This is a great summary document, but there is something very misleading in it. If you simply count the boxes with X's in them versus the studies that are blank you get the following tally:
Prostate cancer
10 positive studies
3 negative studies
CFS
6 positive studies
8 negative studies
But if you look more closely, it is apparent that 5 of the positive prostate cancer studies do not show any association with XMRV and prostate cancer at all. These are listed below. It is very troubling that these 5 are marked with an 'X' which the summary document equates to a "positive finding". Clearly in this context "positive" only means they found any XMRV at all, but this is not made clear in the heading of the document or the note that says what the 'X' means.
According to my corrected tally, the correct figures representing disease association should read as follows:
Prostate cancer:
5 positive studies
8 negative studies
CFS:
6 positive studies
8 negative studies
Prostate studies that show no association with prostate cancer and are misleadingly marked with an 'X' in the FDA document:
1. Fischer et al, Prevalence of human gammaretrovirus XMRV in sporadic prostate cancer. J Clin Virol. 2008; 43:227-283. They find 1/87 prostate cancer patients (1/105 samples) positive for XMRV and 1/70 controls positive.
2. Switzer et al CDC Paper #149, Abstract 17th CROI meeting, 2010
http://www.retroconference.org/2010/Abstracts/37160.htm. They found low association in prostate cancer with 2/162 (1.2%) positive. There were no controls, but you dont have to be Einstein to work out even if there were that a 1.2% finding is unlikely to show a statistically significant association with prostate cancer.
3. Ikeda Y, et al. Prevalence of XMRV in prostate cancer patients at Mayo clinic. Abstract. International Workshop XMRV. 2010. Reviews in Antiviral Therapy, Volume 8, 2010. This study states in the conclusion of the abstract, "no statistically significant association was observed between the presence of XMRV DNA and prostate cancer"
4. Makarova N, et al. Prevalence of neutralizing antibodies against XMRV in clinical prostate cancer. Abstract. International Worskshop XMRV. 2010. Reviews in Antiviral Therapy, Volume 8, 2010. This one found 6% of prostate cancer cases positive in an antibody test but there were no controls, so it is not evidence of any association given that other studies have had control figures at around this percentage.
5. Fischer N, et al. XMRV prevlaence in prostate cancer tissue and the role of the prostate compartment in XMRV. Abstract. International Worskshop XMRV. 2010. Reviews in Antiviral Therapy, Volume 8, 2010. This one fount XMRV positives in 2/355 samples (0.6%), 0/70 controls and 0/40 blood samples from PC patients.