Introduction

Cancer continuous to be a world killer and it account the one of third disease threaten health in the world. According to World Health Organization (WHO); globally during 2012 about 8.2 million people died from cancer. More than 70% of those deaths occurred in low and middle income countries. About 30% of cancer deaths are due to the five-leading behavioral and dietary risks: high Body Mass Index (BMS), low fruit and vegetable intake, lack of physical activity tobacco use and alcohol abuse. Therefore, it could be preserved by modifying or avoiding these risk factors (WHO, 2014)^a [1].

Breast cancer is a critical disease in the global burden of disease; it is the most common cancer in women both in the developed and less developed world. According to World Health Organization (WHO) global health estimates (2013), it is estimated that worldwide over 508000 women died in 2011 due to breast cancer. Although breast cancer is thought to be a disease of the developed world, almost 50% of breast cancer cases and 58% of deaths occur in less developed countries (WHO, 2014) [1].

Breast cancer is the most prevalent cancer in females worldwide and still the most common cause of death in women, with more than 327,000 deaths each year, every year there are 1.35 million new cases and about 4.4 million women are believed to be living with breast cancer, an estimated 1.7 million women will be diagnosed with breast cancer in 2020-a 26% increase from current levels-mostly in the developing world (The Lancet, 2009). The reported incidence rate for breast cancer varies enormously between countries, it was highest in USA, Europe, New Zealand, Canada and Australia, and lowest in Asia and Africa (IARC, 2002) [2].

Breast cancer remains one of the most common cancers in the Eastern Mediterranean region like the whole world, with incidence rate not higher than the developed world, however it affects women in younger ages and is detected at a late stage. Breast cancer still impacts the developing low and middle income countries more than the high-income countries (Sarhan, 2009) [3]. Now breast cancer occupies the number one position in all countries of the Arab World, even if absolute rates are relatively low (Salim et al., 2009) [4]. Cases tend to be young and almost half of patients are below 50, with a median age of 49-52 years as compared to 63 in industrialized nation (Elsughier et al., 2007) [5].

In Gaza Strip, breast cancer is considered a major public health problem. As expected, it is the first common cancer concerning females and the second leading cause of female death after cardiovascular disease. It accounts more than 18.5% of all female cancers. The total number of reported breast cancer was 1283 cases during the years 2009-2014, from them 1207 female cases forming 31.3% of the total cancer cases and 76 male cases forming 1.1% of the total cancer cases. The incidence rate among Gaza women is 149.1 per 100000 women in the period 2009-2014. In addition, the age group 55-64 reported the maximum number of cases 317 forming 24.7% of the total cases; this rate is one third of the rate reported among the American women (WHO, 2016).

Methodology

Study Design

The study designed to be a hospital based case-control study, it was an observational analytical retrospective investigation, and it is very useful to investigate the possible risk factors of breast cancer among women in Gaza Strip.

Study Population

The study population consisted of two types; case group which included accessible breast cancer patients. The total number of available cases was 105 subjects. Double controls were chosen as another type of the tested study population, they were selected from women utilizing the primary health care centers. Total number of controls was 209 subjects; this group of subjects is considered free from breast cancer.

Selection Criteria

Cases

Cases were diagnosed as breast cancer patient. They must be registered in the oncology services archive and their medical services are available in the two selected hospitals.

Diagnosis of the disease was confirmed by histological testing and documented by histological report which should be provided in their files.

Controls

Controls are clinically free from breast cancer as they were chosen from primary heath care centers, thus they may have minor health problems.

Must not suffer from idiopathic weight loss and no history of chronic health problems.

Place of the Study

The first part the study was to collect cases; it was performed at the oncology daycare clinics of both Al Shifa and European Gaza Hospitals, which are considered the main governmental hospitals providing the oncology services to the cancer patients in Gaza strip. Whereas the second part was to collect control, it was established through the primary health care centers of the same governorates to apply the matching process in the place residency.

Data Collection

Data were collected through structured face to face questionnaire. It had been reviewed by 7 experts who are qualified in many fields related to the study. Generally, the questionnaire was included many variables that are directly and indirectly reflects the outcomes needed for the study. Before the beginning of data collection, all questionnaire form prepared, organized and classified with serial numbers to ensure the availability of the needed information. Purpose of the study was explained to the patients before obtaining consent, during the interview any vague information was simplified to ensure exact and real answer by the responders. Great care was taken to ensure privacy and confidentiality.

Pilot Study

Pilot testing had been done prior to the beginning of data collection to check validity of the Questionnaire, refining of questionnaire had been done according to the result of the pilot study.

Period of the Study

The study carried out from January to September 2015.

Response Rate

The study response rate was of high levels. From the 1228, available cases that were going with the inclusion criteria and being asked to participate in the study 105 patients agreed to be a member of the conducted study giving a response rate of 77%.

Controls response rate was even higher to reach 66% that from 140 persons who match with the controls criteria 657 members agree to share in the study.

Ethical Considerations

An informed consent attached to each questionnaire obtained from each participant in the Study. The researcher explained the purpose and the objectives of the study to all the participants, and the inclusion in the study was optional and confidential. Neither name nor personal data had been published.

Statistical Analysis

Statistical Package for Social Sciences version 15 (SPSS, 2007) used for data coding, entry and analysis. Simple distribution and frequencies of the study variables, the cross tabulation, and normal chi square had been applied. P value had been calculated for the ordinal level measures (P< 0.05), variables that are statistically significant by chi square test had been analyzed using odds ratio and 95% confidence interval.

Results and Discussion

The results of the study show the descriptive and inferential analysis of the findings. In general, 314 questionnaires had been filled from the interviewees during face to face interview with the participants, of which 105 were case samples (women with breast cancer) and 209 were control sample (women free from breast cancer).

(Table 1) presents the relationship between socio-demographic variables and breast cancer among cases and controls. Regarding Governorates where cases and controls have been lived, the difference between the two groups did not reach a statistical significant level (P = 0.996). This means that the Governorate does not affect the chance of gettingbreast cancer because the two groups have been matched in regard to governorates.

(Table 2) presents the relationship between kinds of living area and its relationship with breast cancer, difference between the two groups did not reach a statistical significant level also (P= 0.556). This means that neither governorate nor kind of living area in this study affects the chance ofgetting breast cancer because the two groups have been matched in regard to the living area. These results are congruent with Pakseresht case-control study (2009) [6] conducted in Delhi and showed that there was a significant difference between breast cancer cases and controls in relation to the marital status. However, these results do not congruent with another study that has been conducted in West Bank by Darweesh (2009) [7] who found that there was no association between marital status and breast cancer.

As indicated in (Table 3), there is a difference between two groups in terms of age group of both cases and controls and more age women had higher breastcancer. The differencebetween the two groups reach a statistical significant level (P= 0.001). Therefore, age is considered as one of the risk factors that affect the chance of getting breastcancer among women and classified as one of the risk factors that affect breast cancer disease among women. It was reported that breast cancer incidence is very low before age 25, and increases up to 100-fold by age 45 (Hulka and Moorman, 2001) [8].

(Table 4) presents the marital status and its relationship with breast cancer, the difference between the two groups did not reach a statistical significant level also (P= 0.531). This means that the material status does not affect the chance of getting breast cancer because the two groups have been matched in regard to material status. These results are agreeing with Pakseresht case-control study (2009) [6] conducted in Delhi and showed that there was a significant difference between breast cancer cases and controls in relation to the marital status. However, these results congruent with another study that has been conducted in West Bank by Darweesh (2009) [7] who found that there was no association between marital status and breast cancer.

(Table 5) represents the relationship between breast cancer and number of children indicates the difference between the two groups did not reach a statistical significant level (P= 0.007). This means that number of children have no effects on the chance of getting breast cancer so it has no association with breast cancer among women in Gaza Governorate.

(Table 6) shows that 12.4% of cases workers women compared to 10.5% of controls, while 87.6% of cases did not have a work compared to 89.5% of controls. The difference between two groups did not reach a statistical significant level (P= 0.622, OR 0.201). This factor does not affect the chance of getting breast cancer so it does not consider as a risk factor of breast cancer.

As indicated in (Table 7), there is a no difference between two groups in terms of educational level of both cases and controls the difference between the two groups doesn’t reach a statistical significant level (P= 0.369). Therefore, education does not consider as one of the risk factors that affect the chance of getting breast cancer among women.

(Table 8 and Table 9) illustrate the difference between the two groups in housing type and place of living also doesn’t reach a statistical significant level (P= 0.020 and 0.891) respectively, indicating that housing type and place of living doesn’t affects the chance of getting breast cancer disease.

Conclusion

There is a difference between two groups in terms of age group of both cases and controls. The difference between the two groups reach a statistical significant level (P= 0.001), otherwise no other socio-demographic data reached a statistical significant level. Therefore, more aged women had higher breast cancer 79% (n= 83) more than 40 years old. Breast cancer incidence is very low in age group between 18-25 years about 1.9%, moderate incidence in age group between 26-40 years about 19%.  Age is considered as one of the risk factors that affect the chance of getting breast cancer among women. Also, classified as one of the risk factors that affect breast cancer disease among women.

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