Cancer-related fatigue is a distressing, persistent, and subjective sense of physical, emotional, and cognitive tiredness or exhaustion related to cancer or its treatment. It is not proportional to recent activity and interferes with normal functioning [15,16]. According to the National Comprehensive Cancer Network (NCCN) guidelines [16], all patients with cancer should be inquired about symptoms of fatigue at regular intervals during and after treatment. Fatigue management in cancer patients is complex because many factors can contribute to the symptoms. and managing these factors may reduce the symptoms [17]. Relatively limited evidence is available for pharmacological interventions, including psychostimulants, antidepressants, and supplements, whereas non-pharmacological interventions, including psychoeducation, cognitive behavior, and exercise programs, have shown positive and promising results [18–20]. Although many positive impacts on the effect of specific exercises based on cancer type have also been reported, a consensus protocol for exercise is needed. According to recommendations for patients with cancer, aerobic exercise at an intensity of 60%–80% of the maximum heart rate three times a week for 30 minutes or more, moderate intensity exercise for 150 minutes or more per week, or vigorous exercise of 75 minutes or more per week may reduce cancer-related fatigue. Moreover, resistance exercise twice a week for major muscle groups at moderate-to-vigorous intensity can be helpful [21,22]. Multimodal interventions, including exercise combined with other interventions such as high-intensity cardiovascular and heavy resistance training, relaxation, body awareness training, and massage, can also reduce fatigue [16].

Lymphedema is one of the most common complications in cancer patients and a common cause of referral to the rehabilitation department. It is the local or systemic swelling of the body caused by a decrease in the lymphatic transport capacity due to damage or dysfunction of the lymphatic system resulting from lymph node dissection during cancer treatment [23]. Surveilling the incidence of lymphedema in domestic patients with breast cancer for an average of 5 years or more showed that approximately 50% of patients developed lymphedema approximately 6 months postoperatively, and by 3 years, most patients showed symptoms [24]. Therefore, it is important to follow-up on the occurrence of lymphedema during this period as a study reported that postoperative surveillance can reduce the incidence rate [25].

The Korean Society of Lymphedema has published clinical guidelines for evidence-based universal standard practice for lymphedema after cancer treatment [26]. These guidelines recommend complex decongestive physical therapy for the effective treatment of lymphedema. Generally, the treatment comprises an intensive treatment period of 2–6 weeks followed by a management period of several months. Additional intensive treatment may be administered depending on the course of lymphedema. Compression bandages effectively reduce lymphedema, and the effect of treatment is amplified when accompanied by manual lymphatic drainage massage. Professionals recommend compression bandage treatment. The therapeutic effect of compression bandages alone does not significantly differ from that of self-exercise, self-massage, and intermittent pneumatic compression therapy. Therefore, compression bandaging alone can also be considered when considering the economic aspects. A manual lymphatic drainage massage performed by a professional therapist is effective for the treatment of lymphedema, but its efficacy improves with other therapies. Progressive low-intensity exercise does not worsen lymphedema or increase its incidence, yet it improves physical function and QOL. However, the effect of exercise on lymphedema reduction remains controversial.

Radiation fibrosis syndrome (RFS) is another frequently observed complication of radiation therapy [12]. Radiation can damage the spinal cord, plexus, nerve roots, peripheral nerves, and muscles within the radiation field. This is known as myelo-radiculo-plexo-neuromyopathy with multiple clinical symptoms, including progressive myelopathy and plexopathy with gait disturbance due to weakness, shoulder dysfunction, and limited range of motion. The typical neuromuscular symptom is dropped head syndrome, which induces neck extension, weakness, pain, and dysphagia. The most critical role of rehabilitation physicians in the care of RFS is the identification, evaluation, and proper treatment prescription. Currently, this phenomenon cannot be slowed down or reversed. Although the current evidence is limited, supportive care, including physical therapy, medications, and bracing, could alleviate disturbances in patients with RFS [27].

Damage to the peripheral nerve fibers after neurotoxic chemotherapy usually affects sensory nerve fibers, but motor or autonomic neuropathic symptoms may occur depending on the type of anticancer drug. Most agents are neurotoxic in a dose-dependent manner, with either a single high dose or an accumulative dose. If chemotherapy- induced peripheral neuropathy (CIPN) is suspected, the use of taxanes, platinum drugs, vinca alkaloids, thalidomide, and bortezomib should be considered. The drug-specific clinical presentations and neurotoxicity of CIPN are summarized in Table 2 [28]. Moreover, it is crucial to exclude other causes that may lead to neuropathy, including tumor recurrence, para-neoplastic syndrome, atherosclerotic ischemic disease, thyroid dysfunction, and vitamin B12 deficiency [28]. Although these sensory and motor symptoms may be alleviated over time, some may persist long-term, leading to inappropriate proprioceptive feedback, postural control, higher fall risk, and a compromised QOL. As CIPN can continuously produce a significant burden of suffering for cancer survivors, the appropriate management of CIPN is necessary, even if it is very complex and challenging. Unfortunately, consensus on the treatment and prevention of CIPN remains insufficient in the recent guidelines of the American Society of Clinical Oncology [29]. The guidelines suggest that the use of duloxetine may be worthwhile for treatment, but present a relatively conservative recommendation regarding tricyclic antidepressants, gabapentin, and topical gel treatments due to insufficient medical evidence. Notably, various sensorimotor-based exercises can ameliorate CIPN symptoms, thereby improving postural stability. Long-term exercise (≥8 weeks) is also reported to be more effective than short-term exercise. However, additional evidence regarding the exercise protocol is necessary [29].

According to the NCCN, at least 5 years of endocrine therapy is recommended for breast cancer patients if the cancer is hormone receptor-positive from stage 0, the noninvasive stage. Tamoxifen is recommended as the first-line medication for premenopausal patients, whereas an aromatase inhibitor (AI) is recommended instead of tamoxifen in postmenopausal patients over 60 years of age. Otherwise, these drugs are associated with a significantly higher incidence of musculoskeletal problems during treatment. Up to 80% of patients complain of AI-related musculoskeletal symptoms, which comprise a large proportion of patients taking tamoxifen (i.e., approximately 30%). Many even decide to stop taking AI owing to such symptoms, which significantly affects their QOL. The discontinuation of endocrine therapy also increases the risk of cancer recurrence. Therefore, relieving the pain of patients and enabling them to continue treatment are extremely important as they will not only improve the patients’ QOL, but also extend their lifespan.

These symptoms usually emerge 6–8 weeks after AI treatment and may worsen for a year and subsequently stabilize. Symptoms may appear as various forms of pain in the joints, tendons, and muscles. Notably, AI-related musculoskeletal symptoms do not induce neuropathy. Nonsteroidal anti-inflammatory drugs (NSAID) and acetaminophen are reportedly effective in 60%–70% of patients, and additional prescriptions may be considered. A Cochrane review in 2020 stated that the evidence of the effect of exercise therapy on pain, stiffness score, grip strength, health-related QOL score, and adherence to AI is uncertain [30]. However, as several randomized controlled trial studies have reported some positive effects of exercise programs, including aerobic exercise and strength training [31–33], it is also necessary to continuously apply it to patients and establish additional evidence. If the treatments do not harm the patient, it is necessary to accumulate evidence by actively adding potentially beneficial treatments to the comprehensive care strategy.