The way the model works is that as you move down the diagram, the focus shifts from the biochemical level to the person as a whole, through to how the person operates as part of the society [8], thereby promoting a holistic and patient-centered approach to outcome assessment. A dimension positioned higher in the diagram underlies the lower dimensions.
As illustrated in Fig. 23.1, characteristics of the individual and the environment can interact with and alter all dimensions of QoL [9]. These characteristics include intrapersonal, interpersonal, institutional, community and public policy factors [9]. Biological function involves basic pathophysiological processes occurring at the molecular, cellular or whole organ levels [9]. Not only can biological function manifest in symptoms, it can also have direct or indirect effects on the other subsequent dimensions of QoL [9]. Symptoms are a person’s somatic sensations. The person’s experience and interpretation of symptoms are major determinants of functional status, general health perceptions and overall QoL [9]. Functional status refers to a person’s ability to perform tasks. It is generally conceived that physical, social/role, emotional/psychological and cognitive functioning are the most pertinent areas of functional status for evaluating QoL [10]. General health perceptions integrate the earlier dimensions, but are more than a mere summary of them. When forming an ultimate judgment or rating of their health, people take all elements that are applicable to their personal context into account (not just those that have been identified in the model), including the relative weighting or importance of each [9]. Overall QoL is based on all of the earlier components, but also incorporates happiness and satisfaction with life, which are very much shaped by the person’s values, preferences and circumstances [9].
Quality of Life Measurement
As explained earlier, QoL is an individual’s or group’s perceived health [5], and the patient’s subjective judgment should be the gold-standard. The measurement of QoL thus involves asking patients to rate their own impression of QoL. Such a questionnaire is termed a “QoL instrument”. Numerous instruments have been developed to date, aimed at assessing different QoL dimensions. There are instruments that concentrate on one dimension, with some instruments focusing on symptoms, some focusing on an area of functional status and so on. However, given that QoL is a multidimensional construct, instruments that only explore one dimension of QoL cannot be conceptually considered true or comprehensive QoL instruments. For example, the Low Anterior Resection Syndrome Score (LARS score) is a five-item scoring system for assessing bowel function after sphincter-preserving rectal cancer treatment [11]. Its scoring is designed to reflect the impact of bowel dysfunction symptoms on overall QoL, but because its scope is limited to bowel dysfunction symptoms, the LARS score does not conceptually qualify as a QoL instrument.
QoL instruments are often classified as generic or disease-specific. Generic QoL instruments are designed for evaluating the combined effects of all health problems that the patient endures, whereas disease-specific instruments are designed for examining the effects of one particular condition or a similar group of conditions. Therefore, disease-specific instruments are more relevant and sensitive to the condition of interest, but generic instruments are more sensitive to comorbidities, and enable comparison of QoL between different condition groups. Depending on the purpose and context of QoL measurement, one type of instrument may be more suitable than the other.
Some of the most commonly used QoL instruments in RC are summarized in Table 23.1. All of these instruments are multidimensional, patient self-administered, and have been validated according to robust psychometric criteria.
Table 23.1
Commonly administered QoL instruments in rectal cancer
Instrument | Type/specificity | Items | Domains/(sub)scales/dimensions | Scoring | Comments |
|---|---|---|---|---|---|
Latest version: version 2 (SF-36v2) | Generic | 36 | Physical functioning Role-physical Bodily pain General health Vitality Social functioning Role-emotional Mental health Health change over past year (reviewed separately from the above domains) | 3, 5 and 6-point Likert scale; item score 1–6. Domain score = sum of item scores transformed into 0–100; norm-based scoring (scored in relation to the general population) is also possible (mean 50, standard deviation 10); 2 standardized summary scores can be calculated (physical component summary and mental health component summary). No single total score. Higher score = better QoL. Health change over past year is a single item that is analyzed when it is of interest. | Most extensively used QoL instrument worldwide. Can facilitate comparison of QoL with the general population in a wide range of countries. Can facilitate comparison of QoL with a wide range of other disease populations. More sensitive to comorbidities, but less relevant and sensitive to rectal cancer than cancer- and colorectal cancer-specific instruments. Interpretation of multiple domains may be complicated. |
Latest version: EQ-5D-5 L | Generic | 6 | Mobility Self-care Usual activities Pain/discomfort Anxiety/depression Self-rated health (reviewed separately from the above dimensions) | 5-point Likert scale; item number 1 (no problems) to 5 (extreme problems). Only 1 item per dimension, and dimension level is the 1-digit item number selected; the digits for the 5 dimensions can be combined to form a 5-digit number profiling the person’s health state (the numerals 1–5 have no arithmetic properties and is not a score but a description of the person’s health). Self-rated health is recorded on a 20 cm, vertical visual analogue scale with the top endpoint labeled “the best health you can imagine” and the bottom endpoint labeled “the worse health you can imagine”, corresponding to the score range 0–100; higher score = better health. | Very succinct, and is thus quick and easy to administer. Can facilitate comparison of QoL with the general population. Can facilitate comparison of QoL with other disease populations. Can facilitate calculation of quality-adjusted life years (QALYs) for economic appraisal of interventions. More sensitive to comorbidities, but less relevant and sensitive to rectal cancer than cancer- and colorectal cancer-specific instruments. Lack of arithmetic properties of dimension level may render interpretation and comparison difficult. |
European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core (EORTC QLQ-C30) [21, 22] Latest version: version 3.0 | Cancer-specific | 30 | Global health status/QoL Functional scales: Physical functioning Role functioning Emotional functioning Cognitive functioning Social functioning Symptom scales: Fatigue Nausea and vomiting Pain Dyspnea Insomnia Appetite loss Constipation Diarrhea Financial difficulties | 4 and 7-point Likert scale; item score 1–7. Scale score = mean of item scores transformed into 0–100. No single total score. Higher score on functional/global health scale = better QoL; higher score on symptom scale = worse QoL. | Extensively used QoL instrument in cancer. Can facilitate comparison of QoL with the general population. Can facilitate comparison of QoL with other cancer populations. Less relevant and sensitive to rectal cancer than colorectal cancer-specific instruments. Because the instrument targets cancer, conceptually, it should not be sensitive to non-cancer comorbidities. Interpretation of numerous scales is complicated. |
European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Colorectal Module (EORTC QLQ-CR38/CR29) [23, 24] Latest version: EORTC QLQ-CR29 (CR38 is the older version) | Colorectal cancer-specific | 29 (on its own) or 59 (with EORTC QLQ-C30) for those with a stoma 28 (on its own) or 58 (with EORTC QLQ-C30) for those without a stoma | EORTC QLQ-C30 scales plus Functional scales: Body image Anxiety Weight Sexual interest (men) Sexual interest (women) Symptom scales: Urinary frequency Blood and mucus in stool Stool frequencya Urinary incontinence Dysuria Abdominal pain Buttock pain Bloating Dry mouth Hair loss Taste Flatulencea Fecal incontinencea Sore skina Embarrassmenta Stoma care problems Impotence Dyspareunia aScale is scored separately for stoma and non-stoma patients | 4-point Likert scale; 1 (not at all) to 4 (very much). Scales scored in the same fashion as EORTC QLQ-C30. | More relevant and sensitive to rectal cancer than generic and cancer-specific instruments. Should always be used with EORTC QLQ-C30 (stipulated by its authors), and as a result may be somewhat lengthy and time-consuming to complete. Because the instrument targets colorectal cancer, conceptually, it (this refers to EORTC QLQ-CR29 alone, and not EORTC QLQ-C30) should not be sensitive to comorbidities or facilitate comparison of QoL with non-colorectal cancer populations. Interpretation of numerous scales is complicated. |
Latest version: version 4 | Cancer-specific | 27 | Physical well-being Social/family well-being Emotional well-being Functional well-being | 5-point Likert scale; item score 0 (not at all) to 4 (very much). Subscale score = sum of item scores transformed into 0–24 for emotional well-being and 0–28 for all other subscales. Single total score (0–108) = sum of all 4 subscale scores. Norm-based scoring is also possible. Higher score = better QoL. | Extensively used QoL instrument in cancer. Can facilitate comparison of QoL with the general population. Can facilitate comparison of QoL with other cancer populations. The single total score is easy for interpretation and comparison. Less relevant and sensitive to rectal cancer than colorectal cancer-specific instruments. Because the instrument targets cancer, conceptually, it should not be sensitive to non-cancer comorbidities. |
Latest version: version 4 | Colorectal cancer-specific | 9 (on its own) or 36 (with FACT-G) | FACT-G subscales plus an additional colorectal cancer subscale | Response scale and item scores are the same as FACT-G. Subscales scored in the same fashion as FACT-G, with the additional colorectal cancer subscale score transformed into 0–28 (the 2 ostomy items in the subscale are not currently scored). FACT-C Trial Outcome Index (0–84) = sum of physical well-being, functional well-being and colorectal cancer subscales scores. FACT-C total score (0–136) = sum of all 5 subscale scores. | More relevant and sensitive to rectal cancer than generic and cancer-specific instruments. The single Trial Outcome Index and total score are easy for interpretation and comparison. Should always be used with FACT-G (stipulated by its authors). Because the instrument targets colorectal cancer, conceptually, it (this refers to FACT-C alone, and not FACT-G) should not be sensitive to comorbidities or facilitate comparison of QoL with non-colorectal cancer populations. The ostomy items are not scored and hence difficult to interpret. |
Rotterdam Symptom Checklist (RSCL) [29] | Cancer-specific | 39 | Physical symptom distress level Psychological distress level Activity level impairment Overall valuation of life | 4 and 7-point Likert scale; item score 1–7. Subscale score = sum of item scores transformed into 0–100. No single total score. Higher score = worse QoL, except for the activity scale, where higher score = better QoL. | Can facilitate comparison of QoL with other cancer populations. Less relevant and sensitive to rectal cancer than colorectal cancer-specific instruments. Because the instrument targets cancer, conceptually, it should not be sensitive to non-cancer comorbidities. Not as commonly used as some other cancer-specific instruments like EORTC QLQ-C30 and FACT-G. Consequently, although it can facilitate comparison of QoL with the general population, the reference values are not as well established. |
QoL instruments allow standardized quantification of QoL that can readily support treatment decision-making, evaluation and follow-up, in both clinical research and routine practice contexts. Apart from established QoL instruments, qualitative methods are also used to assess QoL at times, and could elicit information that is not captured quantitatively. However, qualitative methods are more difficult to standardize, and the interpretation and application of such results are more complex and laborious. Qualitative methods are hence not as practical and sustainable as quantitative QoL instruments in measuring QoL.
Response Shift Phenomenon
Most clinicians have probably encountered patients who state that they appreciate life even more after surviving a cancer diagnosis. In general, patients who experience life-threatening diseases often change their internal benchmark and reconceptualize “good QoL” over the disease trajectory to accommodate their illnesses [30, 31]. Furthermore, during the course of RC, many patients adapt to their new situation, and learn how to cope with pain, fatigue, bowel-, urinary- and sexual dysfunction and so forth. Consequently, reports of QoL improving in RC patients over time to a level even superior to baseline, and reports of RC patients having better QoL scores than a comparable group of the general population, are not uncommon. On the contrary, some patients may find a relatively stable situation (by objective standards) increasingly distressing, especially if an expected improvement does not occur. Thus, the patient’s rating of QoL may change over time even though no objective change has been observed. This phenomenon is referred to as “response shift”. Response shift should be taken into consideration in longitudinal studies with a follow-up period of several years, and when comparing QoL of RC patients with the general population [32].
Interpretation of Quality of Life Results
Changes in QoL scores over time and differences in QoL scores between groups can be difficult to interpret. What does, say, an 11-point difference between two groups, or a 7-point improvement in a patient or a group actually mean? Do these numbers indicate a trivial, small, moderate or large difference or improvement? Due to the fact that a statistically significant difference does not necessarily imply that the difference is also of any clinical importance, it is crucial to define what size difference (the minimum difference) is considered clinically relevant. In clinical trials, this should be done a priori.
Some investigators have examined and dealt with this issue by measuring the patient’s perceived extent of change using a “subjective significance questionnaire”, and ascertaining the corresponding difference in EORTC QLQ-C30 scores [33]. Guidelines have been published accordingly in order to support the interpretation of EORTC QLQ-C30 results [34]. Nonetheless, for many QoL instruments, no consensus has been reached regarding this issue, and a clinically relevant difference has not been determined yet. Therefore, no specific guidelines are presented here. Instead, clinicians and researchers working with a specific QoL instrument are encouraged to search the literature for the most up to date evidence within this field in order to base their sample size calculation, analysis and interpretation of results on the most recent knowledge.
Population-based normative or reference values can be useful when interpreting QoL results. These values represent the QoL level of the general population. Thus, reference values assist in the interpretation of QoL data in clinical cancer trials by providing estimates of the QoL level one would expect for a group of patients, had they not been sick. Furthermore, reference values can offer further information regarding the distribution of scores for each scale, and thereby facilitate sample size calculations. Given that it is well documented that QoL is influenced by age and gender, reference values should be age- and gender stratified [35]. In studies where QoL is compared between patients grouped by gender or age, reference values can help to clarify whether differences observed are related to the disease or simply reflect unspecific differences normally found in the general population.
Reference values have been published for a number of QoL instruments (please see the “Comments” column in Table 23.1).
Quality of Life After Rectal Cancer Surgery
During the past decades, numerous studies have shown that essentially all QoL dimensions are affected during the first year after surgery compared with general population norms, with the greatest differences observed at the time of discharge from hospital. Six months postoperatively, global QoL and pain approximate norm reference, but patients still fare worse in physical-, role- and social functioning, as well as being more affected by symptoms and problems like fatigue, dyspnea, insomnia, constipation, diarrhea and financial difficulties [36–38]. However, in general, descriptive cross-sectional and longitudinal studies among RC survivors have concluded that long-term overall QoL after treatment is good [36, 39, 40].
Nevertheless, a few problems persist to be common and bothersome for many years after the initial treatment for RC, affecting several dimensions of QoL. Bowel-, urinary- and sexual dysfunction are issues that continue to trouble RC patients for some years after the initial treatment [41]. Therefore, these issues are described in further detail below.
Factors known to influence the prevalence and severity of bowel-, urinary- and sexual dysfunction are age, gender, tumor level and stage, type of surgery and neoadjuvant therapy [42–49].
Bowel Dysfunction
Recent studies have reported that 50–90 % of RC patients undergoing the sphincter-preserving surgical procedure low anterior resection (LAR) suffer from at least some degree of bowel dysfunction postoperatively [50, 51]. Many patients suffer from a range of bowel dysfunction symptoms including fecal incontinence, urgency, frequent bowel movements and clustering, which are collectively referred to as (low) anterior resection syndrome (LARS or ARS) [11, 52]. The risk of bowel dysfunction mainly depends on tumor level and height of anastomosis [53].
In a recent study of LARS using the aforementioned LARS score, the authors found that out of 183 patients who underwent sphincter-preserving resection, 29 % had “no LARS”, 25 % “minor LARS” and 46 % “major LARS” at 12 months after surgery [54]. They also found that the syndrome had a considerable impact on the patient’s everyday life, and was associated with impairment in several QoL dimensions. Studies have shown that bowel dysfunction undermines mental health, social- and physical functioning, and that fecal incontinence is associated with poorer levels of lifestyle, coping, depression and embarrassment [41, 55, 56]. In a cross-sectional study of 81 RC patients with no stoma, bowel dysfunction was shown to be negatively associated with global QoL, physical-, role- and social functioning [57]. In two recent studies, one being a follow-up study of 260 non-stoma patients and the other a cross-sectional study of 796 non-stoma patients, global QoL, fatigue, insomnia, physical-, role-, emotional- and social functioning were shown to be strongly associated with LARS [54, 58]. Moreover, the latest follow-up of patients in the famous Dutch total mesorectal excision (TME) trial using the LARS score revealed that 46 % of the surviving cohort experienced “major LARS” even more than 14 years after treatment, which was also associated with poorer QoL in a number of dimensions [59].
Even though LARS is undoubtedly highly prevalent, it has previously been poorly defined and hence inconsistently measured and reported. Consequently, prevalence estimates of LARS vary significantly between studies. Novel tools that have been rigorously developed and validated for international use, like the LARS score [11, 60] and the Memorial Sloan-Kettering Cancer Center (MSKCC) Bowel Function Instrument [61], enable standardized assessment of LARS across centers and borders, and will hopefully facilitate valid comparisons of results and meta-analysis on the subject in the future.
Patients with a permanent stoma after RC surgery also suffer from problems related to bowel and/or stoma dysfunction. Stoma formation through the rectus muscle is complicated by parastomal herniation in up to 50 % of cases, and this is a distressing problem that reduces the QoL of stoma patients [62, 63]. Leakage of stools, need for frequent bag-changing, stoma care-related problems, sore skin, odor and noise from the stoma, embarrassment and travel challenges are issues commonly reported by patients, affecting several dimensions of QoL [38, 64–66].
Urinary Dysfunction
Urinary dysfunction is common after RC treatment and consists of urinary urgency and incontinence, increased frequency of urination, incomplete bladder emptying and urinary retention [41, 45]. Urinary dysfunction has been demonstrated to be associated with worse social functioning and more pain [41].
In the Dutch TME trial, urinary dysfunction was investigated in 785 patients 5 years after surgery. Long-term incontinence was reported by 38 % of patients, of whom 72 % had a normal preoperative function. Long-term difficulty in bladder emptying was reported by 31 % of patients, of whom 65 % had a normal preoperative function. The authors concluded that urinary dysfunction after RC treatment is mainly caused by autonomic nerve damage during surgery, and found that preoperative radiotherapy was not associated with urinary dysfunction [45, 46], which is similar to the conclusion of a recent systematic review and meta-analysis on the topic [67].
Sexual Dysfunction
Sexuality is a key part of adult QoL. Even though sexual activity declines with age, and the median age of RC patients is around 70 years, the majority of RC patients are sexually active prior to the treatment of their disease [68]. Sexual problems after surgery for RC are common. They are multifactorial, inadequately discussed, and often untreated. Nevertheless, the impact of RC treatment on sexual function is poorly investigated, and the majority of existing studies are limited by low response rates, especially among women, indicating that the issue is still taboo [40, 67].
Specific sexual problems in women are dyspareunia, reduced libido, arousal, lubrication and orgasm. Whereas in men, these are impotence, decreased libido, orgasm and ejaculation [56, 57]. The reported rates of sexual dysfunction vary significantly, ranging from 23 to 69 % in men, and from 19 to 62 % in women [69]. In a study involving 180 patients undergoing curative RC surgery, 29 % of women and 45 % of men reported that “surgery made their sex lives worse” [70].
An unusually high response rate (>75 %) was obtained in the Dutch TME trial. Only patients who were sexually active before RC treatment (79 % of male patients and 52 % of female patients) were evaluated (n = 757). Results showed that general sexual dysfunction, erectile dysfunction and ejaculation problems were reported by 76, 80 and 72 % of male patients, respectively. In female patients, increase in general sexual dysfunction, dyspareunia and vaginal dryness were reported by 62, 59 and 57 %, respectively. Two years after treatment, 29 % of men and 18 % of women were no longer sexually active [68].
Another study of 457 RC patients revealed that male RC survivors had more problems with erectile function (54 %) than males in the general population (27 %). Furthermore, 68 % of male RC survivors reported ejaculation problems. Lubrication problems and dyspareunia were more common in female RC survivors (35 and 30 %, respectively) than females in the general population (5 and 0 %, respectively). Male RC survivors scored lower on the EORTC QLQ-CR38 sexual functioning scale compared with the general population. However, scores on the QLQ-CR38 sexual enjoyment scale were similar between the two groups. Female RC survivors reported worse sexual functioning as well as less sexual enjoyment than the general population. For both genders, the differences in sexual functioning and/or sexual enjoyment identified were clinically meaningful [43].
Sexual dysfunction is significantly more severe in men, and men feel more distressed by it than women. Sexual function has been shown to be impaired in all age groups, but younger patients have a more severe impairment of sexuality, which leads to profound emotional symptoms. Strain due to impaired sexuality is significantly higher for patients aged ≤69 years compared with older patients [48, 71].
Although many studies have documented that a large proportion of RC patients experience sexual dysfunction after their treatment, it is still not entirely clear how to define the presence of sexual dysfunction, sexual problems and sexual disorders, and thus estimates vary across studies. Furthermore, studies within this taboo field are compromised by low response rates, especially among women. Hopefully, the increasing attention on these very important matters will lead to more high-quality research in the future.
Quality of Life with or Without a Permanent Colostomy
The presence of a permanent stoma has historically been viewed as a factor that reduces QoL. Therefore, it is thought that preservation of bowel continuity would be superior to the formation of a permanent stoma whenever the oncological outcome is deemed equivalent [51]. With the introduction of stapling devices and improved surgical techniques, permanent colostomy rates have decreased, and anastomoses are now performed at very low levels.
As discussed earlier, it is evident that a large proportion of non-stoma patients suffer from severe bowel dysfunction, which affects their QoL substantially [54, 58]. In addition, stoma care has improved considerably during the past decades, both with respect to available products and to the information and guidance provided by specialist nurses. When taking all of these factors into account, the superiority of sphincter preservation does not appear as definite as once believed. Thus, many studies have investigated the QoL of RC patients after LAR versus abdominoperineal resection (APR).
A Dutch study published in 2014 examined the physical and mental consequences of a stoma among 1019 RC survivors 1–10 years after diagnosis. They found that stoma patients reported statistically significant lower global health status/QoL, physical-, role- and social functioning, but fewer problems with constipation and diarrhea compared with those without a stoma. All differences were of small clinical relevance [72].
In a Cochrane review updated in 2012, the authors concluded that there is no clear difference in global QoL with or without a permanent stoma [73]. The results of 35 studies, all non-randomized and representing 5,127 participants, were analyzed in the review. In 14 out of the 35 studies, the authors found that patients undergoing APR/Hartmann’s operation did not demonstrate worse QoL than patients undergoing LAR. The remaining studies identified some differences, but these were not consistently in favor of non-stoma patients. Amongst the included studies, there was a clear tendency towards stoma patients reporting significantly more sexual problems, but less diarrhoea and constipation compared with non-stoma patients. Therefore, no firm conclusion was drawn, but the authors stated that “the included studies challenge the assumption that anterior resection patients fare better” [73].
Similarly, in a meta-analysis of 1,443 patients from 11 studies, no difference in global QoL was found. Nevertheless, stoma patients showed superior future perspective, cognitive- and emotional functioning scores than non-stoma patients, while non-stoma patients tended to score more positively on vitality, sexual- and physical function [74].
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