Due to the demanding and prolonged nature of medical treatments, approximately 30% of cancer patients experience psychological issues, including depression, anxiety, and adjustment disorders [1–3]. Among individuals with chronic illnesses like diabetes and Parkinson's disease, as well as cancer patients [4], a prevalent concern is the fear of progression (FOP). FOP is a natural response to factors such as medical treatment, illness duration, and the diagnosis itself. However, when FOP reaches high levels, it can become dysfunctional and have clinical implications [2,4]. In the case of cancer patients, FOP primarily revolves around the fear of cancer metastasis and progression, leading to emotional, behavioral, and cognitive challenges [2,5]. It is important to note that there is another related fear known as fear of cancer recurrence (FCR), which can be used interchangeably with FOP. However, FCR tends to be more prevalent among cancer survivors or those in the early stages of cancer, whereas FOP is more prominent among patients in the advanced stages who are concerned about the possibility of cancer progression. Nevertheless, it is worth mentioning that FOP is experienced by cancer patients at all stages [2,6].
According to previous research, on average, 50% of cancer patients experience fear of progression (FOP) within several years following cancer diagnosis [7]. FOP encompasses concerns related to various aspects of life, such as physical well-being, economic stability, family dynamics, work performance, sexual life, and even mortality. FOP differs from psychological anxiety in several ways. In the case of chronic illness patients, particularly those undergoing cancer treatment, FOP arises from genuine concerns related to a real stimulus (their illness). Their response to this stimulus is considered appropriate, as it is a natural reaction to the challenges they face. However, when FOP reaches high levels, it can become dysfunctional and interfere with their overall well-being. Therefore, it is important to utilize specific tools to assess FOP and offer improved support and appropriate interventions in oncology settings [7,8]. There are various valid and reliable tools to evaluate similar concepts to FOP, such as the European Organization for Research and Treatment of Cancer Recurrence Subscale (EORTC-RS), Fear of Recurrence Subscale (FRS), and Fear of Recurrence of the cancer problems in living scale (FRS-CPILS). Among them, the Fear of Progression Questionnaire – Long Form (FOPQ-LF) and Fear of Progression - Short Form (FOPQ-SF) are the most recommended tools and have been widely used in plenty of research works [9]. In the related literature, there are also studies that have evaluated the correlation between FOP and psychological factors, which is done through using FOPQ-SF to estimate FOP [10]. Additionally, a significant association between FOP and factors such as intrusive thoughts, hyperarousal, avoidance, post-traumatic stress, and other anxiety disorders have been addressed in the literature as well [11–13].
Individuals' reaction to any kind of fear is influenced by their religious beliefs, lifestyle, and culture [12]. Consequently, it is important to translate the FOPQ-SF questionnaire into other languages to effectively evaluate FOP. This can be beneficial in understanding patients' coping mechanisms, reactions, and approaches to reducing FOP in different cultural contexts. A survey of the literature reveals that various versions of the FOPQ-SF (such as Malaysian, Chinese, and English) have been validated among cancer patients [11–17]. These studies have demonstrated high test-retest and internal reliability, with supporting evidence for convergent, divergent, and discriminant validity. Furthermore, most of these studies have confirmed a one-factor structure [3,12,14,17].
The presence of studies on fear of progression (FOP) in Iran, which could enhance the care of cancer patients, is currently limited. Translating and validating the FOPQ-SF in Persian would contribute to improving the literature on FOP in Iran, providing researchers and clinicians with a valuable foundation for future research. While a valid FOPQ-LF [18] is already available in Iran, both FOPQ-LF and FOPQ-SF have been proven effective in accurately assessing FOP. However, FOPQ-SF offers greater feasibility and ease of completion for cancer patients [9]. Furthermore, in contrast to the FOPQ-LF, the FOPQ-SF includes a cut-off point of 34. This feature facilitates the evaluation of elevated and clinical FOP in cancer patients, enabling clinicians to provide timely and appropriate interventions [11,19]. Additionally, although a study has assessed the Cronbach's alpha of FOPQ-SF [20], comprehensive information on its various validities and factor structure in the Persian context is lacking. Therefore, this study aims to establish the reliability, validity, and factor structure of the Persian version of FOPQ-SF.