alt Hacker NewsI'm still expecting the cause to be HPV and increase in anal sex. Some studies seem to point that way (and other studies that say it might not), but it hasn't been proven yet. However it would make sense, considering that it leads to cervical cancer, throat cancer, etc.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9610003/
Not an expert on this by any means, just went down this rabbit hole when deciding if I should be asking about my son getting the HPV vaccine when it was first made available to males, and before it was broadly recommended for men.
A rise in meat (esp red & cured meats) consumption and a drop in vegetable consumption would also do it, particularly if it were disproportionately occurring in certain cohorts.
12% of Americans eat half the nation's supply of beef, and members of that group are disproportionately male and disproportionately middle-aged.