Research
Assessing the occupational history of breast cancer patients undergoing radiation therapy and chemotherapy: retrospective-study
11Donkor Andrew,1&2Kyei Kofi Adesi 1 Asare-Sawiri Michael 3and 3Konney Nii Okpoti
- 11Korle-Bu Teaching Hospital, Ghana;
- 22University of Ghana, College of Health Sciences, School of Allied Health Sciences;
- 3 Komfo Anokye Teaching Hospital, Ghana
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ((http://creativecommons.org/licenses/by/3.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Abstract
Background
Breast cancer, a disease of both the developing and the developed world’s is the leading type of cancer in women. Its incidence in a year is approximately 20-25 per 100,000 women, varying from region to region, and this rate is continuously increasing over the past decade. There is contradictory evidence on whether occupation is a risk factor for breast cancer. It has been reported that clerical workers, teachers, medical and health care personnel, agricultural workers, and some industrial workers are at greater risk of developing breast cancer. Our study aims at assessing the occupational history of breast cancer patients undergoing radiation therapy and chemotherapy
Materials and Methods
A self-administered questionnaire on socio-demographic, known risk factors and occupational history was given to eighty-one breast cancer patients undergoing radiation therapy at the Korle-Bu Teaching Hospital. SPSS software version 14 was used to analyse the data.
Results
Eighty-one eligible breast cancer patients undergoing radiotherapy and chemotherapy participated in the study. The age range was 31-76 years and the mean age was 51.7 years (standard deviation of 10.9 years). 70.3 of the participants at the time of study were married and 22.2% indicated that they had basic education. Most (75.3%) of the patients were employed. Majority of the participants were traders (50.8%) with a minimum working duration of 8 years and a maximum of 49 years. 87.7% of the participants had never worked with equipment and 18.5% of the participants had been working with chemicals.
Conclusions
The study identified trading to be the major occupation among the participants. There was however increased alcohol consumption among the participants
Keywords
Occupation, Breast cancer, Risk factor
Background
Breast cancer is a disease of both the developing and developed worlds [1] and the leading cause of cancer death among women of 35–54 years [2].
The incidence of breast cancer according to Chaiweerawattana (2008), in each year is approximately 20-25 per 100,000 women, and the corresponding rate is continuously increasing over the past decade [1]. Also ,according to Perkin et al (2005), over one million women were diagnosed of breast cancer worldwide in 2002 [3], whereas in 2011, an estimated 230,480 new cases of invasive breast cancer were diagnosed among women, as well as 57,650 additional cases of in-situ breast cancer [].
Major reasons for the increased in breast cancer worldwide may include improvement in diagnosis, adoption of western life style, increased age at first birth and decrease in parity, family history or personal history of breast cancer and hormonal factors [5,6]. These factors alone cannot fully explain the increasing trend of breast cancer in Ghana and the rest of the world. Many environmental risk factors for breast cancer are still unknown especially in relation to occupation [7]. Occupational factors have not been shown to be a major cause of breast cancer [8]. Occupation in this context is a job; a regular activity performed for payment that occupies one's time [9]. These include teaching, health and social care, mining and quarrying, farming and fishing, manufacturing, transportation and many others.
Occupational studies conducted in Asian populations’ show that a high level of chemicals have been shown to induce mammary tumours in animals [10] and risks of breast cancer have been reported among clerical workers, teachers, medical and health care personnel, agricultural workers, and some industrial workers [11,12]. The workplace can expose women to chemicals, physical and biological agents that could influence breast cancer risk. They could be exposed to several health hazards in their working environment including occupational carcinogen such as ionizing radiation, polycyclic aromatic hydrocarbon, and pesticides [13,16].
A study conducted at the Korle-Bu Teaching Hospital reported 21.4% of the cancer cases undergoing radiotherapy and chemotherapy were breast cancer cases [17] and it is expected to increase by 2015. It is also estimated that 27,060 new cases of breast cancer will be diagnosed among African Americans and 6,080 will die from the disease in 2013 [18]. There are several risk factors of breast cancer [19] and studies are attributing the development of the disease to occupational exposures [20]. The study sought to assess the occupational history of breast cancer patients undergoing radiation therapy and chemotherapy.
Material and methods
A retrospective research design was used to collect data from breast cancer patients undergoing radiotherapy and chemotherapy at the Korle-Bu Teaching Hospital, Accra-Ghana. Patients were identified and recruited at the outpatient department whiles waiting to be seen by their care givers (oncologist, nurse or radiation therapist) for treatment.
A self administered pre-tested questionnaire consisting of three sections (A, B and C) was used to gather information from participants. Section A gathered the participants’ socio-demographic information, including the age, gender, marital status, education, religion and ethnic group. Section B also gathered information on known risk factors such us family history of breast cancer, use of contraceptives and alcohol intake and Section C gathered information on participants’ occupational history.
Participants who could not read nor write English were guided by the researchers to complete the questionnaire. The questionnaire was administered from 6th August 2012 to 28th January 2013.
Consent was obtained from each participant prior to the administration of the questionnaire and ethical approval was obtained from the National Centre for Radiotherapy and Nuclear Medicine, Korle-Bu Teaching Hospital. Participants were selected by simple random sampling provided they meet the following criteria; diagnosed of breast cancer and referred to Korle-Bu Teaching Hospital for management. Patients who were blind, deaf and dumb, mentally retarded or been managed on emergence basis were excluded. Eighty-one questionnaires were given out and a 100% response rate was attained. Confidentiality of the information that the participants provided was ensured.
The data collected were analysed using SPSS software version 14. Data analysis was performed using frequencies and percentages. Descriptive statistics such as mean and standard deviations were calculated. A p-value of 0.05 was considered significant.
Result
Eighty-one eligible breast cancer patients undergoing radiotherapy and chemotherapy participated in the study. The age range was 31-76 years and mean age was 51.7 years (standard deviation of 10.9 years). 70.3% of the participants were married and 22.2% have had a basic education (Table 1).
|
Cases |
|
N |
% |
| Age group (year) |
|
|
| 31-40 |
11 |
13.5 |
| 41-50 |
21 |
27.2 |
| 51-60 |
35 |
38.3 |
| >60 |
16 |
21.0 |
| Marital status |
|
|
| Married |
57 |
70.3 |
| Divorced |
8 |
9.9 |
| Widow |
8 |
9.9 |
| Never married |
8 |
9.9 |
| Religion |
|
|
| Christian |
76 |
93.8 |
| Muslim |
5 |
6.2 |
| Educational attainment |
|
|
| Uneducated |
17 |
21.0 |
| Basic/Secondary education |
34 |
42.0 |
| Tertiary/Postgraduate education |
30 |
37.0 |
| Ethnic group |
|
|
| Akan |
41 |
50.6 |
| Ga/Ga-Adangbe |
18 |
22.2 |
| Ewe |
13 |
16.1 |
| Mole-dagbani |
3 |
3.7 |
| Others |
6 |
7.4 |
wo and half percent of the participants did not know the age they started menstruating whiles 12.3% started menstruating at the age of 12 years. The mean age of menstruating was 14.6 years (standard deviation of 2.9 years). The age range for first child birth was 20-32 years and the mean age was 23.3 years (standard deviation of 8.9 years). 87.7% of the study participants had given birth before. 32.1% of the participants had a history of oral contraceptive use and it was common among educated women (p= 0.01). 56.3%, 48.1% and 66.7% of the participants with a secondary, tertiary and post-graduate educational level respectively had a history of using oral contraceptive (Table 2).
|
|
Cases |
|
N |
% |
| Age at menarche (year) |
|
|
| 9-16 |
65 |
80.2 |
| 17 or older |
14 |
17.3 |
| Don’t know |
2 |
2.5s |
| Menopause |
|
|
| Yes |
49 |
60.5 |
| No |
32 |
39.5 |
| Oral contraceptive |
|
|
| Yes |
26 |
32.1 |
| No |
35 |
67.9 |
| Family history |
|
|
| Yes |
10 |
12.3 |
| No |
54 |
66.7 |
| Don’t know |
17 |
21.0 |
| Parity |
|
|
| Yes |
71 |
87.7 |
| no |
10 |
12.3 |
| Age at first birth a (year) |
|
|
| ≤20 |
4 |
5.6 |
| 21-30 |
65 |
91.6 |
| 31+ |
2 |
2.6 |
| Alcohol intake |
|
|
| yes |
30 |
37.0 |
| no |
51 |
63.0 |
| Smoking |
|
|
| Yes |
11 |
13.6 |
| no |
70 |
86.4 |
a for parous women only
Vast majority of the study participants were employed (75.3%) and 16.1% were unemployed. 8.6% of the participants were on pension. Majority of the participants were traders (50.8%) with a minimum working duration of 8 years and a maximum of 49 years. The mean working duration was 23.0 years (standard deviation was 12.7 years). Participants were asked if they have ever worked with any equipment, 87.7% had never worked with equipment and 12.3% reported working with equipments.18.5% of the participants had been working with chemicals and 81.5% had never worked with any chemical.(Table 3)
|
Duration of working (years) |
|
|
|
≤10 |
11-20 |
21-30 |
31-40 |
≥41 |
|
Total |
| Occupational Group |
|
|
N |
|
|
N |
% |
| Sales |
|
|
|
|
|
|
|
| Traders |
1 |
8 |
9 |
11 |
2 |
31 |
50.8 |
| Executive, administrative & managerial |
|
|
|
|
|
|
|
| Managers and administrators |
0 |
0 |
2 |
0 |
0 |
2 |
3.3 |
| Professional |
|
|
|
|
|
|
|
| Teachers/Lecturers |
0 |
2 |
5 |
0 |
0 |
7 |
11.5 |
| Nurses |
0 |
0 |
0 |
6 |
0 |
6 |
9.8 |
| Writers |
0 |
0 |
0 |
1 |
0 |
1 |
1.6 |
| Farming, forestry and fishing |
|
|
|
|
|
|
|
| Farmers |
0 |
0 |
2 |
0 |
0 |
2 |
3.3 |
| Fish mongers |
0 |
2 |
1 |
0 |
0 |
3 |
4.9 |
| Building construction |
|
|
|
|
|
|
|
| Labourers |
0 |
0 |
1 |
0 |
0 |
1 |
1.6 |
| Other services |
|
|
|
|
|
|
|
| Civil Servants |
2 |
2 |
0 |
0 |
0 |
4 |
6.6 |
| Caterers |
0 |
0 |
0 |
2 |
0 |
2 |
3.3 |
| Seamstress |
0 |
2 |
0 |
0 |
0 |
2 |
3.3 |
| Total |
3 |
16 |
20 |
20 |
2 |
61 |
100 |
Discussion
The study sought to examine the occupational history of breast cancer patients undergoing radiation therapy and chemotherapy. All Participants approached and invited to participate in completion of the questionnaire did so willingly.
From the study, the mean age of the participants was 51.7 years, which was slightly higher than a study conducted in the same hospital involving 66 newly diagnosed breast cancer patients (mean age= 44.8 years) [21]. Married women were more likely to be engaged in an occupation (p=0.02). Studies suggest that educational level is associated with increased risk of breast cancer [22,23]. This increased risk in highly educated women may be due to the western life style, dietary changes, decreased exercise, obesity, and late age at first birth or decreased breast-feeding.
One of the strongest risk factors of breast cancer is family history of the disease [24]. From the study, 12.3% of the participants had a family history of breast and 21.0% did not know whether a relative had been diagnosed of breast cancer before. Thirty-seven percent of the participants had a history of alcohol consumption and 63% had no history of alcohol consumption before and after diagnosis of the disease. Studies have shown that high alcohol consumption is a risk factor of breast cancer [25]. From the results, 31.7% of the Akan participants and 43.8% of the Ga participants had a history of alcohol consumption. Also, alcohol consumption was associated with educational level (p= 0.04). One hundred percent of the participants with postgraduate educational level had a history of alcohol consumption. Other studies have also shown strong alcohol consumption among graduates [26].
In a population-based study, there was a clear and reliable association between late age at menopause and breast cancer risk. It was also estimated that there was 2.8% increase in breast cancer risk for every year of delay in menopause [27]. From the results, 60.5% of participants were in their menopausal age whereas 39.5% were still menstruating. Twenty percent of the participants within the age range 61-65 years were still menstruating at the time of the study indicating late menopause among the study population.
From the study, 75.3% of the study participants had occupational history with trading as the major occupation representing 50.8%. In a developing country such as Ghana, trading is seen to be very common among participants. Likewise, uneducated patients were more likely to engage in trading (p=0.001). Traders are more likely to be exposed to ultraviolet rays from the sun because most of them do not work under sheds. Also, from the study, 12.3% of the participants had been working with equipments and 18.5% have been exposed to chemicals one way or the other. All the participants who were engaged in farming have been exposed to chemicals when carrying out their working activities (p=0.001). Farmers use pesticides and herbicides to control pests and weeds respectively. Ghanaian farmers are known for using dichlorodiphenyltrichloroethane (DDT). Studies have shown that exposure to organic solvents before age 36 years increases risks of breast cancer [28] because breast tissues are more responsive to adverse effects if exposure occurs when breast cells are proliferating.
.
Also, all the nurses (100%) reported working with chemicals at their workplaces and had been on shift work (that is night work). Exposure to night shift working has been identified as a most significant occupational exposure associated with breast cancer [20]. Exposure to light at night disturbs the circadian system which causes alterations to sleep-activity patterns resulting in an increased oxidative stress. The end effect is suppression of melatonin production and deregulation of circadian genes which are involved in cancer-related pathways [
29].
The study is limited by the low number of participants. Additional it is a hospital based study; there maybe some patients who had surgery but refused to undergo radiotherapy and chemotherapy.
In conclusion, trading was identified to be the major occupation at the study site among the participants and increased alcohol consumption among breast cancer patients.
Competing interest
The authors declare that they have no competing interests
Author’s contribution
AD: Concept formulation, questionnaire administration, statistical analysis and drafting of script.
KAK: Concept formulation and drafting of script.
NOK: Drafting of script.
MA-S: Drafting of script.
All authors read and approved the final manuscript
Funding
None
References
[1]Chaiweerawattana A. Breast Cancer in Thailand 1998-2000, Bangkok Medical Publisher, Bangkok, 2008; 4: 48-53.
[2]Parkin DM, Bray FI, Devesa SS. Cancer burden in the year 2000. The global picture. Eur J Cancer 2001; 37:S4–S66[pubmed]
[3]Parkin DM, Bray F, Ferlay J. Global cancer statistics, 2002. CA Cancer J Clin 2005; 55:74–108 [pubmed]
[4]American Cancer Society. Breast Cancer Facts & Figures 2011-2012. Atlanta: American Cancer Society, Inc.
[5]Jin F, Shu XO, Devesa SS, et al (1993). Incidence trends for cancers of the breast, ovary, and corpus uteri in Shanghai, 1972–90. Cancer Causes Control 4:355–360[pubmed]
[6]Gao YT et al. Association of menstrual and reproductive factors with breast cancer risk: results from the Shanghai Breast Cancer Study. Int J Cancer 2000; 87:295–300.[pubmed]
[7]Key TJ et al (2001). Epidemiology of breast cancer. Lancet Oncol 2001; 2, 133-40.[pubmed]
[8]Zahm SH, Blair A. Occupational cancer among women: where have we been and where are we going? Am J Ind Med 2003; 44:565–575.[pubmed]
[9]Wikipedia (2012). Occupation [http://en.wikipedia.org/wiki/Occupation]. (1/09/2012).
[10]Benett LM, Davis BJ. Identification of mammary carcinogens in rodent bioassays. Environ Mol Mutagen 2002; 39:150–157.[pubmed
[11]Gardner KM et al. Occupational and breast cancer risk among Chinese women in urban Shanghai. Am J Ind Med 2002; 42:296–308[pubmed]
[12]Peplonska B, Szeszenia-Dabrowska N. Occupational risk factors for breast cancer in the epidemiological studies. Med Pr 2001; 52, 483-95.[pubmed]
[13]Caplan LS, Schoenfeld ER, O’Leary ES, et al. Breast cancer and electromagnetic fields-a review. Ann Epidemiol 2000; 10, 31-44.[pubmed]
[14]Buranatrevedh S, Roy D. Occupational exposure to endocrine-disrupting pesticides and the potential for developing hormonal cancers. J Environ Health 2001; 64, 17 29[pubmed]
[15]Jaga K, Dharmani C. The epidemiology of pesticide exposure and cancer: A review. Rev Environ Health 2005, 20, 15-38[pubmed]
[16]Petralia SA et al. Risk of premenopausal breast cancer in association with occupational exposure to polycyclic aromatic hydrocarbons and benzene. Scand J Work Environ Health 1999; 25, 215-21.[pubmed]
[17]Yarney J, Donkor A, Opoku SY, et al. Characteristics of users and implications for the use of complementary and alternative medicine in Ghanaian cancer patients undergoing radiotherapy and chemotherapy: a cross-sectional study. BMC Complementary and Alternative Medicine 2013 13:16.[pubmed]
[18]DeSantis C, Naishadham D, Jemal A. Cancer Statistics for African Americans. CA Cancer J Clin 2013; 00:1-16.[pubmed]
[19]Colditz GA, Baer HJ, Tamimi RM (2006) Breast cancer. In Cancer Epidemiology and Prevention, Schottenfeld D, Fraumeni JF (eds) 3rd edn, pp 995 –1012. OUP: New York[pubmed]
[20]Megdal SP, Kroenke CH, Laden F, et al. Night work and breast cancer risk: a systematic review and meta-analysis. Eur J Cancer 2005; 41, 2023-32.[pubmed]
[21]Clegg-lamptey J, Dakubo J, Attobra YN. Why do breast cancer patients report late or abscond during treatment in Ghana? A pilot study. Ghana Med J. 2007: 43(3); 127-131 [pubmed]
[22]Helmrich SP, Shapiro S, Rosenberg L: Risk factors for breast cancer. American J Epidemiology 1983, 117:35-45[pubmed]
[23].Tavani A, Braga C, Vecchia L: Attributable risk for breast cancer in Italy: education, family history and reproductive and hormonal factors. 1997, 70:159-163[pubmed]
[24]Tsuchiya M, Iwasaki M, Otani T, Nitadori J, Goto K, Nishiwaki Y, Uchitomi Y, Tsugane S: Breast cancer in first-degree relatives and risk of lung cancer: assessment of the existence gene sex interactions. Jpn J Clin Oncol 2007, 37:419-423.[pubmed]
[25]Longnecker MR. Alcoholic beverage consumption in relation to risk of breast cancer: meta-analysis and review. Cancer Causes Control 1994; 5:73-82[pubmed]
[26]Reavley NJ, Jorm FA, McCann VT, et al. Alcohol consumption in tertiary education students. BMC Public Health 2011; 11:545.[[pubmed]
[27]Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormone replacement therapy: collaborative reanalysis of data from 51 epidemiological studies of 52,705 women with breast cancer and 108, 411 women without breast cancer. Lancet 1997; 350:1047–59.
[28] Labrèche F, Goldberg MS, Valois MF, Nadon L. Postmenopausal breast cancer and occupational exposures. Occup Environ Med 2010; 67:263e269[pubmed]
[29]Stevens RG, Blask DE, Brainard GC, et al. Meeting report: the role of environmental lighting and circadian disruption in cancer and other diseases. Environ Health Perspec 2007; 115(9): 1357[pubmed]
ASSESSING THE OCCUPATIONAL HISTORY OF BREAST CANCER PATIENTS UNDERGOING RADIATION THERAPY AND CHEMOTHERAPY
SECTION A: SOCIO-DEMOGRAPHIC INFORMATION
1. Gender: • Male • Female
2. Age: …………………
3. Marital Status: • Married • Divorced • Widow • Never Married
4. Religion: • Christian • Muslim • Traditionalist
5. Ethnic group: •Akan •Ga-Dangme •Ewe •Guan •Gurma •Mole-Dagbani •Grusi •Mande •Others
6. Education level: • Uneducated • Basic Education • Secondary Education
• Tertiary Education • Postgraduate Education
SECTION B: KNOWN RISK FACTORS INFORMATION
7. At what age did your menstrual periods begin? (Females only; Mark only one answer.)
• never menstruated
• 9 or younger
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17 or older
• don’t know
8. Are you still having menstrual periods? • Yes • No
9. Have you ever used oral contraceptives for two months or more for any reason? • Yes • No
10. Did any of your parents, siblings, or children have breast cancer?
• Yes • No • Don’t know
11. Have you ever given birth before? • Yes • No
12. If Yes, at what age? ………………
13. How many children? ……………..
14. Have you ever taken alcohol before? • Yes • No
SECTION C: OCCUPATIONAL INFORMATION
15. Are you employed? • Yes • No • Pensioner
16. What kind of occupation? ………….
17. How many months or years have you been working? …………
18. What were your main responsibilities? ………..
19. Where you working with equipments/machines? • Yes • No
20. If Yes, what kind of equipments/machine did you use? ………….
21. Where you working with chemicals? • Yes • No
22. If Yes, what kind of chemicals? …………….
