Mnemonic to help you remember this is Other BENEFITS.
OC pills decrease the risk of
Other- Ovarian cyst
B– Benign breast disease
E– Ectopic pregnancy
N– Neoplasm (ovarian, endometrial, colon)
E– Endometriosis
F– Fibroid
I– Iron deficiency anemia
T– Tension (premenstrual tension syndrome)
S– Skeletal (Rheumatoid arthritis and osteoporosis)
Hope this helped!