On Doctoring MEDLINE searches, with reference librarian comments

The question was

Fluoride use and cancer incidence

1 :  exp Neoplasms/         {433674}
2 :  limit 1 to (local holdings and english language)         {256515}
3 :  exp fluorides/ or exp fluorides, topical/         {4640}
4 :  1 and 3         {147}
5 :  limit 4 to (local holdings and english language)         {103}
6 :  limit 5 to review articles         {6}
7 :  limit 5 to (infant < 1 to 23 months > or preschool child <         {5}
2 to 5 years > or child < 6 to 12 years > or adolescence <
13 to 18 years >)
8 :  from 7 keep 1-2         {2}
9 :  from 7 keep 1-2         {2}
10 :  1 and 3         {147}
11 :  limit 10 to (infant < 1 to 23 months > or preschool child <         {10}
2 to 5 years > or child < 6 to 12 years > or adolescence <
13 to 18 years >)

Reference Librarian comments

You did a fine job. Congratulations. Just for fun, I went to
Medline and took an entirely different approach. I decided to forget
the "neoplasms" angle (which always worries me, because there are
other terms I'm never sure will be included, like "chromosomal
aberrations," "teratogenicity," etc. etc.). Anyway, I decided to
look for bad effects of Fluorides, linked to Public Health, and then
just look through those. Some will be about mottled teeth in
children, and some will be "cancer."

My search is not "better" than yours, just a different angle...

Here's what I did:

1 : 
exp *Fluorides/ae,to [Adverse Effects, Toxicity]
254

2 : 
exp Public health/
864699

3 : 
1 and 2
112

4 : 
limit 3 to (human and english language)
84