The EORTC QLQ-C30 questionnaire was used to investigate HRQoL in patients with colon cancer in this population-based study. The major findings of this study were that patients whose planned surgery included a stoma (with/without bowel resection), patients with higher BMI, more comorbidities (ASA status 3 and 4) and smokers were at higher risk of a lower HRQoL than the other included patients. Furthermore, this study showed that patients with colon cancer had worse HRQoL than a Swedish reference population both at baseline and at the 6-month follow-up as indicated by changed scores for 3/5 functional (role, emotional and social), and 4/9 symptom (fatigue, nausea/vomiting, appetite loss and diarrhoea) scales.
It is difficult to compare our findings with those of other studies that used a reference population because these studies vary in methodology and the reference values used (15). However, consistent with our findings, Färkkilä et al. (16), in a study of Finnish patients with colorectal cancer, compared their data with reference data using the EORTC QLQ-C30 questionnaire, and found that pain, fatigue and financial difficulties were the main drivers of poor health. Another study conducted in Germany by Jansen et al. (8) also compared patients with colorectal cancer with control individuals from the general population and showed that diarrhoea and financial difficulties were worse in patients with colorectal cancer.
Several countries have assessed HRQoL in patients with colon cancer, but only one randomized study comparing the effects of open and laparoscopic surgery in Sweden has been published (5). Apart from that study, there is no published information regarding HRQoL in Swedish patients with colon cancer.
Contradicting results have been presented regarding whether the presence of a stoma in surgically treated patients with colorectal cancer has a negative effect on HRQoL. Most of these studies have been performed on patients with rectal cancer (17). Notably, the participants in our study completed the questionnaire before they underwent surgery to create a stoma. This implies that it was the patients’ risk factors (as judged by the surgeon) or the advanced stage of their cancers that were related to the observed lower HRQoL in these patients. They might also have had poor expectations of life with a stoma, or it may have been that it was the information that they were to receive a stoma per se that contributed to their poor scores. Although this study included very few patients who were treated with a stoma alone, this group showed significantly worse functional scores and better symptom scores than patients treated with a stoma and bowel resection. Furthermore, a recent study of patients with colon cancer who answered questions postoperatively about what the most important factors for them in life were overall, related to the cancer disease, 78% reported that they considered not having a permanent stoma was the most important factor (76% stated that ‘being cured’ was most important factor) (18).
This study found that HRQoL was not affected by whether the patients underwent right-sided, left-sided or total colectomy (data not shown), and that patients with an advanced tumour stage (TNM IV) did not have significantly worse HRQoL than other patients. However, 10 of the 14 patients who were treated with a stoma without resection had metastatic disease (TNM IV), and these patients had very low functional scores and high symptom scores, indicating worse HRQoL at both baseline and at the 6-month follow-up.
Our study also found that younger patients had worse emotional and social functional QoL and more bowel problems (nausea/vomiting and diarrhoea) than older patients. This has also been observed by others and suggests that age-matched groups should be used to generate data for HRQoL comparisons (19).
In our study, comorbidity as assessed by ASA grade had a negative impact on global health status, physical function, fatigue, dyspnoea and constipation, both at baseline and at the 6-month follow-up. These data are also consistent with the results of other studies of colorectal cancer and other cancer types such as head and neck, lung and prostate cancer (20). In breast cancer, the effect of comorbidity explained most of the variance in nearly all subscales comparing demographic and clinical variables (21).
The data also showed that patients with a higher BMI had worse physical function and more nausea and vomiting, pain and financial difficulties. This observation has also been reported by others (22). There is increasing evidence that high body weight, often associated with a sedentary lifestyle, is related to impairments in QoL. Considering several different lifestyle factors, Schlesinger et al. (23) found that being non-obese had the strongest association with a high HRQoL, while another study reported decreased HRQoL in Dutch patients with high BMI (22).
The present study also showed that smokers had worse QoL than other patients at the 6-month follow-up compared with baseline. These data are consistent with the findings of studies of the general population (24) and of patients with colorectal cancer (25). Both these studies reported that current smokers had a higher likelihood of reporting poor physical health, poor mental health and activity limitations. It has also been reported that smoking rate was higher in young survivors of colon cancer and melanoma than in young individuals without cancer. These survivors also had higher age-adjusted smoking rates than survivors of other cancers (26).
The main strengths of this study were its prospective design and that it was population based. We also managed to recruit the patients before the start of treatment. The patient data were compared with those from a Swedish reference population (14). We also used one of the most widely used cancer-specific validated analysis instruments, the EORTC QLQ-C30, and because all patients agreed to be included in the local and national registries, we could also analyse data from non-included patients. In addition, we performed multiple regression analyses of medically important parameters, including lifestyle factors, such as BMI and smoking.
Analysis of data from the non-included patients showed that they had higher comorbidity, were less often treated surgically, had more advanced-stage tumours and had surgical treatment that more often included stoma creation. Thus, presumably, if these patients had been included, our results would have shown an even worse outcome for HRQoL because these non-included patients had evident risk factors for lower QoL (27). This could also be the case for the patients who were too ill to complete the questionnaire.
Other limitations were that this was a single-centre study, the reference data for the Swedish general population were collected several years before the present study started (15) and we did not analyse social and psychological factors known to influence HRQoL (28). A small study by Siassi et al. (29) showed that personality affects HRQoL more than clinical variables after a major surgery. We did not include data on the effect of chemotherapy, but other studies have shown that it is not a major factor affecting HRQoL (10). One could argue that had it been an important factor, there would have been an association between TNM stage and HRQoL.
In conclusion, this study showed that at baseline, many patients with colon cancer have low HRQoL compared with a refence population, but that HRQoL improved at the 6-month follow-up for patients with non-metastatic disease. We identified several risk groups: younger patients, patients with higher BMI, smokers and patients who underwent stoma surgery. These patients need enhanced support and identifying them would enable targeted early intervention and development of methods to facilitate rehabilitation, which could in turn enhance their HRQoL and improve their cancer prognosis.