Introduction

Having any type of cancer involves the possibility of death, accompanied by pain, loss of independence, and decreased self-esteem (^{Rouhani & Holland, 2003}). Breast cancer is the most common oncologic pathology in women worldwide, with over two million diagnoses estimated in 2018, accounting for 11.6% of all cancers. In Mexico, the incidence of breast cancer in women has increased in recent decades, and in 2018 it ranked first with 26%, followed by thyroid cancer with 9.7%, and cervical cancer with 7.5% (^{GLOBOCAN, 2019}).

A person’s ability to cope with a cancer diagnosis and treatment varies according to the evolution of the disease and depends on medical, psychological, and social factors such as medical care, the characteristics of the disease (clinical evolution, site of onset, type of treatment), previous level of adaptation to the condition, prognosis of the disease, management of losses suffered in one’s lifetime, emotional support, personality traits, coping mechanisms, cultural, spiritual, and religious environment, and the possibility of physical and psychological rehabilitation (^{Massie & Greenberg, 2019}).

According to ^{Saavedra and Villalta (2008a)}, resilience proposes an explanatory hypothesis of healthy behavior in adverse or high-risk conditions. It is a personal trait, constituted on the basis of the early bond and cultivated throughout the history of the subjects, enabling them to appropriate life events. For ^{Rutter (2012)}, resilience can be defined as a reduced vulnerability to risk experiences, overcoming a stressor or adversity, or a relatively good outcome despite experiences of risk. It is therefore an interactive concept in which the presence of resilience must be deduced from individual variations in the outcomes of those who have experienced a significant stressor or adversity.

It is currently thought that resilience also plays an important role in the experience of adverse or traumatic events, such as disease process. The work of ^{Grotberg (2003)} in The International Resilience Project 2003-2005 proposed a resilience model based on the possession of three resources expressed as follows: “I am,” “I have,” and “I can.” Although Grotberg states that, for her conceptualization of resilience, not all the resources mentioned are required, the presence of only one of them does not suffice: in other words, resilience is the result of the combination of these three resources. These resources provide an idea of how the subject appropriates reality and opens up the possibility of a healthy behavior or overcoming traumatic events.

Based on the above, ^{Saavedra and Villalta (2008a)} take up the notion of the resources raised by ^{Grotberg (2003)} and add the history of the subject, on the assumption that the way each person interprets and acts in the face of problems recurs throughout their lifetime. Accordingly, for these authors, a resilient response is an action characterized by an evaluation of the cognitive and affective elements of the problem that arise from a system of beliefs and social ties that provide security. These authors created a resilience scale, which proved to be valid and reliable for the Chilean general population (^{Saavedra & Villalta, 2008b}).

The interest in studying these issues stems from a repeated observation in clinical practice: women who seek oncology services - regardless of their economic, social or environmental conditions - react to and cope with the diagnosis in very different ways, which, in some cases leads to the presence of depression and/or anxiety. But what are the individual differences that lead women with breast cancer to produce maladaptive psychological responses that can lead to the development of a psychiatric diagnosis? One possible answer is resilience, which has been studied in a medically ill population because the loss of physical health is considered an adverse event in life related to psychological processes. Previous studies in other countries (^{Alcalde, Alcalde, & Palacios Banchero, 2011}; ^{Becoña Iglesias, 2006}; ^{Benvenuto Haase, 2015}; ^{Moscoso-Escalante & Castañeda-Chang, 2018}; ^{Retiz Flores, 2016}) show that valid, and reliable resilience measurements do exist. One of the main strengths of the SV-RES scale is that it addresses the different components of resilience, rather than adopting a one-dimensional perspective, as has traditionally been the case in studies with medically ill populations using the Resilience Scale created by Connor-Davidson (CD-RISC; ^{Connor & Davidson, 2003}; ^{Markovitz, Schrooten, Arntz, & Peters, 2015}; ^{Matzka et al., 2016}; ^{Min et al., 2013}; ^{Sharpley, Bitsika, Wootten, & Christie, 2014}).

Although the SV-RES scale was created and validated in a Spanish-speaking and Latin American population, it is necessary to evaluate its psychometric characteristics to determine whether it is useful for the sample in this study and could therefore be included in the broader research of which it formed part. In this respect, ^{Reyes-Lagunes (2011)} states that when a scale has been designed in a different cultural environment, it is essential to know its structure in the new context. The objective of the present study is therefore to appreciate the different components of resilience proposed through the SV-RES Scale in a sample of Mexican women with breast cancer diagnosis.

Method

Results

A total of 114 women diagnosed with breast cancer were included. The average age was 54.42 years, with an age range of 33-94 (SD 10.14 years). The average number of years of schooling of the sample was 8.44 (SD 3.78 years). Over a third of the women (36.9%) had some type of occupation involving financial remuneration, whether self-employment, part-time, or full-time, work.

Regarding the clinical variables, 56% were at an early clinical stage (in-situ cancer until clinical stage IIA) and, at the time of the evaluation, were undergoing chemotherapy-based treatment (81.6%) or surgery (69.3%).

Discussion and conclusion

The SV-RES scale is a valid, reliable instrument for assessing resilience in Mexican women with breast cancer. The overall internal consistency obtained was extremely adequate (Cronbach’s alpha = .97) and coincides with that reported by the authors of the original instrument (Cronbach’s alpha = .96) (^{Saavedra and Villalta, 2008a}), and is similar to that obtained by ^{Lerma et al. (2019)} in Mexican patients with chronic renal failure undergoing hemodialysis (Cronbach’s alpha = .96) and higher than that reported in the Mexican Resilience Scale (Cronbach’s alpha = .93) (^{Camacho Valadez, 2016}).

The factor structure obtained in this study was different from the original proposal, with seven factors being obtained instead of the 12 identified by the authors, which jointly explained 72.7% of the variance. These differences may be due to sociodemographic factors. For example, the original validation was carried out in the general population (men and women) aged between 15 and 65, whereas our sample consisted solely of women with oncologic pathology. We also consider that the grouping of items into certain factors may be related to their cultural understanding; for example, item 17: “I am a person with goals in life,” which was originally located within the “Pragmatism” factor is grouped under the “Identity” category here.

The most consistent items were those related to problem solving, emotional ties and future projection. These results were consistent with similar research on breast cancer patients. For example, ^{Ocampo et al. (2011)} showed a positive, significant correlation between breast cancer patients and the dimensions of social support, strength, meaning of life, and identity. There is also evidence to suggest that individuals with greater resilience have certain characteristics such as adequate reality checks, greater tolerance of negative emotions, a strong capacity for self-reflection, and a great sense of responsibility (^{Vanderpol, 2002}), essential to understanding the emotional response to the disease and its treatments.

As a self-applicable instrument with adequate reliability for clinical practice and research on the oncological population, it is useful for determining the psychological resources women have such as resilience.

A limitation of the present study is that the cultural adaptation of the items in the SV-RES scale was not carried out in the general Mexican population, but with two focus groups: one with experts in oncology and the other comprising women with breast cancer. Another limitation is related to the selection of participants, which was based on a non-probabilistic sample of women attending a specialized care center in the south of Mexico City. Lastly, although the sample obtained was enough to conduct the exploratory analysis, it was not possible to obtain the confirmatory analysis due to the limitations indicated by the ^{Green (1991)} model, which remains pending for future research.

These findings should be viewed with caution before extrapolating them to all Mexican women with breast cancer. However, educational attainment and the proportion of women with paid work in our study sample are similar to that of the national population (42.2%) (^{Instituto Nacional de Estadística Geografía e Informática [INEGI], 2019}; ^{Organización Internacional del Trabajo, 2014}; ^{Secretaría del Trabajo y Previsión Social, 2019}).

Regarding future implications for resilience research, it is essential to identify the factors that will make it possible to homologate its conceptual definition and standardize evaluation measures - even longitudinally. Likewise, it is necessary to promote research on resilience and its impact on the health-disease process, as well as the development of care programs that promote resilience as a means of contributing to a more comprehensive management of medical conditions, to improve well-being and quality of life for all individuals.

This is important when considering the clinical implications in which, through a greater knowledge of psychological processes in this group of patients, care programs that promote positive psychology can be implemented –with special emphasis on resilience– to reduce the emotional burden and psychiatric diagnoses and thereby improve the quality of life in women with breast cancer.