CLINICS 2011;66(6):1035-1040 limits with absolute values that typically do not exceed 10 points, and at most are as high as 13.1 points. McHorney and Tarlov34 estimated that a 13-point change in an SF-36 score would be necessary to generate a clinically significant change. Using a 13-point criterion, one would conclude, based on our confidence interval results, that the SF-36 outcomes in the APR and LAR groups are practically equivalent. Our study suffers from the limitations of a retrospective review. In order to more accurately assess changes in QOL after surgery, only those patients who had completed the preoperative QOL questionnaire were included. Therefore, one could argue that our study cohort may not be representative of the experience of all patients who under- went surgery within our department during the study period. In order to minimize this potential limitation, we compared the demographics, tumor and treatment char- acteristics, and oncologic outcomes of the patients included in the study with those who were excluded. No statistically significant difference could be found between the two groups, suggesting that the study group likely had characteristics similar to the entire population. In the face of several statistically nonsignificant results as they relate to QOL comparison, one could argue whether our study has sufficient evidence to suggest that the outcomes for the APR and LAR groups are similar. The confidence intervals for mean differences between the groups presented in Tables 4 and 5 have absolute values that, with few exceptions, do not exceed 10 points and have an upper limit of 13.1 points. McHorney and Tarlov34 estimated that a 13-point change in an SF-36 score would be necessary to generate a clinically significant change. Therefore, using a 13-point criterion, one would conclude that, based upon our confidence interval results, the SF-36 outcomes in the APR and LAR groups are essentially equivalent. Although all patients had a baseline QOL assessment, this assessment did not take place for every patient at all of the follow-up periods. As a result, different samples were formed in each period. Also, we could not evaluate other factors affecting QOL, such as urinary and sexual function. Moreover, excluding patients without baseline QOL assess- ment might have created a unique sample that could not retract the reality. Because QOL is likely associated with multiple other factors35 these results may be confounded by such factors. In order to circumvent this possibility, we adjusted our analysis for the following factors that might influence QOL: age at surgery,36 BMI,37 pathologic stage,26 use of radiation therapy,38 and 30 d postoperative complica- tions.39 The results of this study that evaluated preoperative and follow-up SF-36 over a prolonged postoperative period for a large cohort of patients are likely a reflection of general QOL of patients undergoing the two operations. Irrespective of the reasons for the results, the finding that patients undergoing APR for low rectal cancer have long-term QOL similar to those undergoing restorative resection is likely to have implications for practice. The decision as to the correct surgical approach, that is, LAR or APR, is sometimes extremely difficult for some patients with rectal cancer close to but not involving the sphincter. In these circumstances, there may understandably be a significant amount of emotional pressure on both the patient and the clinician to favor a restorative resection over a permanent 1039 Quality of life after rectal cancer surgery de Campos-Lobato LF et al. stoma. The findings of this study, which showed that patients with low rectal cancer after APR have an equivalent general QOL to LAR patients over the long term, may help preoperatively counsel patients for whom the decision to perform APR has been made. Further, the findings may also foster more rational treatment decisions that are guided predominantly by expectations of oncologic outcomes both pre-and intraoperatively by clinicians, when they are faced with ambivalence as to the preferential approach for patients with ultra-low-lying rectal cancer. CONCLUSION Patients undergoing APR for low rectal cancer have similar long-term overall QOL as those undergoing restora- tive resection. These findings will help counsel patients with low rectal cancers, who are being considered for APR. REFERENCES 1. Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer statistics, 2009. CA Cancer J Clin. 2009;59:225-49, doi: 10.3322/caac.20006. 2. Heald RJ, Ryall RD. Recurrence and survival after total mesorectal excision for rectal cancer. Lancet. 1986;1:1479-82, doi: 10.1016/S0140- 6736(86)91510-2. 3. Carlsen E, Schlichting E, Guldvog I, Johnson E, Heald RJ. Effect of the introduction of total mesorectal excision for the treatment of rectal cancer. Br J Surg. 1998;85:526-9. 4. Wibe A, Moller B, Norstein J, Carlsen E, Wiig JN, Heald RJ, et al. A national strategic change in treatment policy for rectal cancer-- implementation of total mesorectal excision as routine treatment in Norway. A national audit. Dis Colon Rectum. 2002;45:857-66, doi: 10. 1007/s10350-004-6317-7. 5. Sauer R, Becker H, Hohenberger W, Rodel C, Wittekind C, Fietkau R, et al. Preoperative versus postoperative chemoradiotherapy for rectal cancer. N Engl J Med. 2004;351:1731-40. 6. Janjan NA, Abbruzzese J, Pazdur R, Khoo VS, Cleary K, Dubrow R, et al. Prognostic implications of response to preoperative infusional chemor- adiation in locally advanced rectal cancer. Radiother Oncol. 1999;51:153- 60, doi: 10.1016/S0167-8140(99)00054-7. 7. Gravalos C, Garcia-Escobar I, Garcia-Alfonso P, Cassinello J, Malon D, Carrato A. Adjuvant chemotherapy for stages II, III and IV of colon cancer. Clin Transl Oncol. 2009;11:526-33, doi: 10.1007/s12094-009-0397- 8. 8. Giantonio BJ, Catalano PJ, Meropol NJ, O’Dwyer PJ, Mitchell EP, Alberts SR, et al. Bevacizumab in combination with oxaliplatin, fluorouracil, and leucovorin (FOLFOX4) for previously treated metastatic colorectal cancer: results from the Eastern Cooperative Oncology Group Study E3200. J Clin Oncol. 2007;25:1539-44, doi: 10.1200/JCO.2006.09.6305. 9. O’Neil BH, Tepper JE. Current options for the management of rectal cancer. Curr Treat Options Oncol. 2007;8:331-8, doi: 10.1007/s11864-007- 0048-7. 10. Perry WB, Connaughton JC. Abdominoperineal resection: how is it done and what are the results? Clin Colon Rectal Surg. 2007;20:213-20, doi: 10. 1055/s-2007-984865. 11. Wu JS, Fazio VW. Management of rectal cancer. J Gastrointest Surg. 2004;8:139-49, doi: 10.1016/j.gassur.2003.10.011. 12. Chessin DB, Guillem JG. Abdominoperineal resection for rectal cancer: historic perspective and current issues. Surg Oncol Clin N Am. 2005;14:569-86, vii., doi: 10.1016/j.soc.2005.04.002 13. Wibe A, Syse A, Andersen E, Tretli S, Myrvold HE, Soreide O, et al. Oncological outcomes after total mesorectal excision for cure for cancer of the lower rectum: anterior vs. abdominoperineal resection. Dis Colon Rectum. 2004;47:48-58, doi: 10.1007/s10350-003-0012-y. 14. Yau T, Watkins D, Cunningham D, Barbachano Y, Chau I, Chong G. Longitudinal assessment of quality of life in rectal cancer patients with or without stomas following primary resection. Dis Colon Rectum. 2009;52:669-77, doi: 10.1007/DCR.0b013e31819eb970. 15. Tsunoda A, Tsunoda Y, Narita K, Watanabe M, Nakao K, Kusano M. Quality of life after low anterior resection and temporary loop ileostomy. Dis Colon Rectum. 2008;51:218-22, doi: 10.1007/s10350-007-9101-7. 16. O’Leary DP, Fide CJ, Foy C, Lucarotti ME. Quality of life after low anterior resection with total mesorectal excision and temporary loop ileostomy for rectal carcinoma. Br J Surg. 2001;88:1216-20. 17. RAND Corporation. Medical Outcomes Study: 36-Item Short Form Instrument Survey. 2010; Available at: http://www.rand.org/health/ surveys_tools/mos/mos_core_36item.html. Accessed 2/26/2011, 2011. 18. Cornish JA, Tilney HS, Heriot AG, Lavery IC, Fazio VW, Tekkis PP. A meta-analysis of quality of life for abdominoperineal excision of rectum