Table 1.

Publication Rates of Cancer Trials registered at ClinicalTrials.gov, by Category.

Category	Number of Trials	Percent
		Distribution	Published	Positive^a
All cancer trials^b	2,028	100.0%	17.6%	64.5%

Stage
Completed	1,791	88.3%	19.5%	64.3%
Terminated	237	11.7%	3.4%	75.0%

Randomization
Randomized	490	24.2%	19.6%	60.4%
Non-randomized	572	28.2%	4.4%	90.9%
Not specified	966	47.6%	24.4%	63.6%

Treatment-Type
Drug	1,875	92.5%	17.4%	64.5%
Procedure	970	47.8%	25.7%	60.3%
Other	63	3.1%	19.0%	81.8%

Phase
I	579	28.6%	14.9%	89.9%
II	1,076	53.1%	17.3%	53.6%
III	270	13.3%	26.3%	63.2%
IV	50	2.5%	14.0%	83.3%
Not specified	53	2.6%	13.2%	57.1%

Sponsor-Type^c
University/Research Org.	853	42.1%	14.0%	70.2%
Industry	614	30.3%	5.9%	75.0%
NIH	209	10.3%	27.3%	78.8%
Network	205	10.1%	59.0%	50.0%
Other	147	7.2%	16.3%	65.2%

Registration Date
Before 9/1/04	1,277	63.0%	21.0%	64.0%
9/1/04 – 9/1/07	751	37.0%	11.9%	66.3%

Trial results stated as rejection of the null hypothesis or authors’ conclusions. See text for details. Based on registered trials with published abstracts.

Interventional trials that were either completed or terminated as of 9/1/07.

All sponsor-type categories are as listed by the ClinicalTrials.gov website.

University/Research Organizations are post-secondary institutions of higher learning or research organizations that are affiliated with post-secondary institutions. Networks are international quasi-private medical research facilities.