Gemlin said...
BillyBob - no consensus among scientists (as always).
Diabetes gives protection against prostate cancer as this study reports.
Diabetes mellitus and prostate cancer risk; a nationwide case-control study within PCBaSe Sweden.
Somebody said...
BACKGROUND:
Diabetes mellitus (DM) increases the risk for cancer at almost all sites, but data on the association with prostate cancer are inconsistent.
METHODS:
We assessed the risk of a prostate cancer diagnosis among men with type 2 (T2)DM in a nationwide population-based case-control study including 44,352 men with prostate cancer identified through the Prostate Cancer data Base Sweden (PCBaSe) between 2002 and 2006 and 221,495 age-matched men from the general population.
CONCLUSIONS:
This nationwide study confirmed a reduced risk of being diagnosed with prostate cancer among men with T2DM (type 2 Diabetes mellitus), especially for low-risk tumors.
Gemlin, I have been looking through the free full report on that study, and as often happens the details raise some questions for me, or at the least there are some interesting things in there. For one thing, the overall risk reduction of 20% for diabetic men was actually 71% for the low risk tumors, meaning there had to be less risk reduction for the higher risk men in order to lower the overall result to only 20%.
For example, the men with PC AND diabetes actually had about
a 10% higher chance of having T3-4 tumors than the men with out diabetes( hopefully I have not made a math error, but the men with diabetes had a 27.6% chance of T3-T4, while the men without only had 25%)
The diabetic men also had a higher risk of mets and about
a 20% greater risk of PSA > 100, and a higher risk of being, like me, G8-10. The title of the study I linked to( Diabetes mellitus is associated with elevated risk of mortality amongst patients with prostate cancer: ) now makes more sense, and maybe does not even conflict with the study you linked? But it also makes me wonder why the take away from that study is "This nationwide study confirmed a reduced risk of being diagnosed with prostate cancer among men with T2DM (type 2 Diabetes mellitus), especially for low-risk tumors. ", when even their study still seems to show you are more likely to die from PC if you are diabetic? That seems the far more important take away to me. Am I just crazy?
Also, I notice that the longer they had diabetes, and the more aggressive their treatment, the lower their odds of being diagnosed with PC. Which makes one wonder: is it the diabetes that is protective of low risk disease, or the treatment? ( think Metformin ). Here are a couple of other interesting quotes from the study:
Somebody said...
A slightly higher proportion of men with prostate cancer were married and belonged to a higher socioeconomic category than among the controls.(Uh OH! LOL! )..........
Prostate cancer cases with T2DM tended to have a more adverse risk profile at the date of diagnosis than cases without T2DM; there was a higher proportion of cases with advanced local disease T3,4 tumors (27.6% vs. 25%), a higher proportion of poorly differentiated tumors, Gleason score 8–10 (25.7% vs. 19.3%), and metastatic disease (24.3% vs. 21%)..............
Overall, there was a 20% reduced risk of being diagnosed with prostate cancer among men with T2DM compared with men without (Table 3). We observed a continuous trend of decreasing prostate cancer risk with increasing time since diagnosis of diabetes; among men who were diagnosed 20 years or more before their prostate cancer, the risk was reduced by 35%. On average, this represents a 1% reduced risk per year with diabetes (OR, 0.989; 95% CI, 0.983–0.995). There was a lower risk of prostate cancer both among users of oral hypoglycemic agents (OHA) and insulin than among men without these drugs. However, “diet only” also conferred a modest but statistically significant risk reduction.
So, have I got this right? Diabetes decreases you risk of PC, but
fixing diabetes with treatment(or even just diet) decreases your risk even more? How odd. And the longer you have had it and thus the longer you have been treated, the better your odds, at lest for the low risk guys. Wow, interesting. But it does seem that for us high risk guys, best still to limit the sugar and the diabetes some think comes from too much sugar.
Somebody said...
The Health Professionals Follow-up study reported an inverse association between T2DM and prostate cancer both among cases of localized and advanced-stage prostate cancer in the pre-PSA era, but no association with advanced-stage tumors in the PSA era (12). The uptake of PSA testing has been slower and less pronounced in Sweden in comparison to the United States. It has been estimated that in 2007, 56% of Swedish men 55–69 years of age had undergone at least one PSA test (23).
Detection of prostate cancer among men with T2DM
Speculatively, differences in the mode of detection of prostate cancer could explain the inverse association between T2DM and prostate cancer. Diabetic (24–26) and obese men (27–29) have lower levels of PSA than healthy men. Therefore, men with T2DM and obesity may be less likely to be diagnosed with prostate cancer initiated by an elevated PSA level. Also, less PSA testing has been reported among men with T2DM (21, 30, 31) and overweight (21, 30, 31) than among healthy men. Accordingly, in the REDUCE trial, where all study participants underwent prostate biopsy regardless of serum PSA, no association between T2DM and prostate cancer risk was observed (32). Our findings of higher age and more advanced tumors among men with T2DM and prostate cancer could thus indicate that selection may contribute to the observed inverse association between T2DM and prostate cancer. Differences in marital status and social class may point in the same direction.
Ah, once again, the risk of selection bias rears it's ugly head. I don't know if that is the case or not, but it seems even they think it is possible. In the meantime, the important take away seems to be- in their conclusion- that diabetes is protective against PC, but not other cancers. I'm not sure I agree with them about
that, but I do wish they would figure it out for sure and let us know! ;)
Post Edited (BillyBob@388) : 1/29/2017 2:31:05 PM (GMT-7)