It’s time to depolarise the unhelpful PSA-testing debate and put into practice lessons from the two major international screening trials

Authors: James W Denham, Ron Bender and William E J Paradice

Med J Aust 2010; 192 (11): 655. || doi: 10.5694/j.1326-5377.2010.tb03668.x
Published online: 7 June 2010

Incorrect formula and number of trial subjects in Box: In “It’s time to depolarise the unhelpful PSA-testing debate and put into practice lessons from the two major international screening trials” in the 5 April 2010 issue of the Journal (Med J Aust 2010; 192: 393-396), in the Box, there was an error in the total number of prostate cancers detected in the screening arm of the ERSPC trial and in the formula used to calculate differences between the two arms. The Box, with corrected figures in the last two columns and a replacement formula in a footnote, is reproduced here.

Staging and prostate cancer deaths among men participating in the PLCO and ERSPC trials5,6

	Control arm	Screening arm
STAGE OF CANCER AT DIAGNOSIS

PLCO Trial	n = 2940	n = 3437	RD (%)*
Stage 1	15 (0.5%)	18 (0.5%)	+ 2.6%
Stage 2	2790 (94.9%)	3297 (95.9%)	+ 1.1%
Stage 3	56 (1.9%)	49 (1.4%)	– 25.2%
Stage 4	79 (2.7%)	73 (2.1%)	– 21.0%

ERSPC	n = 4611	n = 6169	RD (%)*
Stage T1a,b	277 (6.0%)	212 (3.4%)	– 42.8%
Stage T1c	1805 (39.1%)	3477 (56.4%)	+ 44.0%
Stage T2	1320 (28.6%)	1755 (28.4%)	– 0.6%
Stage T3	749 (16.2%)	509 (8.3%)	– 49.2%
Stage T4	156 (3.4%)	67 (1.1%)	– 67.9%
Stage M1	304 (6.6%)	149 (2.4%)	– 63.4%
CAUSE OF DEATH (in men diagnosed with prostate cancer)
PLCO Trial			Rate ratio†
Prostate cancer	82	92	1.11
Other causes‡	225	312	—

ERSPC
Prostate cancer	326	214	0.80
Other causes	ns	ns	ns

ERSPC = European Randomized Study of Screening for Prostate Cancer. ns = not specified. PLCO = Prostate, Lung, Colon and Ovarian. RD = relative difference. * The relative difference is the percentage increase or decrease in cases of a given stage of prostate cancer detected by screening, using the formula RD = {[(proportion in screened arm ÷ proportion in control arm) × 100] – 100}%. eg, for the PLCO Trial, Stage 3, RD = {[(49/3437 ÷ 56/2940) × 100] – 100}% = –25.2%. † Rate ratio = adjusted value given by the authors.5,6 ‡ Men with prostate cancer dying of other causes.

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