Introduction
Chronic rhinosinusitis (CRS) is defined as a long-lasting (>12 weeks) inflammation of the nasal cavity and paranasal sinuses, characterized by symptoms of nasal blockage/congestion or nasal discharge, possibly associated to facial pain/pressure and a dysregulated sense of smell [1]. CRS is a generic term that may be useful to establish diagnosis, but widely incomplete to define the complexity of differing clinical patterns of the disease.
During the last 40 years, clinicians and researchers have underlined the importance of considering the subjective dimension of diseases to achieve a more global and coherent vision about the patient and the effects of the whole health-care process. This perspective was driven by the clinical necessity to go beyond the limits of ‘disease-centered medicine’ in order to reach a more global perspective of ‘patient-centered medicine’ [2]. In this perspective, any information directly provided by the patients about a health condition and its treatment (defined as Patient Reported Outcomes - PROs) represents a fundamental component of any treatment paradigm aimed to provide a personalized approach [3]. In 1948 the World Health Organization defined “health” as a state of complete physical, mental, emotional, and social well-being and not merely the absence of disease or infirmity [4]. According to it, we must be aware that patients with chronic rhinosinusitis barely fulfill this definition.
In the past 15 years, an expanding body of literature was built on CRS reporting its high socio-economic impact, reduced quality of life (QoL) and direct and indirect costs on societies, as also abundantly underlined in the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) [1]. CRS with nasal polyps (CRSwNP) is relatively common particularly in asthmatics, affecting about 2-4% of the general population [5-7], but with increasing prevalence among unselected asthmatics (7-15%) [8] and up to 50% in patients with severe asthma, particularly those with late-onset eosinophilic severe asthma [9]. The economic and social burden of rhinosinusitis, both acute and chronic, is enormous [10,11]. Costs of medication, hospitalization, physician’s examinations and surgery account only for direct health care expenses, while there is a concurrent and likewise substantial indirect cost from absenteeism, disability and therefore loss in productivity and work performance [12]. Absenteeism and lower quality of life – according to SF-36 and other health-related QoL measures – are linked especially to some forms of rhinitis such as recurrent acute rhinosinusitis (RARS) and CRS both with and without polyps, with also high prevalence (15-25%) of related depression and anxiety [12]. In the USA, rhinosinusitis is in the top 10 most costly health conditions to employers. The current direct costs for the management of CRS are between $10 and $13 billion per year, with the highest direct costs in patients who had recurrent polyposis after surgery. Indirect costs from absenteeism and presenteeism (decreased productivity at work) significantly add to the economic burden of the disease. Overall, in the USA, the total indirect costs related to CRS were estimated to be of $20 billion per year [1].
Moreover, the possible correlation between CRS and asthma can amplify the burden of both conditions synergistically [13]. Widely accepted is indeed the concept of rhinobronchial syndrome [14-16], which has been introduced to highlight the link between upper and lower airways pathophysiology.
In EPOS 2020 [1] a new concept has been emphasized, which is the multidisciplinary approach based on the precision medicine methodology. Precision medicine, that President Obama sustained in his 2015 Precision Medicine Initiative, was defined by him as “a bold new research effort to revolutionize how we improve health and treat disease” [17]. Precision medicine goes beyond the “one-size-fits-all” approach, taking into account individual differences in people’s genes, environments and lifestyles. This concept was widely introduced with the paradigm of the “4-P Medicine”: Prediction, Prevention, Personalization, Participation [18]. The first three Ps were introduced at the beginning of the century, then extended with the fourth one in 2008 by the molecular biologist and oncologist Leroy Hood [19]. This extension has been labeled as “a driving force for revolutionizing healthcare”, since the individual’s participation is the key to put into practice the other three aspects [20].
The same 4P paradigm has been applied to CRS [21-23]. Being a chronic disorder, the primary fact is that medicine cannot cure CRS patients, but it has the duty to improve its course, lower the impact on QoL and on social costs, also by means of predicting – hence avoiding – possible undesirable progression and maintaining wellness (Prevention). Participation is fundamental: it consists in keeping the patient at the core of the treatment plan, encouraging counselling to maintain adherence and compliance. In the whole scenario, as the response to treatment is influenced by several factors, patients stratification is fundamental to set the correct diagnostic and therapeutic path for each. Identifying markers that may be predictive of response means to actualize the concept of target therapy (Precision) and predicting the response to it (Prediction). On the basis of the model adopted for oncological patients, each clinic should establish a multidisciplinary team to plan the correct personalized treatment for CRS patients (Figure 1).