Progestogen only contraception use has not been used as widely and for as long as the combined oral contraceptive pill, which has meant there is less data about the associated risks. However, a recent study has concluded that progestogen only contraception whether as the minipill, implant or IUS, does increase breast cancer risk in levels similar to the COCP.^17,18,19

The researchers said analysis of Clinical Practice Research Datalink (CPRD) figures shows a significant increase in the risk of breast cancer with any hormonal contraception:

• COCP – 23%
• POP – 26%
• Injected progestogen – 25%
• IUS – 32%

The absolute excess risk of developing breast cancer over a 15-year period in women who used oral contraception for five years also increases with age. Five years’ use in women aged 16 to 20 saw a risk of eight in 100,000 women being affected, whereas the figure was 265 in 100,000 for women aged 35 to 39.

However, the data also shows that breast cancer risk associated with oral contraception declines after stopping use.

Other data suggests that the COCP is linked to a slight increase in the risk of cervical cancer (which can return to baseline risk levels 10 years after stopping the COCP), and a sustained reduced risk of ovarian cancer and endometrial (womb) cancer.¹⁷

Data is less robust for POP in terms of ovarian or endometrial cancer, but it could be similar to COCPs in reducing risk.