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There are two internationally validated questionnaires currently in use for patients with cancer: the Functional Assessment of Chronic Illness and Treatments ...
Ann Surg Oncol (2009) 16:88–95 DOI 10.1245/s10434-008-0175-9

ORIGINAL ARTICLE – HEALTHCARE POLICY AND OUTCOMES

Validation of the Mexican Spanish Version of the EORTC C30 and STO22 Questionnaires for the Evaluation of Health-Related Quality of Life in Patients with Gastric Cancer Luis F. On˜ate-Ocan˜a1, Alberto Alca´ntara-Pilar2, Diana Vilar-Compte3, Gabriela Garcı´a-Hubard4, Edith Rojas-Castillo2, Salvador Alvarado-Aguilar2, Jose´ F. Carrillo5, Jane M. Blazeby6, and Vincenzo Aiello-Crocifoglio1 1 Departamento de Gastroenterologı´a, Clı´nica de Neoplasias Ga´stricas, Instituto Nacional de Cancerologı´a, San Fernando 22, Me´xico, D.F. 14080, Mexico; 2Departamento de Psico-oncologı´a, Instituto Nacional de Cancerologı´a, San Fernando 22, Me´xico, D.F. 14080, Mexico; 3Departamento de Infectologı´a, Instituto Nacional de Cancerologı´a, San Fernando 22, Me´xico, D.F. 14080, Mexico; 4Facultad de Filosofı´a y Letras, and Histoire et Semiologie de texte et de l’image, Universidad Nacional Auto´noma de Me´xico, and Universite´ de Paris 7 Denis Diderot, Paris, France; 5Divisio´n de Cirugı´a, Instituto Nacional de Cancerologı´a, Mexico City, Mexico; 6EORTC Quality of Life Group and Department of Social Medicine and Clinical Sciences at South Bristol, University of Bristol, Bristol, UK

ABSTRACT Health-related quality of life (HRQL) is a fundamental outcome in surgical oncology and culturally valid tools are essential for this purpose. Our aim was to validate the Mexican-Spanish versions of the European Organization for Research and Treatment of Cancer (EORTC) Quality-of-Life Questionnaire QLQ-C30 and the QLQ-STO22 disease-specific questionnaire module in Mexican patients with gastric cancer (GC). The translation procedure followed EORTC guidelines. Both instruments were completed by patients with GC and analyses were performed within three clinically distinct groups: (1) patients undergoing palliative treatment, (2) patients undergoing treatment with curative intent, and (3) GC survivors. Tests for reliability and validity were performed. One hundred and fifty patients (mean age 54.2 years) completed both questionnaires. Sixty-seven, 55, and 28 patients were allocated to groups 1, 2, and 3, respectively. Compliance rates were high, and questionnaires were wellaccepted. Survivors of treatment for GC reported better functional HRQL scores and lower symptom scores than patients in group 2 who were currently undergoing treatment. Patients selected for potentially curative treatment had better HRQL than group 1 (palliative treatments). Scales in the QLQ-C30 and QLQ-STO22 distinguished Ó Society of Surgical Oncology 2008 First Received: 10 June 2008; Published Online: 1 November 2008 L. F. On˜ate-Ocan˜a e-mail: [email protected]

between other clinically distinct groups of patients. Cronbach’s a coefficients of 14 scales of both questionnaires were [0.7. Multitrait scaling analysis demonstrated good convergent and discriminant validity. Test–retest scores were consistent. We conclude that the Mexican-Spanish versions of EORTC QLQ-C30 and QLQ-C22 questionnaires are reliable and valid for HRQL measurement in patients with GC and are therefore recommended for use in clinical trials of Mexican community.

In Mexico, according to the Histopathology Registry of Malignant Neoplasms, gastric carcinoma (GC) is the fifth cause of all cancer incidences and the second cause of cancer-related deaths.1 GC remains the most common gastrointestinal cancer.1,2 Radical resection is the only curative treatment in GC, but many patients receive adjuvant chemotherapy or chemoradiation or palliative treatments.3 Traditionally, the main outcomes of these treatments comprise overall survival, clinical responses, toxicity profiles, disease-free survival, or even time-to-progression, although these treatments have adverse effects that result in profound deterioration in health-related quality of life (HRQL). Thus, there is increasing interest in the oncology community in the use the HRQL evaluation as an important outcome measurement in some groups of patients with cancer.4 The definition of HRQL continues to be very controversial: a universally accepted definition does not exist to date. However, HRQL can refer to a multidimensional

Measuring Quality of Life in Gastric Cancer

construct that encompasses patient perceptions of both the negative and positive aspects of at least four dimensions: physical; emotional functions; social functions; and disease- and treatment-related symptoms.5 There are two internationally validated questionnaires currently in use for patients with cancer: the Functional Assessment of Chronic Illness and Treatments (FACT-G) and the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30.6,7 These questionnaires have been compared and were found to measure markedly different aspects of HRQL, despite considerable overlap, and were considered noncomparable and even complementary.8 Both core questionnaires possess modules for use in the specific setting of GC: the FACT-Ga and the EORTC QLQ-STO22.9,10 The QLQ-C30 and its QLQ-STO22 disease-specific questionnaire module are used in combination, and these questionnaires are usually selected because they are fully validated, translated into many languages, and adequate for multicultural comparisons.11,12 On the other hand, published information regarding HRQL in the medical literature is scarce in Mexico, and an adequately validated instrument in Mexican Spanish is lacking. Therefore, our aim was to translate and validate the QLQ-C30 and QLQ-STO22 questionnaires in their Mexican-Spanish versions for use in Mexican patients with GC. PATIENTS AND METHODS Patients All patients attending the outpatient clinic of the Gastroenterology Department in the Instituto Nacional de Cancerologı´a (INCan) in Mexico City from January 2007 to September 2007 with gastric endoscopy and a biopsy demonstrating gastric adenocarcinoma were invited to participate in this study. Clinical status of patients was defined according to the Sixth Edition of the Tumor, Node, Metastases (TNM) Staging System of the American Joint Committee on Cancer (AJCC).13 Additionally, clinical status was defined according to the objective of treatment and to the purpose of patient hospitalization in or attendance at the clinic. Patients scheduled for surgery, chemotherapy, or chemoradiation were interviewed during their hospitalization prior to initiation of surgery or chemotherapy. Patients who had surgery, chemotherapy, or chemoradiation after 6 months were defined as the follow-up group, and were contacted during their return visits at the Gastroenterology or Medical Oncology clinics. Exclusion criteria included refusal to participate, presence of concurrent secondary malignancy, inability to understand or complete the questionnaires, and any patient

89

declared with critical illness or acute complication development related with surgery, chemotherapy or chemoradiation. All patients were asked to read and sign the written consent form. Study purpose and safety protection policy were detailed in a printed form accompanying the questionnaires. The research protocol was evaluated and approved by the Institutional Review Board and Ethics Committee of the Institute (registry no. 006/026/GAI). This protocol was supervised by the Quality of Life Group of the European Organization for Research and Treatment of Cancer. The authors have no conflict of interest, and this study was conducted under Psycho-oncology and Gastroenterology Department budgets. Translation and Pilot Testing The Mexican-Spanish version of the EORTC QLQ-C30 questionnaire was previously translated. The translation process of the Mexican-Spanish version of the EORTC QLQ-STO22 was authorized by the EORTC; we followed the official guidelines of rigid forward/backward translation and pilot test.14 We developed an initial proposal of the instrument, which was pilot tested on ten Mexican subjects with GC. Once minor translation difficulties were overcome, we developed the second version, which was tested on ten additional subjects. After these procedures, we proposed the final translated version. This version was revised and approved by the EORTC Quality-of-Life Study Group. Clinical Data Clinical history and physical examination were registered for all patients, along with blood cell count, blood chemistry, basal tumor markers (carcinoembryonic antigen and Ca19–9 antigen) chest X-rays, computed tomography (CT) scan of the abdomen, Karnofsky performance status (KPS) and Eastern Cooperative Oncology Group (ECOG) functional status, TNM stage classification, location in stomach, Lauren type, Siewert type for esophagogastric junction tumors, and treatment group. Analyses were performed, dividing patients into three groups: (1) patients undergoing palliative treatment, (2) patients undergoing treatment with curative intent, and (3) survivors of GC. Instruments The QLQ-C30 (version 3) is comprised of a global health status, five multi-item functional subscales, and several single- or multi-item symptom subscales. Four- to

L. F. On˜ate-Ocan˜a et al.

90

seven-level Likert scales (seven for global health status and four for the remaining scales) were linearly transformed into a 0–100 score, with 100 representing best global health, functional status, or worst symptoms, depending on the measuring property of each multi-item subscale or single-item symptom. The QLQ-STO22 is a 22-item GC site-specific supplemental module designed to augment the QLQ-C30 in terms of sensitivity and specificity for HRQL measurements. This module comprises five multi-item subscales and four single-item symptoms, with higher scores indicating worse symptomatic problems. The original versions in English of both questionnaires have been validated (QLQ-C30 and QLQ-STO22), together with translations into many languages, including Spanish.7,9 Data Analysis Scores for multi-item functional or symptom scales and for single items were calculated by linear transformation of raw scores as described by the EORTC.15 Initially, data analysis was performed independently for QLQ-C30 and for QLQ-STO22 questionnaires. Discriminant validation was evaluated with item convergent validity for each scale assessed employing the correlation between each item and its own scale. Divergent validity was evaluated correlating each item and any other scale. The criterion for success for any item was that the correlation between an item and its own scale was significantly higher than its correlation with any other scale. Correlation assessment between single scores was obtained with the Spearman correlation coefficient (CC), and multi-item correlation of scores was evaluated by the Cronbach a. In addition, clinical validity was evaluated by the extent to which questionnaire scores were able to discriminate between subgroups of patients differing in terms of their clinical status (including KPS, ECOG performance status, body mass index (BMI), blood hemoglobin and hematocrit, serum albumin level, and TNM clinical stage). These differences between groups were tested with oneway analysis of variance (ANOVA), chi-squared, and Kruskal–Wallis tests, as appropriate. Validity was also evaluated comparing the differences of scale scores over time, before treatment and after treatment (repeated ANOVA measurement was utilized to test significance of these changes). Finally, correlation between different QLQ-C30 and QLQ-STO22 scales was explored to demonstrate differences and clinical overlapping. Sample Size Sample size was based on the recommendation of Tabachnik and Fidell, which stipulates that, in order to obtain

reliable estimates through multivariate analysis, the number of observations should be five times the number of variables in the model.16 Thus, for primary scaling analyses a minimal ratio of five patients per questionnaire item was required, i.e., a minimum sample size of 110 patients. Subsets of patients would complete two questionnaires (n = 25 for test–retest). The simple Hill be inflated to allow for some dropout due to disease progression and to analyze results within clinically distinct groups. Any probability value of 0.01 or less was considered significant because of multiple testing. Two-tailed statistics were taken into account in all cases. The SPSS for Windows version 10 software program was employed to perform all computations (SPSS Inc., Chicago, IL, USA). RESULTS Patients One hundred and fifty patients were included in this study; 62 were females (41.3%) with a mean age of 54.2 years [standard deviation (SD) 12.1 years]. During the study period, 67 patients under palliative treatment (44.7%; group 1), 55 patients under active, curative-intention treatment, including those who had undergone the preoperative clinical workup, were selected for neoadjuvant chemotherapy or neoadjuvant chemoradiation (36.7%; group 2), and 28 patients were identified survivors of GC with [6 months of survival after treatment or under longterm follow-up (18.7%; group 3). Relevant demographic and clinical information for all three treatment groups are described in Table 1. One patient declined the invitation to participate during the period of this study, and there were no missing values of individual items. All 150 patients answered both questionnaires, and 25 of these were asked to repeat these after treatment was initiated. The majority of patients completed both questionnaires in \30 min in a quiet environment. Reliability and Validity Results of multitrait scaling analyses are shown in Table 2. The majority of items presented good own-scale correlation, except for the cognitive function scale. An important observation not shown in this table is that the global health/quality-of-life scale is highly correlated with the fatigue scale. Better global health/quality-of-life scores are associated with less fatigue. Moreover, all items on the physical scale (items 1–5) showed significant correlation with the fatigue scale (particularly items 10 and 18; CC, 0.35–0.53).

Measuring Quality of Life in Gastric Cancer

91

TABLE 1 Demographical and clinical information in three treatment groups Group 1 (n = 67), palliative treatment

Group 2 (n = 55), curative treatment

Group 3 (n = 28), survivors of GC

p

27

22

13

Men

40

33

15

0.83

54.2 (12.3)

54.3 (12.7)

53.9 (10.9)

0.98

Socioeconomic group (income) High

Item other-scale correlationsa

Multi-item correlationsb

Global health/ QoL

0.8

0.003–0.56

0.9

Functional scales

Agea (years) Mean (SD)

Item own-scale correlationsa QLQ-C30

Sex Women

TABLE 2 EORTC QLQ-C30 and QLQ-STO22: convergent and discriminant validity of multi-item scales (n = 150)

0.27–0.55

0.01–0.62

0.79

Role

0.66

0.01–0.56

0.8

Emotional

0.41–0.62

0.02–0.47

0.85

Cognitive

0.15

0.004–0.45

0.32

0.7

0.05–0.49

0.8

13

9

2

Intermediate

29

27

13

Social

Low

25

19

13

Symptom scales

3

7

2

Married

47

32

21

Divorced

3

1

14

15

Marital status Single

Other

0.59

Physical

Fatigue Nausea and vomiting

0.49–0.64 0.59

0.004–0.62 0.02–0.5

0.78 0.8

1

Pain

0.45

0.04–0.5

0.55

4

QLQ-STO22

0.22

Multi-item scales

Years of study None

16

7

4

0.04

0.35–0.4

0.002–0.5

0.71

Pain

0.47–0.74

0.04–0.52

0.81

Elementary

25

25

High school

17

13

3

Reflux

0.2–0.36

0.03–0.46

0.59

9

10

10

Eating

0.25–0.5

0.08–0.59

0.74

Anxiety

0.37–0.5

0.01–0.57

0.71

More

11

Dysphagia

KPS 100–80

14

25

21

\80

53

30

7

12.03 (1.9)

13.6 (2.8)

\0.0001

Single items were not included in this table a

Spearman correlation coefficients;

b

Cronbach a

a

Hemoglobin (g/dl) Mean (SD)

11.6 (2.5)

Serum albumina (g/dl) Mean (SD) 3.05 (0.72)

3.29 (0.64)

0.001

3.77 (0.69) \0.0001

Lymphocyte counta (cell/mm3 ) Mean (SD)

1,399 (497)

1,469 (680)

1,518 (606)

0.001

23 (3.9)

28.6 (13.9)

0.001

Body mass indexa (kg/m2) Mean (SD)

22.4 (5)

Clinical stage Ia, Ib, II, IIIa IIIb, IV

5

31

22

62

24

6

\0.0001

As expected, the majority of multi-item-scale and single-item scores of the QLQ-C30 were weakly correlated with those of the QLQ-STO22. Also not surprisingly, correlations between QLQ-STO22 and QLQ-C30 pain scales and anxiety scales were observed. Remarkably, QLQ-STO22 body image scale correlated strongly with QLQ-C30 physical, role, emotional, and social scales (CC -0.52, -0.47, -0.5, and -0.36; p = 0.008; p = 0.017; p = 0.003, and p = 0.075, respectively).

a

Continuous variables; SD standard deviation; p probability value; KPS Karnofsky performance status

Clinical Validity

Regarding QLQ-STO22, the majority of items from the eating scale (items 41–43) presented significant correlations with the dysphagia scale (particularly item 31; CC, 0.4–0.48). Table 2 shows the correlations between scales. The majority of multi-item-scale correlations showed Cronbach a [ 0.7. Only 3 of 14 scales did not presented multi-item correlations [0.7 (cognitive scale from QLQ-C30 and pain and reflux scales from QLQ-STO22) (Table 2).

Comparison of global scores of multi-item scales and single items among the three groups are shown in Table 3, while Table 4 depicts correlations between KPS scores and multi-item scales and single items. Many expected differences among groups and KPS scores were statistically significant. Other relevant clinical parameters were correlated with scores from both questionnaires and are shown in Table 5. Retest was done 117.3 days after original test (SD 97.7). Differences of test–retest score values are described in Table 6.

L. F. On˜ate-Ocan˜a et al.

92 TABLE 3 Known group comparisons. EORTC QLQ-C30 and QLQ-STO22: mean scores (SD) in each group Group 1 (n = 67), palliative treatment

Group 2 (n = 55), curative treatment

Group 3 (n = 28), survivors of GC

p

Global Health/ QoL 51.7 (25.9)

KPS 100-80% (n = 60)

KPS \ 80% (n = 90)

p

76.3 (20)

54.9 (28.1)

\0.0001

QLQ-C30

QLQ-C30 Global health/QoL

TABLE 4 EORTC QLQ-C30 and QLQ-STO22: mean scores (SD) by Karnofsky performance status

70 (25.6) 78.6 (21.3) \0.0001

Functional scales

Functional scales 91 (8.4)

61.8 (23.8)

\0.0001

Role

87.5 (21.8)

53.9 (32.4)

\0.0001

\0.0001

Emotional

82.2 (17.5)

62.1 (27.9)

\0.0001

63.9 (28.3) 73.8 (22.1) 77.9 (25.6)

0.025

Cognitive

91.9 (13.5)

80.2 (22.5)

\0.0001

Cognitive

80.6 (23.7)

90 (15.6) 85.1 (17.2)

0.053

Social

89.4 (20.1)

73 (30.9)

\0.0001

Social

71.1 (33)

82.7 (23.3) 93.5 (14.3)

0.002

Symptom scales

Physical

Physical

64.4 (26.3) 76.9 (19.5) 88.3 (15.5) \0.0001

Role

53.2 (32.7) 72.4 (31.6) 91.1 (16)

Emotional

Symptom scales

Fatigue

18.1 (14.3)

46.8 (24.5)

\0.0001

Fatigue 46.6 (26.7) 28.8 (18.8) 21 (21.2) \0.0001 Nausea and vomiting 34.3 (32.4) 17.9 (25.2) 13.7 (23.6) \0.0001

Nausea and vomiting

12.5 (17.5)

32.4 (33.3)

\0.0001

Pain

13.1 (17.9)

34.8 (24.9)

\0.0001

4.4 (13)

23.7 (27.9)

\0.0001

9.4 (16.3)

37.4 (36)

\0.0001

Pain

37.1 (26.4) 20.9 (20.3) 10.1 (15.3) \0.0001

Single items

Single items

Dyspnea

21.9 (29.9) 13.3 (20.9)

7.1 (13.9)

Insomnia

31.3 (30.6)

Appetite loss

43.8 (39)

Constipation

39.3 (36.7)

Diarrhea

14.4 (24.1) 15.2 (25.5) 10.7 (18.3)

23 (34.5) 20.2 (33.1)

0.045

Dyspnea

0.043

Insomnia

\0.0001

Appetite loss

11.7 (24.4)

43 (40.3)

\0.0001

9.5 (21.9) \0.0001

Constipation

15.6 (26.4)

35.9 (35.4)

\0.0001

Diarrhea

11.1 (21.8)

15.9 (24.6)

0.15

43.9 (34.4)

58.9 (38.4)

0.014

QLQ-STO22

Financial difficulties

Multi-item scales

QLQ-STO22 Multi-item scales Dysphagia 12.4 (14.6)

34.4 (25.5)

\0.0001

Pain

12.2 (13.8)

35.2 (26.5)

\0.0001

Reflux

16.3 (17.2)

29 (24.7)

Eating

14.3 (17.6)

39.9 (25.9)

\0.0001

Single items

Anxiety

29.3 (20.6)

59.5 (26.9)

\0.0001

Dry mouth

41.8 (34.5) 28.5 (36.5) 22.6 (28.8)

Single items

Taste

41.3 (35.8) 23.6 (35.5)

Body image

33.8 (34.6) 32.7 (31.1) 14.3 (24.7)

24.8 (35.8) 23 (29.3)

9.5 (27)

0.86

Financial difficulties 65.7 (37.6) 48.5 (36.7) 30.9 (25.5) \0.0001

Dysphagia

31.7 (25.3) 24.8 (22.8) 12.2 (19.6) \0.0001

Pain

36.8 (26.5)

Reflux

31.2 (26.4) 18.8 (19.5) 16.7 (13)

Eating Anxiety

38.9 (28) 26.1 (24) 14.6 (14.5) \0.0001 58 (28.9) 42.4 (25.8) 31.7 (24.1) \0.0001

Hair loss

20 (21.3) 11.9 (15.7) \0.0001 0.01

0.009

Dry mouth

13.9 (20.6)

46.3 (36.6)

\0.0001

0.011

Taste

12.2 (22.9)

38.1 (38.2)

\0.0001

0.67

Body image

17.2 (24.2)

38.1 (34.5)

\0.0001

Hair loss

43.3 (50)

48.9 (50.3)

3.5 (10.5) \0.0001

49.3 (50.4) 47.3 (50.4) 39.3 (49.7)

0.001

SD standard deviation; p probability values

0.5

SD standard deviation; p probability values; KPS Karnofsky status performance

DISCUSSION There is a need to supplement traditional oncological outcomes with information regarding patients’ views, and HRQL measurements are increasingly being recognized as fulfilling this purpose. Measurement of the patients’ perspective of outcome may guide management or aid treatment evaluation.5 Although GC is very common worldwide, there is a lack of randomized clinical trials with validated HRQL assessments, yet the increasing use of laparoscopic surgery,

adjuvant chemotherapy, or chemoradiation requires full assessment of clinical and patient-reported outcomes.4,17 This study provides evidence that the Mexican-Spanish versions of the EORTC QLQ-C30 and QLQ-STO 22 are clinically valid and reliable and suitable to use in randomized trials, longitudinal studies or other research settings to assess patient health-related quality of life. The findings of this study add additional evidence supporting the crosscultural validity of QLQ-C30 and QLQ-STO22 in other countries with non-English-speaking individuals.

Measuring Quality of Life in Gastric Cancer

93

TABLE 5 EORTC QLQ-C30 and QLQ-STO22: correlation coefficients of scores with some relevant clinical parameters Age

BMI

Hemoglobin

Lymphocyte count

Serum albumin

QLQ-C30 Global health/QoL

-0.002

0.27a

0.22a

0.26a

0.37a

-0.02

0.3a

0.33a

0.18a

0.44a

a

a

0.43a

Functional scales Physical Role

a

0.11

0.21

Emotional

-0.01

0.18

0.02

0.18

0.06

Cognitive

-0.11

0.04

-0.02

0.04

0.03

0.17

0.14

0.06

0.3a

0.07

0.07

-0.24a

-0.24a

-0.28a

-0.33a

-0.14 -0.14

-0.04 -0.29a

a

-0.22 -0.19

-0.18 -0.38a

-0.25a

-0.06

-0.17

-0.25a

Social

0.21

0.21

Symptom scales Fatigue Nausea and vomiting Pain

-0.09 -0.03

Single items Dyspnea

0.02

Insomnia

-0.09

-0.17

-0.08

-0.2a

-0.17

Appetite loss

-0.008

-0.07

-0.15

-0.16

-0.21 -0.09

Constipation

0.06

-0.08

0.05

-0.05

Diarrhea

0.03

-0.06

0.01

-0.09

-0.26a

-0.22a

-0.17

0.11

-0.25a

-0.23a

Financial difficulties

0.03

-0.37a

-0.19

-0.1

-0.31a

QLQ-STO22 Multi-item scales Dysphagia Pain

-0.05

Reflux Eating Anxiety Single items Dry mouth Taste

BMI body mass index;

-0.1

-0.06

-0.18

-0.19

-0.29a

-0.18

-0.11

-0.24a

-0.24a

-0.12

-0.28a

-0.12

0.03

-0.21a

0.05

-0.24

a

-0.03

-0.14

-0.14 a

-0.04

-0.005

-0.13

0.12

Hair loss

-0.29a

-0.21

0.07

Body image

-0.21

-0.19

-0.35 a

-0.19 a

-0.18

a

a

a

-0.27a

a

-0.09

-0.15

-0.13

-0.24

-0.14

-0.1

0.004

probability value \ 0.01

However, it must be stated that, in a recent analysis of an international database, the relationship between overall HRQL and its subdimensions was influenced by the specific culture in which it is evaluated.18 This study supplies important evidence that ethnicity influences perceptions of health and sickness, and that different cultural groups may emphasize different HRQL aspects. Caution is necessary when comparing scores among heterogeneous ethnic groups, but in the majority of cases these differences appear to be relatively minor.19,20 The QLQ-C30 cognitive scale exhibits low convergent validity and multi-item correlation in our study. This observation has been reported in Taiwanese and Thai versions of the questionnaire, as well as in the original version in English.7,12,20

The majority of QLQ-C30 and QLQ-STO22 scores clearly distinguished between other clinically distinct groups of patients. Both questionnaires present important correlation scores with some relevant clinical parameters as well, particularly nutritional status, an observation previously reported by others.21 We have not employed these questionnaires for evaluating the effect of anti-neoplasic treatment on HRQL. However, the performance of different scales may demonstrate that cancer treatment can have some benefits on some scales or symptoms, while being simultaneously detrimental to generic HRQL aspects. The study from Huang et al. showed that, after second-line chemotherapy for advanced GC, patients presented relief in global health/

L. F. On˜ate-Ocan˜a et al.

94 TABLE 6 EORTC QLQ-C30 and QLQ-STO22: test-retest mean scores by clinical stage Stages I, II, and IIIa (n = 10)

Stages IIIb and IV P (n = 15)

Before

After

Before

After

62.5

72.5

56.1

69.4

0.044

Physical

82.7

82.7

74.7

72.0

0.79

Role

71.7

73.3

55.6

61.1

0.64

Emotional

69.2

76.7

66.1

72.2

0.29

Cognitive

93.3

98.3

91.1

86.7

0.95

Social

88.3

91.7

70.0

70.0

0.83 0.84

QLQ-C30 Global health/QoL Functional scales

Symptom scales Fatigue

22.2

25.6

35.6

34.8

Nausea and vomiting 11.7

18.3

24.4

30.0

0.42

Pain

28.3

28.3

27.8

27.8

1.00

13.3 30.0

16.7 13.3

8.89 17.8

13.3 28.9

0.36 0.72

Single items Dyspnea Insomnia Appetite loss

23.3

16.7

35.6

40.0

0.89

Constipation

10.0

13.3

24.4

17.8

0.81

Diarrhea

13.3

16.7

20.0

0.18

Financial difficulties

46.7

50.0

46.7

55.6

0.44

Dysphagia

16.7

10.8

28.9

22.2

0.28

Pain

17.8

21.1

31.8

27.4

0.9

Reflux

12.2

20.7

20.0

0.56

Eating

22.5

22.5

37.2

23.3

0.18

Anxiety

50.0

35.7

49.6

44.4

0.12

Dry mouth

16.7

26.7

40.0

22.2

0.62

Taste Body image

6.67 26.7

6.67 16.7

31.1 22.2

13.3 22.2

0.23 0.51

Hair loss

30.0

70.0

60.0

93.3

0.04

6.67

QLQ-STO22 Multi-item scales

6.67

Single items

quality of life, emotional, and cognitive scales, but not in the appetite scale.22 In conclusion, the Mexican-Spanish versions of both questionnaires are reliable and valid for HRQL measure for patients suffering from GC, and can be utilized in clinical cancer research in Mexican community. ACKNOWLEDGEMENTS We thank the European Organization for Research and Treatment of Cancer Quality of Life Group for their extensive support in the translation and validation procedures of the C30 and STO22 questionnaires. We thank Maggie Brunner, M.A., for her English-language editorial review, as well as Alejandra Garcı´aHubard and Blanca Rosas-Rosas because of their kind support in the logistics of this protocol.

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