This is the first study in Palestine that provides clear evidence that late menarche poses an additional risk for breast cancer.
Early marriage and having children early in life, both popular in the Palestinian community, were shown to increase the odds of breast cancer.
The role of oral contraceptives and hormonal replacement therapy on women’s health was also shown and there should be rational use of hormones.
Early age at menarche, late age at menopause, and late age at first full-term pregnancy are linked to a modest increase in the risk of developing breast cancer (breast ca). This study aims to investigate the reproductive determinants of breast cancer among women in the West Bank of Palestine.
A structured questionnaire was used to collect data in a case-control study (237 registered cases and 237 controls). A multivariate analysis model was used to adjust for the association between women’s reproductive factors and breast ca risk. This study was approved by Al Quds University Ethical Research Committee and the Ministry of Health research unit.
In the multivariate analysis, menarche after 13 years of age, use of oral contraceptives for more than two months, and hormonal contraceptives use significantly doubled the risk for breast ca (Adjusted Odds Ratio (AOR) = 2.03, 95 % CI: 1.21–4.37, p < 0.011 and AOR = 2.2, 95 % CI: 1.24–4.01, p = 0.008, respectively). Women who used hormone replacement therapy (HRT) were significantly associated with higher odds (5 folds) of having breast ca versus those who did not use them (AOR 5.02, 95 % CI: 1.93–13.06, p = 0.001). Similarly, nulliparous women showed 6 times the odds of breast ca compared with women with one or more children (p = 0.005). Also, parental consanguinity marriage (AOR 2.59, 95 % CI: 1.53–4.36, p = 0.001) and positive family history (AOR 3.88, 95 % CI: 2.19–6.87, p = 0.001) of the condition can be strong determinants for breast ca in this study.
This study provides clear evidence that the use of reproductive hormones, whether as a birth control tool or for therapeutic purposes, must be rationalized worldwide and in Palestine in particular.
Breast cancer (breast ca) is the most common form of cancer mortality among women in the world [ ]. Breast cancer is a multi-factorial type of cancer. Being genetically predisposed or having a family history of a first-degree relative with breast ca was shown to increase the cancer incidence [ ]. Parental marriage to a relative was also shown to increase the risk [ ]. Among women aged 40 years or more, breast ca is related to increased risk [ , ]. Modifiable risk factors such as obesity, physical inactivity, sedentary behavior, and poor dietary patterns were also shown to be related to breast cancer risk [ ].
The effect of reproductive factors strongly supports a hormonal role in its aetiology [ ]· Early age at menarche, late age at menopause, and late age at first full-term pregnancy are linked to a modest increase in the risk of developing breast cancer [ , ]. However, multiple full-term pregnancies and long-term breastfeeding decrease the risk of breast cancer [ , ].
Reproductive surgeries such as ovariectomy, tubal sterilization, and hysterectomy may also affect the breast cancer risk by altering hormone levels before menopause or by bringing forward the age at menopause [ , ]. Long-term use of hormone replacement therapy (HRT) [ ], but not long-term use of oral contraceptives (OC), was also related to an increased risk of breast ca [ ]. Moreover, it was noted that the time elapsed since last oral contraceptive use was associated with a higher risk of breast ca than recent use [ ].
Breast cancer is the most common and widespread type of cancer in Palestine, and ranks as the third cancer that causes death. It constitutes 17 % of all cancer cases. At the end of 2017, there were 503 new cases documented in the West Bank and 327 new cases recorded in the Gaza Strip. The rate was 33.1 new cases per 100,000 females annually [ ]. Few studies have tackled the risk factors of breast ca in Palestine [ , ]. In Gaza, a study among women aged 18–60 years suggested that a positive family history of breast ca, high body mass index, and some common diseases (hypertension, diabetes mellitus) maybe epigenetic factors that promote the occurrence of breast ca [ ]. The reproductive determinants of breast cancer among women in the southern region of the West Bank will be presented here. The study findings may help to clarify the interaction of these factors in the development of breast cancer among Palestinian women.