Five studies that compared breast cancer risk between ever-users (current or past use) of COCs and never-users of COCs reported no association between ever use of COCs and breast cancer risk, with effect estimates ranging from 0.90 - 1.12 (Figure 1).
Three studies compared breast cancer risk between current or recent COC users (<6 months since last use) and never users of COCs (Figure 1). One of these studies reported no association between breast cancer risk and COC use. The other two studies found an increased relative risk of 1.19 - 1.33 with current or recent use. Both of these studies found an increased risk of breast cancer with current use of longer duration, with relative risks ranging from 1.03 with less than one year of COC use to approximately 1.4 with more than 8-10 years of COC use.
Figure 1. Relevant Studies of Risk of Breast Cancer with Combined Oral Contraceptives
Figure 1. Relevant Studies Of Risk Of Breast Cancer With Combined Oral Contraceptives (Figure 1)
RR = relative risk; OR = odds ratio; HR = hazard ratio. "ever COC" are females with current or past COC use; "never COC use" are females that never used COCs.
The following additional adverse drug reactions have been reported from worldwide postmarketing experience with levonorgestrel 0.1 mg and ethinyl estradiol 0.02 mg tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Cardiac disorder: chest pain, dyspnea, palpitations
Gastrointestinal disorders: abdominal pain, nausea, vomiting, diarrhea
General disorders and administration site conditions: chest pain, fatigue, pain, malaise, injection site pain or erythema, feeling abnormal, pyrexia, condition aggravated, asthenia
Immune system disorders: hypersensitivity reactions, including pruritus, rash, urticaria, erythema
Injury, poisoning, and procedural complications: injury
Investigations: weight decreased
Musculoskeletal and connective tissue disorders: pain in extremity, arthralgia, back pain, muscle spasm
Nervous system disorders: headache, migraine, dizziness, hypoesthesia, paresthesia
Psychiatric disorders: depression, insomnia, anxiety
Reproductive system and breast disorders: metrorrhagia, menorrhagia, hot flush, vaginal hemorrhage
Respiratory, thoracic, and mediastinal disorders: nasopharyngitis, cough
Sleep disorders and disturbances: somnolence
Vascular disorders: deep vein thrombosis, pulmonary embolism