIn one participant, both results were positive.