ABSTRACT

A significant number of scientific data concerning breast cancer is generated in Turkey. The present research reviewed postgraduate theses examining the psychological evaluation of breast cancer patients conducted in Turkey. The objective of the review study was to ascertain the focal topics of the theses, identify commonly examined psychological variables, determine research gaps, compare the frequency of experimental and intervention studies with other kinds of research, and provide recommendations for literature. A retrospective descriptive study was designed by performing a search on the YÖK Thesis Center website with the keywords “breast cancer” and “psychology” (in Turkish and English) between 2000 and 2024. The criteria for inclusion in the review study required that the dissertation be a master’s or doctoral thesis in psychology, involve breast cancer patients as participants, focus on patients who are not in remission, and be available as open access. Twenty-seven postgraduate theses were selected. Of the theses 88.9% were classified as master’s theses, while 11.1% were categorized as doctoral theses. Although the variables included in the these studies were numerous, some were investigated more often. “Post-traumatic growth” was evaluated by 12 theses, “perceived social support” by 6, “depression-anxiety-stress” by 15, and “coping” by 8. more frequently observed factors include metacognition, ruminative thinking, schemas, body perception/image, and self-esteem. Most of the studies were relational and non-interventional. Only three studies used psychological intervention. It is suggested that thesis studies should include more participant characteristics, control for them in analyses, and be more experimental and effectiveness focused.

Introduction

Breast cancer is defined as a disease with different subtypes and different characteristics (1). Characterized by a tumor found in the breast tissue, this disease can usually be seen in the lobules and milk ducts that produce milk (2). According to World Health Organization data, breast cancer has been reported as the most common type of cancer in women worldwide, and approximately 2.3 million people have been diagnosed with this disease as of 2023 (3). Although it is known to be mostly common among women, the incidence of this disease in men is between 0.5% and 1% (3). When breast cancer statistics in Turkey were examined, the most up-to-date information was from 2018, and it was reported that the lifetime probability of contracting this disease is 1 in 8 (4). The fact that 1 in 4 women diagnosed with cancer have breast cancer and that the age of onset is decreasing (4) shows that this disease should be considered a public health concern in Turkey.

Recent literature indicates advances in the diagnosis, prognosis, and therapy of breast cancer. Surgical and oncological treatments (radiotherapy, chemotherapy and hormone therapy) are the most widely used methods for this disease (5). In addition to all the physical effects after a cancer diagnosis, another important consideration for the patient is survival (6). Naturally, psychological variables come into play in this process and can affect the prognosis of the disease, the quality of life and the psychological state of the patient (7). The most common psychological processes are depressive symptoms, anxiety, stress and trauma symptoms (8). Their levels may vary depending on individuals, the stage of cancer, the type of treatment and the person’s environmental support (9).

Another area at the intersection of breast cancer and psychology is psychological intervention. The importance of adding psychological treatments to all treatment protocols in addition to medical treatments for breast cancer patients has been highlighted (10). Both types of treatment can improve the quality of life by treating the patient holistically (11).

The information reviewed above is the results of scientific studies. Academic knowledge is produced in a certain systematic order and presented to the literature in different forms (12). Theses are one form of academic knowledge production. These studies, which are conducted as part of postgraduate education, both improve students’ academic knowledge and skills and expand the academic literature (13). While breast cancer literature is rapidly developing both internationally and nationally, it may be seen that some variables are frequently repeated and similar methods are used, especially in postgraduate theses in the national literature. In addition, when preparing postgraduate theses, what kind of studies (knowledge gaps) are needed may be overlooked.

Evaluation of these problems were the aim of the current study. Postgraduate theses prepared in universities in Turkey examining the psychological characteristics of breast cancer patients were reviewed and the results obtained within the scope of the above information constituted the output of this review. Especially in the field of breast cancer, the psychology literature is increasing, and it is necessary to identify the knowledge gaps with a more general view for the studies to be carried out. Thus, psychology theses including breast cancer patients were reviewed. By reviewing both general information about the theses (such as the year the thesis was written, the type of the thesis, the title of the academic advisor) and the content information of the theses, questions emerged as to which areas the studies were concentrated in the theses, which variables and methods were less often addressed in the studies, and what the distribution was in terms of participant characteristics.

The findings obtained through this review will guide future studies to areas of need, will provide methodological strengthening of new thesis studies, and will demonstrate the accumulation of knowledge revealed over the years by presenting a summary of the postgraduate theses conducted to date. With this review, a general scope assessment will be made for future studies and points to be considered will be highlighted.

Literature Search Strategy

A review was created for the purpose of retrospectively examining postgraduate theses written in Turkey and registered with the YÖK Thesis Center, which included the subject of breast cancer. For this purpose, the research was designed in a retrospective descriptive method. To provide the data for the current study, a search was conducted between 10.06.2024 and 10.07.2024 on the web page of the Council of Higher Education Thesis Center (2024). The keywords “breast cancer” and “psychology” were first used for the search (in Turkish and English) between the years 2000 and 2024. Then, from the advanced search tab, the department was limited to “Psychology Department”, “General Psychology Department” and “Clinical Psychology Department”.

Inclusion/Exclusion Criteria

The review includes studies that were published prior to July 2024. The inclusion criteria were:

1. Language: Theses written in Turkish or English.

2. Population: Breast cancer patients.

3. Intervention, comparator, and outcome: postgraduate psychology theses that accept breast cancer patients as participants and investigate psychological processes.

4. Study design: Quantitative or qualitative designs.

The exclusion criteria were: (1) closed to access; (2) population: participants were breast cancer patients in remission; (3) main field: a field outside the department of psychology.

Procedure

The examined theses were accessed via the YÖK Thesis Center web page. For theses uploaded to this system, authors can manage whether to give approval for sharing the information of theses while logging into the system. Therefore, theses that have been approved can be examined. For this reason, it was not necessary to obtain approval from the authors of the theses and the ethics committee.

The abstracts and titles of the acquired studies were subsequently assessed. Studies eligible for open access were determined by the analysis of the abstract and title. The qualifying theses were identified subsequent to the study review. The author extracted data from each study. This data encompasses the study’s author, year, title, country, objective, participants, data collection method, scales, research design, methodologies, and research findings.

In the review it was found that the studies were quite heterogeneous about method, even though only quantitative and qualitative studies were examined. The investigations exhibited significant variations in several aspects, including the socio-demographic and medical attributes of the participants, the instruments utilized, and the variables analyzed. This may complicate the meta-analysis procedure. Consequently, it was posited that narrative synthesis would be appropriate for analyzing psychological characteristics in studies involving breast cancer patients (14).

In the initial search, there were 1769 theses, of which 1728 were from other fields (medicine, social work etc.) and were removed. The author screened the titles and abstracts of the 41 remaining theses by considering the inclusion and exclusion criteria. After screening the titles and abstracts, an additional 14 were removed for the following reasons: Six included participants in remission period; five included both breast cancer patients and relatives; two were on breast cancer but without a diagnosis from the participants; and one was inaccessible. This resulted in 27 these being included (Figure 1).

The data of the studies evaluated were entered into SPSS for Windows, version 25.0 (IBM Inc., Armonk, NY, USA). A separate column was defined for each variable to be examined. A separate table was created for the findings of the theses examined and the findings of the theses were summarized.

Results

The characteristics of the theses selected for the present study are summarized in two tables. Table 1 contains general information about the theses, while Table 2 contains summary information about the theses’ contents.

A total of 27 postgraduate theses that met the specified criteria were examined. Of these, 24 (88.89%) were master’s theses and only 3 (11.11%) were doctoral theses. The examined studies were published in the YÖK Thesis Center between 2011 and 2023. When the characteristics of the candidates’ advisors were examined, 2 (7.40%) had two advisors (Asst. Prof. Dr. and Assoc. Prof. Dr.), 13 (48.14%) had one Assoc. Prof. Dr., 2 (7.40%) had an advisor with the title of Prof. Dr. and 10 (37.03%) had an advisor with the title of Asst. Prof. Dr.

In terms of the methods used, 10 (37.03%) were descriptive and cross-sectional, 2 (7.40%) used descriptive and cross-sectional methods together with scale adaptation studies, 9 (33.33%) were of the causal comparative type, 2 (7.40%) used the longitudinal type, 3 (11.11%) were of randomized controlled design examining the effectiveness of a psychological intervention and 1 (3.70%) was prepared using the qualitative method. The number of participants varied between 3 and 201. There were 10 (37.03%) that included a control/comparison group. In 20 (74.07%) data and applications were conducted face-to-face, in 4 (14.81%) online and in 4 more (14.81%) both face-to-face and online applications were conducted (Table 1).

Although the variables examined in the theses were several, some variables were investigated more frequently. In particular, the post-traumatic growth variable was examined by 12 theses, perceived social support by 6 theses, depression-anxiety-stress by 15 theses, and coping variable by 8 theses. In addition to these, metacognition, ruminative thinking, schemas, body perception/image and self-esteem are among the variables encountered more frequently than others. Most of the studies were relational in design and did not include intervention. However, three of the studies included psychological intervention.

The stages of breast cancer, whether they had undergone surgery, whether they received complementary treatment, and whether they had metastases and other cancer diseases were all assessed in the context of the participants’ characteristics. This showed that 12 (44.44%) did not provide information on the stage of cancer in the participants; only 1 study (3.70%) had stage 1 and 2 breast cancer in the participants, 6 studies (22.22%) had stage 1, 2 and 3 breast cancer in the participants, and 8 studies (29.62%) accepted patients in stage 1, 2, 3 and 4 as participants. When the additional treatment status of the participants was examined, 5 (18.51%) did not provide information about the participants’ status, 14 studies (51.85%) included patients who received radiotherapy, chemotherapy and hormone therapy, 6 (22.22%) included patients who received radiotherapy and chemotherapy, 1 (3.70%) included patients who received only chemotherapy and 1 (3.70%) included patients who received only hormone therapy. While participants were those who had undergone surgery in 24 studies (88.9%), patients who had not undergone surgery were recruited in 1 thesis (3.70%). In addition, information was not obtained about whether patients had undergone surgery in 2 studies (7.40%). In 21 of the examined thesis studies (77.8%), no information was given regarding the metastasis status of the participants, while in 6 studies (22.22%), information was collected regarding metastasis status. In addition, in 23 studies (85.15%), no information was found regarding whether the participants had cancer other than breast cancer; in the remaining 4 studies (14.81%), information was available on this subject (Table 2).

Discussion and Conclusion

In the present study, postgraduate theses produced in Turkey that examine the psychological processes of breast cancer patients were reviewed. Also, the criteria determined for the selection of theses and the findings obtained are discussed together with the relevant literature and suggestions for future studies are presented.

First, some criteria were determined in the selection of theses to be used in the review study. These are detailed in the method section (Figure 1). Thesis studies that accepted patients in remission as participants, which is considered an important criterion, were excluded. Especially in the field of oncology, the meaning of the word remission is the decrease in cancer symptoms and burden. It is also emphasized that a single method-based decision will not be sufficient for the decision of the remission period in cancer, and that the results obtained only with pathological and radiological measurable tools will not provide a complete prediction (15). Therefore, cancer survival is related to some psychosocial processes. In this survival phase, the psychological needs and characteristics of the individual may differ from the disease period (15). For these reasons and because it was suitable for the purpose of the study, studies conducted with patients in remission were determined as an exclusion criterion for the review.

The initial observation was the absence of homogeneous structures when the studies were analyzed in terms of participant characteristics, even though the theses under review made contributions to related literature. For example, the characteristics of the participants’ cancer and treatment stages were not separated in many studies. It is suggested that this should be considered as a limitation. There are studies supporting this suggestion (16, 17). In the study by Costa-Requena et al. (18), patients showed different characteristics in terms of social, familial, emotional well-being and psychological stress at different stages. Although there are studies showing that the psychological characteristics of individuals do not change according to the cancer stages in terms of psychological needs and characteristics, it is recommended that this be checked and analyzed. Another striking finding was that the participants’ complementary treatment information (radiotherapy, chemotherapy, hormone therapy, etc.) and information on the metastasis status of the cancer were not considered or provided. This is an additional limitation. The fact that this information regarding the medical conditions of the participants in the theses is not considered or is incomplete may be related to the fact that education in psychology does not include sufficient health-disease information. An estimated cause for the lack of information on this variable, which should be adjusted for, is the prevalence of relationship designs in research, which often neglect the gathering of information based on cancer history. However, it is thought that conducting analyses by controlling such participant characteristics in these correlational studies will reveal more accurate findings. For example, depression and anxiety levels can differ in metastatic and non-metastatic breast cancer patients, and different factors can affect these psychological symptoms (20). Therefore, it is recommended to obtain information about these two characteristics and control for them in future theses.

When the methodology was examined, descriptive and cross-sectional studies were predominant. Following this, there were theses comparing diagnosed and healthy groups. The characteristics of the participants in both groups in these investigations were not equivalent. For example, many characteristics of the participants, such as their ages, education levels, and socio-economic levels should be as similar as possible. In such designs, it is recommended that the groups be similar to each other in order to see the most accurate results of the difference or manipulation (21). The least common research method was scale development and effectiveness studies. Although the number of scales translated into Turkish is increasing, introducing scales that prioritize breast cancer will yield more reliable results. In the reviewed theses, the validity and reliability of the Cancer-Related Thoughts scale (22) and the Self-Evaluation scale (23) were examined in Turkish. In Coşar’s (23) study, the validity and reliability of a previously translated scale was reanalyzed in a breast cancer patient sample and the scale was adjusted according to this group. In this example a scale that can be used in studies involving other breast cancer patients has been added to the national literature. Other important information added to the literature will be produced through effectiveness studies. Three effectiveness studies were included, two online psychological interventions (24, 25) and one face-to-face psychological intervention (26) were described for breast cancer patients and their effectiveness was tested. These three intervention programs are potentially valuable for the national literature, once the findings are validated by other studies. Psychological interventions developed for breast cancer patients are frequently encountered in the international literature (27). In a meta-analysis study by Guarino et al. (28), it was reported that psychological interventions developed for breast cancer are mostly in the cognitive behavioral therapy school and create positive psychological results for patients. The intervention studies examined in the current study were also cognitive behavioral therapy-centered and have achieved effective results. Considering the increasing prevalence of breast cancer (4), it will be beneficial to develop more Turkiye-specific psychological interventions for breast cancer patients and add them to treatment protocols.

The subjects and variables considered most often included post-traumatic growth, anxiety-depression-stress, psychological coping and perceived social support. Post-traumatic growth, in particular, has an important place in psychology literature. Positive psychological changes that occur after a negative experience are seen as important, especially in the psychological treatment of chronic patients (29). The description of the post-traumatic growth characteristics of breast cancer patients in Turkey reveals potentially important findings and can guide experts working in the field. In addition, examining perceived social support by adding it to the post-traumatic growth models of patients diagnosed with breast cancer can be considered as a suggestion for future studies. Another striking element was that positive psychological variables related to the psychological aspect of cancer are frequently investigated in international literature (30). Since the positive psychological growth of individuals is also seen to be related to post-traumatic growth, perhaps examining positive psychology variables (finding meaning, acceptance, awareness) in post-traumatic development models and examining the relationship and effects of these variables with other psychological processes in national studies will reveal important findings.

The current review examined post-graduate theses studies investigating the psychological aspect of breast cancer in Turkey. In the evaluation, it was noted that although the participants included in the theses were breast cancer patients, they were not homogeneous in terms of socio-demographic and medical characteristics. In most of the theses, patients with different disease stages were evaluated together. This limits the generalizability of the results. It is recommended that future studies be structured with more homogeneous participant groups.

In addition, the fact that the scales used in theses are scales adapted for breast cancer patients is another factor that will affect the research findings. Although the validity and reliability of the scales used in the national context are among the sufficient criteria, conducting their validity and reliability with breast cancer patients may reveal more accurate results. In addition, developing culture-specific scales will the quality of findings.

Another suggestion for future studies is consistency in the psychological variables examined in breast cancer. The examined theses generally addressed the relationships between psychological symptoms and post-traumatic growth in relation to breast cancer. When the current literature is examined, positive psychology topics and Third Wave CBT are now associated with post-traumatic growth. Thus, it can be suggested that the literature be expanded with studies examining these variables in Turkey.

A further recommendation for future research is the design of the studies. Cross-sectional and descriptive studies were frequently conducted. In particular, experimental designs and effectiveness studies of psychological interventions, which have been published more frequently in recent years, have attracted attention. Future studies developing psychological interventions and testing their effectiveness in breast cancer patients will be beneficial for both the literature and patients.

One of the strengths of the current study is that it is the first article at the national level to review postgraduate theses examining the psychological characteristics of breast cancer patients. In addition, in the light of the findings, research into identified knowledge gaps will be possible in the future.

Conflict of Interest: No conflict of interest declared by the author.

Financial Disclosure: The author declare that this study received no financial disclosure.