Hormone replacement therapy in menopausal women is linked to endometrial and breast cancers. Based on the data from 1976 to 1992, Harvard University researchers published a report in 1995, which is famous as Nurses’ Health Study. The report concluded that the women, who took oestrogen replacement therapy for 5 years or more, have 40 percent higher risk of developing breast cancer during the age of 55-60 years; The risk of breast cancer among these women was recorded 70 per cent higher during the age of 60 to 65 years.
Roswell Park Cancer Institute in New York conducted a study on 555 mothers who took hormones for infertility in the period, during which they were unknowingly pregnant. This study was published in the American Journal of Epidemiology, which revealed that the children born to these women were having tenfold higher risk of neuroblastoma (a malignant tumour of the embryonic nerve cells) during the first 2 years of life.
Based on a study conducted on 4,212 women, the Science News reported in June 1995 that the women, who took birth control pills before the age of 18 years and continued its use for at least 10 years, have threefold higher risk of breast cancer before the age of 35 years. Another study based on Pap smear study conducted on 1221 pill-user women in comparison to 16,225 non-pill user women has revealed that the pill-user women have 300 per cent higher incidence of cervical dysplasia.
The recombinant Bovine Growth Hormone (rBGH) injections are routinely used in dairy cows to increase the milk yield. The use of dairy milk from rBGH treated cows can cause cancers of the breast and gastrointestinal tract.