Causes of Cancer: From the Perspective of Gynecologic Cancer Survivors

Background: Individuals often have their own personal theories about what may have caused their illness, including cancer. Only a few studies have examined cancer causal attributions in gynecologic cancer survivors. In addition, little attention has been paid to understand other factors associated with causal attributions such as age, ethnicity, and disease-free interval in this subpopulation of cancer survivors.

Aim: The aim of this study was to evaluate the self-reported causes of cancer among the survivors of gynecologic cancers.

Objectives: This study pursued 2 objectives: 1) identify the most common causes of cancer as perceived by gynecologic cancer survivors, and 2) describe the similarities and differences in the causal attributions among gynecologic cancer survivors based on age, ethnicity, and disease-free interval.

Method: A secondary data analysis was conducted on the data previously collected by the author for her dissertation. The original data collection was conducted using a web-based survey among survivors of cervical, ovarian, and uterine cancers.

Discussion: Consistent with the literature, the gynecologic cancer survivors identified heredity and stress as the most important causes of cancer, followed by hormones and environmental reasons. Nonwhite participants reported more significance for diet in cancer development compared with white participants. Compared with long-term survivors, more early survivors thought there is an association between age and cancer.

Conclusion: Gynecologic cancer survivors develop their own beliefs about cancer causes. The findings may be used to modify some of the causes and seek risk-reductive measures by family members.

Early detection and availability of effective treatments have increased the number of individuals with cancer who live much beyond their diagnosis.^1,2 Studies indicate that individuals have various cognitive representations about their illness that may include beliefs about the causes, symptoms, timeline, consequences, and treatment of a given disease or illness. It is known that beliefs about a particular illness can influence risk-reductive behavior and coping.³

Attribution theory suggests that causal attributions are important for a person’s understanding of the world around him or her, and they are important determinants of their interactions with the world. In addition, the attribution theory emphasizes that individuals have a need to understand, give meaning to, and ascribe causation to life events, which helps explain why they are motivated to assign causal beliefs to diseases.⁴ Although there are many known causes of cancers, individuals with active cancer and those who are in the survivorship phase often have their own personal theories about what may have caused their cancer. Many studies have examined the causal attributions among several types of cancer survivors, including breast, prostate, and lung cancer survivors, and, in particular, the relationship of causal attributions and prevention of recurrence of cancer to health practices and distress.^5,6

Cancer survivors’ beliefs about causes of cancer can be different from those of the experts.⁷ The vast majority of the research on causal attributions among cancer survivors has been focused on survivors of breast cancer.^5,8 Although gynecologic cancer survivors account for about 9%,⁹ few studies have examined the causal attributions in this group of survivors. In addition, little attention has been paid to understand other factors associated with causal attributions, such as age, ethnicity, and disease-free interval in this subpopulation of cancer survivors. It is important that those affected by cancer are informed about the causes of cancer, because some of the causes can be modified to reduce the risk of recurrence. Furthermore, this knowledge can also assist unaffected family members to seek risk-reductive measures. Findings from this study will definitely add more understanding about the causes of cancer as perceived by the survivors of gynecologic cancers.

Using data from previous research done by the author, the present study examined the cancer causal attributions among survivors of gynecologic cancer. This study pursued 2 objectives: 1) identify the most common causes of cancer as perceived by gynecologic cancer survivors, and 2) describe the similarities and differences in the causal attributions based on cancer type, age, ethnicity, and disease-free interval.

Methods

The data for this study were previously collected by the author for her dissertation. The original data were collected between March 23, 2013, and May 17, 2013, using a web-based survey. The study approval was provided by the Institutional Review Board of The University of Texas Medical Branch at Galveston. An exploratory descriptive method was used to collect the original data. The sample consisted of English-speaking women ≥21 years of age who were survivors of cervical, uterine, and ovarian cancers and disease-free for at least 2 years following treatment completion.

Measures

For the current study, data from the demographic questionnaire included the participant’s age, ethnicity, and disease-free interval following treatment completion. Consistent with other literature, this study defined survivors as individuals who have completed cancer treatment at least 2 years prior to data collection and have remained disease-free since treatment completion. Those who had been disease-free for 2 to 5 years from cancer treatment completion were considered early survivors, and those who had been disease-free for over 5 years were considered long-term survivors.^10,11 The causal attributions were identified from the previous data that were collected using the Brief Illness Perception Questionnaire (BIPQ).¹² The BIPQ has 9 items: 8 illness representation items and a causal scale. Item 9 is an assessment of the causal representation by open-ended response that asked patients to list the 3 most important causal factors in their illnesses. For the purpose of the current study, only item 9 (the open-ended responses) from the BIPQ was used.

Data Analysis

Descriptive analysis of the data was done using frequency distribution. To examine the similarities and differences based on age, 2 age-groups were created (younger vs older) using a mean split (age 57 years). Ethnicity was also dichotomized due to the small sample sizes in minority groups, which required collapsing the categories, resulting in 2 groups: white versus nonwhite. Based on the disease-free interval, the sample was again divided into 2 groups: early survivors (2-5 years) and long-term survivors (>5 years) following treatment completion.

Results

Six hundred thirty-two women responded to the original survey, and 376 women were found eligible to participate in the original study. Of the eligible subjects, 352 women who completed all questionnaires were included in the final analyses. The mean age of participants was 57.07 years (SD = 10.12; range, 29-80 years). The mean disease-free interval was 5.65 years (SD = 4.71; range, 2-30 years). Demographic characteristics of the sample are shown in Table 1. Women who responded to the survey were from 5 different ethnicities: non-Hispanic white (88.9%), Hispanic white (3.7%), African American (1.4%), Hispanic (2.3%), and Asian (3.7%). Ethnicity was further divided into white (92.6%) and nonwhite (7.4%).

Ovarian cancer survivors were represented the most (59.7%), followed by uterine cancer survivors (31.2%), and cervical cancer survivors (9.1%). Two age-groups were created using a mean split (age 57 years): younger survivors, aged 29 to 57 years (47.2%); and older survivors, aged 58 to 80 years (52.8%). There were more early survivors (65.6%) than long-term survivors (34.4%).

Further analyses were conducted to identify the beliefs of the gynecologic cancer survivors about the causes of their cancer stratified by age-group, ethnicity, and disease-free interval (early vs long-term survivor). The causal item 9 in the BIPQ asked the participants to list the 3 most important causal factors in their illness. The respondents listed 3 important causes of cancer (most important, second most important, and third most important causes). Of the 3 responses to this item, only the most important cause was considered for analyses for this study. The responses were regrouped into 9 best-fit categories: Genetic/Hereditary, Medications/Hormones, Environment, Lack of Follow-up, Stress, Diet, Age, Other Medical Problems, and Other Reasons. The survivors listed several medical reasons and random causes of cancer. These reasons include, but are not limited to, bad luck, infertility/infertility medications, doctor not properly addressing the symptoms, human papillomavirus, frequent exposure to x-rays, age, menopause, use of talcum powder, and promiscuity. Some women did not know what caused their cancer. These items were combined to create 2 categories: Other Medical Problems and Other Reasons. The most important cause of cancer listed by the study participants was used for the purpose of this study. The frequency distribution of the most important causes of cancer across the sample is shown in Table 2.

The majority of the gynecologic cancer survivors reported genetic or hereditary causes as the most important reason for their cancer (28.1%) followed by stress (13.6%), other medical problems (11.9%), environmental causes (9.9%), medications/hormones (8.5%), diet (5.4%), age (4.8%), and lack of follow-up (2.8%). Many nonspecific causes listed by the survivors were added into 1 group, Other Reasons, which represented 14.8% (Table 2). Because Other Medical Problems and Other Reasons include numerous reasons for cancer, only the most specific reasons reported by the participants will be used for further discussion.

To address objective 2, a cross-tabulation was done to identify the similarities and differences in the causes of cancer based on cancer type, age-group, ethnicity, and disease-free interval (early vs long-term survivor) (Table 3).

When comparing younger (aged 29-57 years) and older (aged 58-80 years) survivors, genetic or hereditary causes scored high in both groups (30.7% and 25.8%, respectively). Almost 5% of younger survivors of gynecologic cancer reported hormones or other medications as the cause of cancer versus 12% among the older group. The groups reported an almost equal role for stress: 12.7% (younger survivors) and 14.5% (older survivors). The significance of environment and stress in cancer was the same (12.7%) among the younger cancer survivors in this study. However, older survivors in this study believed stress is more significant (14.5%) than environmental reasons (7.5%) for cancer. Only 1.8% of younger women reported age as a cause for cancer compared with 7.5% of older survivors. Diet was identified by 3.6% of women in the younger age-group as a reason for their cancer versus 7% in the older age-group. More younger cancer survivors identified lack of follow-up as a cause of cancer (4.8%) compared with older survivors (1%).

Further analysis was conducted to compare ethnic groups: white versus nonwhite. The findings are shown in Table 4.

Both whites and nonwhites reported genetic or hereditary reason as the most important reason for their cancer: whites 28.5% and nonwhites 23%. About 11.5% of nonwhite participants reported medications/hormones as well as stress as the cause of their cancer. In addition, 15% of the nonwhite participants named diet as another reason for cancer versus 4.6% by the white participants. Environmental causes were reported by both groups: nonwhites (7.7%) and whites (10%). Lack of follow-up was reported as a less common reason for cancer: nonwhites (4%) and whites (2.7%).

Causal attribution based on disease-free interval is described in Table 5. The results indicate that both early (27%) and long-term (30.6%) survivors of gynecologic cancers reported the genetic/hereditary factor as the most important cause of their cancer. It was also found that 13% of the early cancer survivors and 15% of the long-term survivors believed their cancer was caused by stress.

Early and long-term survivors of gynecologic cancers reported similar significance for other medical problems in cancer development: 11.6% and 12.4%, respectively. In both groups, some individuals believed that medications/hormones caused their cancer: 7.8% and 10%, respectively. The significance of environmental causes was also similar for the 2 groups: 10.4% and 9%, respectively. Lack of follow-up scored low in both groups (Table 5).

Discussion

Gynecologic cancer survivors in this study reported the genetic/hereditary factor as the most important cause of cancer (28.1%), followed by stress (13.6%). In a study by Stewart et al, long-term survivors of breast cancer attributed genetic reasons (26.7%) and stress (42.2%) for their cancer.⁵ Another similar study among breast cancer survivors in Taiwan, Wang and Chung also found a significant cancer causal attribution with heredity (84.4%) and stress (27.5%).⁸ When Costanzo et al⁶ conducted a study to examine whether beliefs about cancer and prevention of recurrence were related to health practices and distress among 134 long-term endometrial and cervical cancer survivors, they also found significant causal attribution to genetics (54%) and stress (46.2%).⁶ A survey by Wold et al of the beliefs about cancer causation in 670 cancer survivors (416 with breast cancer, 165 with prostate cancer, and 89 with colorectal cancer) using a population-based study in Colorado found that regardless of cancer type and gender, >75% believed genetics to be the likely cause of their cancer.⁷ Examination of self-reported causes among prostate cancer survivors in the Netherlands found heredity to be the most reported cause of cancer.¹³ When comparing the early and long-term survivors of cancer in the current study, both groups identified genetic/heredity as the most important cause of cancer (27% and 30.6%, respectively) followed by stress (13% and 15%, respectively). No significant difference was noted in the causal attribution between the early and long-term survivors in terms of these 2 factors. The findings from the current study are consistent with other studies in terms of genetics/heredity and stress as causes of cancer^5-7; however, there is some difference in the percentage, which could be related to the cancer type and/or ethnicity.

Although there is a very slight difference, both white and nonwhite participants in the current study reported stress as an important factor in cancer causation: 14% and 11.5%, respectively. Both men and women in the population-based study in Colorado agreed that stress was acause of their cancer.⁷ Similarly, breast cancer survivors in Taiwan reported stress as a cause of cancer (27.5%).⁸ When surveying the prostate cancer survivors in the Netherlands, 13% considered stress to be associated with their cancer.¹³ When Gonzalez et al examined the causal attribution beliefs among Chinese, Korean, and Mexican American breast cancer survivors, all participants believed that stress caused their cancer.¹⁴ Despite the differences in ethnicity, the cancer survivors in the current study believed there is a relation between stress and cancer, and this finding is consistent with other studies.^7,8,13,14

Of the specific causes for cancer, environment represented the third most common cause (9.9%) across the whole sample in this study. In the study by Kok et al, 17% of the prostate cancer survivors believed environmental factors were linked to their cancer.¹³ Similar results were reported by Stewart et al⁵ (25.5%) and Costanzo et al⁶ (35.9%). The majority of breast cancer survivors (57.6%) in the study by Wang and Chung considered pollution in the environment as the cause of their cancer.⁸ Ratanasiri et al conducted a study using both quantitative and qualitative methods to describe the illness experience and coping mechanisms of cervical cancer patients in Thailand.¹⁵ The qualitative part of this study described patients’ beliefs on the causes of cervical cancer. The first response about cancer belief was “poor working environment causing dirt entering the body.”¹⁵ Differences in the percentage may be related to the differences in the sample.

Only 5.4% of the survivors of ovarian, uterine, and cervical cancer in the current study named diet as the most important cause of cancer. The significance of diet in relation to cancer was found to be higher in other studies: Stewart et al⁵ (15.5%), Costanzo et al⁶ (33.6%), and 46.4% in the study by Wang and Chung.⁸ Women in the study by Wang and Chung also believed food additives caused their colorectal cancer (70%).⁸ Once again, the difference in the causal attribution could be related to the cancer type and/or ethnicity.

Across the whole sample, 8.5% attributed medications/hormones to their cancer. When examining the difference between the groups, 12% of the older survivors considered medications/hormones linked to the cancer compared with 4.8% of the younger survivors. The long-term breast cancer survivors in the study by Stewart et al⁵ reported a 23.9% causal attribution between hormones and breast cancer, whereas the study by Costanzo et al showed a 38.8% attribution to hormones.⁶

Findings from this study suggest that gynecologic cancer survivors develop their own attributions for their cancer illness. Consistent with other literature, the gynecologic survivors in this study also selected heredity, stress, hormones, environment, and diet as specific causes of their cancer. Heredity and stress were the most reported causes of cancer among the survivors of gynecologic cancer, followed by environmental causes and hormones. Both younger and older gynecologic survivors reported heredity and stress as the most important causes of cancer. With respect to hormones, environment, lack of follow-up, and age as causes of cancer, the results from this study showed significant differences between the younger and older gynecologic cancer survivors. Compared with previously reported results, participants in the current study identified diet as a less common cause of cancer. When comparing ethnicity, nonwhites reported a higher role for diet in cancer development compared with white participants. Between early and long-term survivors, the role of various causes was almost equal except age, indicating that more early survivors of gynecologic cancer thought age has an association with cancer.

Implications for Research and Practice

As the number of cancer survivors is increasing, it is important to know what the gynecologic cancer survivors believe caused their cancer. Some of the causes are modifiable, and some are not. Research indicates that beliefs about a particular illness can influence risk-reductive behavior. More attention should be given to improve understanding of modifiable causes of cancer that could impact cancer recurrence. Further, knowledge about the genetic causes of cancer will be beneficial for risk reduction for unaffected family members. In this regard, nurses have an important role for open discussion with their patients about cancer causes. It is recommended that future research use a questionnaire with a list of potential cancer causes rather than an open-ended question, as this will make the analysis less complex.

Limitations

Self-selection bias is a limitation in this study because the participants self-identified their age, ethnicity, and number of disease-free years. The sample had an overrepresentation of ovarian cancer survivors, Caucasian women, and people who spoke English. The causal attributions of cancer were collected by using item 9 of the BIPQ scale, which is an open-ended question that asked patients to list the 3 most important causal factors of their illnesses. This question yielded a wide variety of responses, and analysis was difficult due to the large number of responses to this item.

Conclusion

This study concluded that gynecologic cancer survivors develop their own causes of cancer. Consistent with other studies, gynecologic cancer survivors in this study reported genetic or hereditary causes as the most important reason for the cancer, followed by stress. Of the other specific causes, environment, medications/hormones, diet, age, and lack of follow-up were identified as the next reasons for cancer. In contrast to previously reported studies, gynecologic cancer survivors reported diet as a less common cause of cancer. When comparing ethnicity, nonwhites reported higher significance for diet in cancer development compared with white participants. More early survivors of gynecologic cancer believed age has an association with cancer. The findings from this study can be used to address modifiable causes to reduce cancer recurrence and also to seek risk-reductive measures by unaffected family members.

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