The aim of this survey was to assess patient-reported experiences with side effects of mRCC therapies in the real-world setting and evaluate the doctor-patient communication regarding that topic. The demographic data of the 104 participants included in our survey are typical for other collectives described in studies on mRCC and thus seem to represent the common mRCC patient rather well [1]. Moreover, the data are in line with characteristics reported by the German national registry [11].
Our data show that a vast majority of patients receiving treatment for mRCC (89.1%) is suffering from various degrees of side effects, regardless of the type of therapy. Additionally, it can be seen that TKI therapies seem to cause more adverse effects than ICI treatment (98.4% vs. 68.4%; 95%-CI [0.068–0.532]; p = 0.014). This is consistent with findings in the literature on mRCC treatment [2, 6]. The given combination therapies in our survey were rather varied; therefore, the number of participants taking specific combinations was too low to include those into the analysis. However, clinical trials suggest that especially TKI + ICI combinations have a high burden of side effects [7, 12], which makes it even more important to provide adequate information about side effects and how to deal with them.
In our survey, treatment with TKIs was more often associated with gastrointestinal adverse effects such as diarrhea, loss or change of taste, loss of appetite and weight loss than ICI therapies. This is consistent with reports of adverse reactions observed in clinical trials on mRCC treatment [13, 14]. The results show that almost every second patient encountered weight loss; some of them reported severe loss of weight with e.g. 10 kg in 3 months, 20 kg in 9 months or up to 27 kg within the last year. This is alarming as earlier studies have revealed that malnutrition and weight loss may lead to worsening of treatment efficacy [15]. As most patients have not been accurately informed beforehand about potential gastrointestinal side effects, they do not actively try to maintain their weight and might not be aware of the importance of their nutrition [16]. Although these side effects clearly show a need for nutritional counseling, only 6% of the participants of our survey reported that they had received information from nutrition experts. It appears that there is still a need for more nutritional education and support for patients and an improved awareness among physicians of how important this topic is for the patients’ quality of life as well as for therapeutic efficacy. Nutrition experts such as nutritionists and dieticians should be included in the treatment team and nutritional counseling should start right at the beginning of the therapy.
The results also show a high number of patients suffering from fatigue (63%). This is in line with other studies reporting that fatigue is one of the most common symptoms associated with cancer and cancer treatment [17]. However, it seemed that the number of patients reporting fatigue in our survey was higher than in clinical trials leading to the approval of several TKIs. In these studies, the rate of fatigue ranges from 19% (for tivozanib) to 56% (for cabozantinib), with the other TKIs ranging in between [18,19,20,21,22,23]. So far, in almost all RCC clinical trials, adverse event severity has been assessed by the investigator using the National Cancer Institute Common Terminology Criteria for Adverse Events. Sometimes questionnaires for health-related quality of life, such as Functional Assessment of Cancer Therapy Kidney Symptom Index (FKSI) questionnaire and the FKSI–Disease-Related Symptoms (FKSI-DRS), have been added. Unfortunately, there has been no assessment of patient-reported outcomes. However, as earlier trials clearly show, reported adverse events can be affected by the methods used for reporting [24,25,26]. Therefore, there is a great need for including more patient-reported assessments in clinical trials.
In our survey, patients were well aware of the importance of reporting side effects. Nearly 90% mentioned their problems to their physicians. Other studies have reported that direct consultation with the doctor is the primary source of information for cancer patients, followed by other patients, self-help groups and the internet [27, 28]. This is also how the participants in this survey received their information on side effects. Approximately 90% mentioned their physician as being the most important source, followed by booklets and information brochures, the internet or patient support groups. This study clearly shows that even after the consultation with the physician, there is still a need for more or better information and support, which patients try to find by consulting self-help groups or searching the internet. Therefore, it could be helpful if physicians gave out booklets or information brochures for patients to read at home or provided a list of websites containing reliable information.
The majority of participants in our survey was satisfied with the given information on side effects, regardless of where it came from. This is in line with data from other surveys [27, 28]. On one hand, two-thirds of the patients reported that the information they had received regarding the treatment of side effects was well understood and that their questions and problems were adequately dealt with. More than two-thirds could even see an improvement of their side effects. On the other hand, one-third of the participants in our survey did not really understand the information provided and the same number of patients did not encounter any improvement of side effects and therefore continued suffering.
Furthermore, in our survey patients reported that the information on side effects was also scarce when the drugs were first prescribed. Only 19 patients (18.8%) stated that they had received detailed information from their physician; every second patient (49.5%) reported that side effects were mentioned briefly; some (4.0%) stated that they had never heard anything about possible side effects from their care team at all. Therefore, we have to conclude that there is a need for improved doctor-patient communication. When patients are first diagnosed or are given the diagnosis of progression, they are often overwhelmed by the news itself and the amount of information given. Consequently, even if physicians talk about side effects, the patients might not recall those conversations later. Booklets or brochures to hand out to patients could be helpful in that situation. Clearly, more and better information on side effect management should be provided right from the beginning of the therapy. Since living with side effects can seriously impact quality of life, treatment outcomes should not be the only focus of modern therapeutic strategies.