Recent Japanese XMRV/Prostate Cancer Study

[Andrew]

1274 a Preliminary Screening of Xenotropic Murine Leukemia Virus-related Virus in Japanese Prostate Cancer Patients

Tsukasa Igawa*, Yoshinao Kubo, Katsura Kakoki, Naoki Yamamoto, Hideki Sakai

The Journal of Urology
Volume 185, Issue 4, Supplement , Page e510, April 2011

"Our results suggest relatively lower rate of existence for XMRV in prostatic tissue of Japanese prostate cancer patients. In addition, there also exists a possibility of polytropic MLV infection in Japanese prostate cancer patients, and it may be the first report regarding polytropic MLV gene sequence detection in Japanese male."

http://www.jurology.com/article/S0022-5347(11)01208-0/fulltext

 

[Mark]

I've merged and moved some of these threads on recent XMRV studies - but this one doesn't seem to have a thread of its own yet. If there are any posts or threads elsewhere dealing specifically with this study, please let me know and I'll do some more tidying up.

MLV sequences were detected in four out of sixty one patients (6.7%). Of these four positive cases, XMRV was detected in one. And in the other three cases, polytropic MLV gene sequence was detected. The clinical diagnosis of XMRV positive case was cT2bN0M0, Gleason score 4+4=8, PSA 20.7 ng/ml with no family history for prostate cancer. Subsequently, blood sample from this patient was analyzed, however, XMRV was not detected. Three polytropic MLV detected cases included 2 positive and one negative for prostate cancer.

This may be the first research team to publish results finding both XMRV and the polytropic MLVs.

 

[Andrew]

Yes, they found both. Which means that it's not just Alter who found its existence. But at the same time, it is a negative study with regard to a correlation between prostate cancer and XMRV.

 

[Mark]

Ah, now that's a good point too, they're also the first group after Alter/Lo to report finding the P-MLVs as well!

I wouldn't really characterise it as a negative study though; they didn't find a strong association with PC but the results don't make it clear what the percentages of PC in the samples were; and with such a small sample size there doesn't seem enough data to determine the rate of correlation with PC anyway. Some of the prostate biopsy samples were from prostate cancer patients, some weren't, and of course those without PC may conceivably develop PC later...and the study doesn't seem to state how many there were of each group - so we don't actually know from the data in the study what the correlation was. As far as I'm concerned, any researchers who can detect XMRV and P-MLVs in human samples represents a very positive development, because at the rates they report here, if their findings are valid then all the 0/0 studies must simply be failing to detect.

 

[Andrew]

Now that I look more closely, I see that it's hard to draw any conclusions about how many subjects were cancer free. All they say is 61 samples. We don't know if that equals 61 subjects or if they tested more than one sample from a subject.

They say "Three polytropic MLV detected cases included 2 positive and one negative for prostate cancer." What do they mean by "cases." Do they mean "people" or do they mean "core samples." They also say "The clinical diagnosis of XMRV positive case was cT2bN0M0, Gleason score 4+4=8, PSA 20.7 ng/ml with no family history for prostate cancer. Subsequently, blood sample from this patient was analyzed, however, XMRV was not detected." So this is one example of XMRV infection in body but not detectable by whatever method they used for the blood.

I wish we had more information.