Generally agree with @Malvolio's answer, though to expand on a claim within the article as requested:
"a strong correlation to calcium consumption and an increased risk of prostate cancer, unproportionally affecting African men. Furthermore, both black children and adults generally secrete less calcium on a daily basis than white people, making them less dependent upon milk"
To support this, the article cites Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies (2014), which claims in its abstract:
Dairy product and calcium intakes have been associated with increased prostate cancer risk, but whether specific dairy products or calcium sources are associated with risk is unclear.
From the conclusions of that article (emphasis added):
In conclusion, we showed increased risk of prostate cancer with intakes of total dairy, milk, cheese, low fat and skim milk combined, total calcium, dietary calcium, and dairy calcium but no association with supplemental calcium or nondairy calcium and an inverse association for whole milk. A positive association between supplemental calcium and fatal prostate cancer needs additional study. Diverging results for types of dairy products and sources of calcium suggest that other components of dairy than fat and calcium may increase prostate cancer risk. Additional prospective studies are needed on types of dairy products and various sources of calcium in relation to risk of subtypes of prostate cancer and, in particular, advanced and fatal cancers.
So, the claim that the calcium in milk causes prostate cancer doesn't appear to be supported by the article's cited study. Rather, the cited study claims:
Increased whole milk consumption correlated with a lower rate of prostate cancer.
Calcium intake does not appear to increase prostate cancer risk.
Abstract 1777: Prostate cancer risk factor profiles in black and white men in the NIH-AARP Diet and Health Study is an abstract for a talk presented at the 2016 conference for the American Association of Cancer Research.
In this talk, the researchers discussed how nutrition may relate to differing rates of prostate cancer in non-Hispanic white men and black men. Their primary point appears to be that the factors that may contribute to prostate cancer may differ between whites and blacks.
Conclusions: Our data suggest that many factors thought to influence prostate cancer risk in predominantly non-Hispanic white populations explain only a small proportion of black male risk, or the black-white difference in risk. Dietary vitamin D intake, height, and alcohol consumption associations with prostate cancer risk may vary between black and white men.
This abstract doesn't mention calcium, though it does mention Vitamin D, also found in milk. Apparently the researchers found that Vitamin D may increase cancer risk for white men, but may decrease cancer risk for black men.
I'd stress that these correlations are highly speculative. For example, the 95% confidence intervals (CI) for Vitamin D's effect for blacks/whites overlaps. So, we're talking about very small, quite-possibly-non-existent effects.
But, if you take the numbers at face value, then Vitamin D may reduce prostate cancer risk in black men. This would seem to suggest that milk's less likely to cause cancer for black men than for white men, all else equal and, again, noting how incredibly small and dubious these alleged effects are.