The study involved 200 rats, half female, split into 10 groups.
As I understand it, the greatest 'statistical significance' comes from the female rats.
Taking one part, and closely analysing it.
'Up to 14 months, no animals in the control groups showed any signs of tumors whilst 10–30% of treated females per group developed tumors, with the exception of one group (33% GMO + R). By the beginning of the 24th month, 50–80% of female animals had developed tumors in all treated groups, with up to 3 tumors per animal, whereas only 30% of controls were affected.'
Starting with the first statement. 'up to 14 months, 1-3 rats in some of the groups developed tumors, whereas no rats in the control group or the group fed GMO + roundup did' So, of 7 groups, 2 groups were cancer free.
Going onto the next part.
3 rats got cancer in the control group.
5-8 in the other 6 groups.
But, half of those 6 groups were also fed roundup.
So, a total of between 9 and 15 extra rats got cancer, apparantly, if you multiply up the control group.
But - the whole basis of this paper now rests on two rats.
If in the control group at the 24th month, 5 rats would normally have gotten cancer, and 2 happened to get lucky, the paper largely becomes non-statistically significant.
I am not a statistician.
If normally, half of rats get cancer at 24 months, then you would expect 5 rats, not 3 in the control group to have it.
How likely is it that only three rats would die?
Only if this chance is under 5% does the rest of the paper have any weight whatsoever.