Why cervical cancer is the preventable one · Week 14
High-risk HPV switches off the cell's tumor-suppressor genes. Damaged cells then keep dividing instead of self-destructing. That takes years, and those years are the whole opening for screening. Run the clock and see what each plan catches.
Inside the cervical lining
Cells sit in layers on a basement membrane. Abnormal cells climb from the bottom up. Once they break through the membrane, it is invasive cancer.
Normal cellDysplastic cellInvasive cancer
Set up a case and drag the years.
Twenty years on one line
Gray ticks are screening visits. The flag marks the first visit that would find something.
Year 0A new HPV infection
Set up the case
Which HPV strain?
Screening plan
Years since the infection0
Lining stage
normal
what the cells look like
Abnormal depth
0
% of the layers
Warning window
16
years left before invasion
Screens done
0
visits so far
Caught at
–
year of the first catch
Ends in cancer
0
% on this path · model figure
What is happening now
Set a strain and a plan.
These percentages are a model. They are not one person’s odds. They come from the usual course of severe dysplasia left alone, which turns invasive in about 30 to 50 percent of cases over decades, and from vaccines that block about nine in ten of the strains behind this cancer.
Prevention stacks. The vaccine blocks the infection. Screening finds the pre-cancer that slips past. A normal Pap does not cancel the need for the vaccine, and the vaccine does not cancel the need for screening.