As fear of progression has to be distinguished from anxiety disorders, traditional anxiety measures, such as the State-Trait Anxiety Inventory (STAI; Spielberger et al. 1983) or the Beck Anxiety Inventory (Beck and Steer 1993), cannot adequately measure FoP. During the past few years, several self-report measures have been developed that focus specifically on FoP. Recently, Thewes et al. (2012b) provided a systematic review on all current multi-item self-report questionnaires and subscales that assess FoP in cancer patients. They identified 20 multi-item assessment tools, 6 of which being subscales of more comprehensive instruments. Ten measures were classified into the group of brief instruments with 2–10 items. Most of these measures had only limited reliability and validity data available. The remaining four measures fell into the group of longer tools with more than 10 items. These latter measures were judged as reliable and valid. One of these longer self-report measures that had proven reliable and valid is the Fear of Progression Questionnaire (FoP-Q). Actually, the FoP-Q received the highest total quality rating of all instruments, together with the Concerns about Recurrence Scale by Vickberg (see Thewes et al. 2012b).

The FoP-Q is a multidimensional self-reporting questionnaire that was developed in our research group, using samples of patients who were suffering from cancer, rheumatic diseases, and diabetes mellitus (Herschbach et al. 2005). The questionnaire contains 43 items that are rated on a five-point scale, ranging from never to very often. The items relate to the five dimensions affective reactions, partnership/family issues, occupation, loss of autonomy, and coping with anxiety. The total score is calculated as the sum of the subscales’ mean scores, excluding the coping subscale. The questionnaire (total score) has high internal consistency (Cronbach’s α = 0.95), as well as high test–retest reliability over one week (r _tt  = 0.94) (Herschbach et al. 2005).

Apart from this full version, Mehnert et al. (2006) developed a unidimensional short form, using a sample of breast cancer patients. This abbreviated version, FoP-Q-SF, comprises 12 items pertaining to four of the five subscales (excluding coping). The short form showed adequate reliability (α = 0.87); correlational analyses with other psychosocial measures suggested validity. Furthermore, a version for partners of chronically ill patients has been developed and validated, recently, based on the 12-item short form (Zimmermann et al. 2011).

Moreover, the Fear of Progression Questionnaire was translated into two further languages. Shim et al. (2010) provided a Korean version of the full FoP-Q, based on research with a heterogeneous cancer sample. Kwakkenbos et al. (2012) adapted the short form and developed a Dutch version of the FoP-Q-SF, using a sample of patients with systemic sclerosis. Thus, the FoP-Q and the FoP-Q-SF proved to be applicable and useful measures of fear of progression, or fear of cancer recurrence.

Most researchers acknowledge that FoP is an adequate response to the suffering from cancer that, nonetheless, might become dysfunctional. Therefore, it would be highly desirable to identify patients who experience heightened, clinically relevant levels of FoP. However, to date none of the available self-report measures, including FoP-Q and FoP-Q-SF, provides a validated cut-off for the classification of dysfunctional FoP. One reason for this unsatisfying condition is the lack of established external criteria. To date, we do not have a well-established definition of a clinical state of dysfunctional FoP, analogous to the definition of common mental disorders. Consequently, there is no clinical interview to assess and diagnose dysfunctional FoP. Furthermore, it does not seem appropriate to use one of the common anxiety measures as a gold standard, and to conduct sensitivity and specificity analyses of FoP measures in order to establish a clinical cut-off score. Therefore, most researchers who need to define clinical FoP use cut-off scores that are based on statistical considerations, taking into account the distributional characteristics of the measure. Alternatively, cut-off scores are defined on the basis of theoretical considerations.

This shortcoming of the current state of research on FoP has far reaching consequences. As Thewes et al. (2012b) point out, the lack of diagnostic criteria limits comparison between studies, the development of specific interventions, the evaluation of the criterion validity of measures, as well as the development of screening tools indicative of clinical states of FoP.

Research on FoP in cancer patients has grown rapidly during the recent years, and the research literature has accumulated. In fact, there are already three systematic reviews on different aspects of FoP in cancer (Crist and Grunveld 2013; Koch et al. 2013; Simard et al. 2013), which underlines the massive interest and efforts put on this topic. Most of this research was conducted with breast cancer patients. For instance, only 2 of the 17 articles that were included in the systematic review by Koch et al. (2013) included patients who were not diagnosed with breast cancer. In the most comprehensive systematic review, so far, Simard et al. (2013) included 130 papers. The majority of the studies that they had reviewed focused on a specific cancer site, primarily breast cancer (42 studies). However, research also focused, among others, on patients with prostate cancer, ovarian, hematological, or colorectal cancer. Most of the research on FoP was conducted in the United States, but there are also several studies from the UK, Canada, or Germany (see Simard et al. 2013).

In the following, we will briefly refer to the main empirical results on prevalence and correlates of FoP.