Breast cancer (BC) is the most common malignant tumor and one of the top causes of cancer-related death worldwide (Sung et al., 2021). The recent advances in early tumor diagnosis coupled with more effective treatment strategies resulted in a steady increase of long-term survivors (Nardin et al., 2020; Invernizzi et al., 2022). These improved survival rates led to a significantly higher incidence of disabling complications related to breast cancer and/or its treatment (Invernizzi et al., 2020a; D’Egidio et al., 2017; Zhong et al., 2020). These conditions have detrimental effects on patients’ health status, leading to a high burden of psychological suffering, functional impairment, and reduced health-related quality of life (HRQoL) (Sunilkumar et al., 2021). Not dissimilarly from the tumor, the diagnosis and treatment of survivorship issues require a precision medicine approach (Ballinger et al., 2021).
Only recently HRQoL became an integral part of the healthcare system and component of modern treatment strategies and translational studies design (Cheng et al., 2017). The ability to precisely assess and define HRQoL determines the success of oncological rehabilitation interventions in breast cancer (Rick et al., 2017). During the past few years, our research groups promoted a paradigm shift for the management of HRQoL issues in breast cancer survivors. This approach, both for translational research and clinical practice, is biomarker-based, akin to that for the management of the neoplasm itself (Pagni et al., 2019; Criscitiello et al., 2022; Pal et al., 2021; Fusco et al., 2021). In particular, we identified relevant subclasses of patients that could benefit from targeted rehabilitation strategies among the major HRQoL issues in breast cancer survivors. We focused our attention on breast cancer-related lymphedema (BCRL) (Invernizzi et al., 2018; Invernizzi et al., 2019; Michelotti et al., 2019; Invernizzi et al., 2020b; de Sire et al., 2021), axillary web syndrome (de Sire et al., 2020a), cancer treatment-induced bone loss (Venetis et al., 2021; Invernizzi et al., 2020c), aromatase inhibitor-induced arthralgia (Grizzi et al., 2020; de Sire et al., 2020b), and cancer related fatigue (Invernizzi et al., 2020d). More in detail, BCRL (i.e., localized retention of lymph, interstitial fluids, and proteins in the subcutaneous tissue of the upper limb after axillary dissection and/or radiation treatment) is an extremely disabling and progressive condition that affects ∼20% of breast cancer survivors (Gillespie et al., 2018). Recently, single nucleotide polymorphisms in ctDNA have been documented in BCRL patients, suggesting a possible role for individual predisposition in the development of BCRL (Hadizadeh et al., 2018; Smoot et al., 2017). These genes include lymphangiogenic and angiogenic genes (e.g., LCP2, NRP2, NFKB2), pro-inflammatory (e.g., IL1, IL2, IL8, IL17, NFKB2) and anti-inflammatory (e.g., IL4, IL10, IL13) cytokines, connexins, and potassium channel genes (e.g., KCNA1, KCNJ3, KCNJ6, KCNK3). Of note, specific biological characteristics of the primary tumors (e.g., laterality, lymph-vascular invasion, and extracapsular extension of the lymph node metastasis) can be employed as risk indicators (Invernizzi et al., 2018). Another major health issue in breast cancer survivors is persistent pain after the surgical procedure, which involves almost 30% of patients (Chang et al., 2021). In this condition, the inflammatory milieu is responsible for the peripheral sensitization and inflammatory pain hypersensitivity at inflamed sites, particularly nerves. The role of inflammasome and circulating biomarkers have also been explored in cancer related fatigue, one of the most burdensome and long-lasting side-effects of breast cancers (Vannorsdall et al., 2021). Despite circulating C-reactive protein and IL6 seem to be associated with an increased risk of CRF in long-term breast cancer survivors, these inflammatory markers are not yet ready to enter the clinical practice (Maurer et al., 2021).
The results of our studies provide strong evidence that under the umbrella of “quality of life interventions” stand a multitude of different conditions that are extremely heterogeneous in their biology, even in the presence of the same clinical manifestation. For this reason, individualized therapeutic approaches are required for the management of these conditions at a single-patient level. To achieve this goal, however, a multidisciplinary approach is required. We believe that the breast cancer healthcare community is ready for the “quantum leap” of implementing biomarkers for the clinical management of survivorship issues. Indeed, all these conditions are related not only to the active therapeutic oncological treatments but also to the tumor itself, which hinders cancer patients’ HRQoL. Thus, the concept of “quality of life interventions” should be expanded to the concept of Cancer Rehabilitation, which comprises a framework of distinct approaches, from different points of view, and by different specialists.
In conclusion, thanks to the increasing effectiveness of screening programs and treatment schemes, the number of women who die of breast cancer has gradually declined. In this scenario, the prolongation of patients’ life is no longer sufficient. Indeed, caregivers are now required to preserve and improve the HRQoL of patients. The next-generation model of “breast cancer survivorship” starts with the initial diagnosis and extends through the rest of the patient’s life according to patient-specific (and in some cases tumor-specific) biological characteristics (Duijts and Spelten, 2021; Chan et al., 2021). This complex and fascinating field requires dedicated translational research studies and clinical trials to be fully integrated into clinical practice.