For all other women, using OCs is clearly safer than childbearing in both developing and developed countries. Resolving Uncertainties Even some of the most persistent uncertainties concerning OCs are now coming into perspective. Research suggests that OCs may somewhat speed up the diagnosis of already existing breast cancers perhaps because tumors are more readily detected, tumor growth is accelerated, or both. OC use does not increase lifetime risk of developing breast cancer. Among women who use OCs when young and breast cancer is rare, few additional diagnoses of breast cancer would be due to OCs.
Cervical cancer is even harder to study than breast cancer.
Condoms and careful choice of a sex partner offer the sexually active woman the best protection from human papillomavirus, the primary cause of cervical cancer. This has long been known, but only recently has the word spread. Now OC tablets are being packaged as emergency contraceptive pills, and levonorgestrel-only tablets, which are more effective and cause less nausea and vomiting, are being introduced especially for this purpose. While not as effective as regular use of OCs or most other modern methods, emergency contraceptive pills meet a crucial need another important benefit of one of the world's most widely used family planning methods.