Comparing oncological outcomes of laparoscopic versus open surgery for colon cancer: Analysis of a large prospective clinical database.

BACKGROUND: Oncological outcomes of laparoscopic colon cancer surgery have been shown to be equivalent to those of open surgery, but only in the setting of randomized controlled trials on highly selected patients. The aim of this study is to investigate whether this finding is generalizable to real world practice. METHODS: Analysis of prospectively collected data from the BioGrid Australia database was undertaken. Overall and cancer specific survival rates were compared with cox regression analysis controlling for the confounders of age, sex, BMI, ASA score, hospital site, year surgery performed, procedure, tumor stage, and adjuvant chemotherapy. RESULTS: Between 2003 and 2009, 1,106 patients underwent elective colon cancer resection. There were differences between the laparoscopic and open cohorts in BMI, procedure, post-operative complication rate, and tumor stage. When baseline confounders were accounted for using cox regression analysis, there was no difference in 5 year overall survival (χ(2) test 1.302, P = 0.254), or cancer specific survival (χ(2) test 0.028, P = 0.866). CONCLUSION: This large prospective clinical study validates previous trial results, and confirms that there is no difference in oncological outcome between laparoscopic and open surgery for colon cancer.

Impact of anastomotic leak on recurrence and survival after colorectal cancer surgery: a BioGrid Australia analysis.

BACKGROUND: There is conflicting evidence regarding the oncological impact of anastomotic leak following colorectal cancer surgery. This study aims to test the hypothesis that anastomotic leak is independently associated with local recurrence and overall and cancer-specific survival. METHODS: Analysis of prospectively collected data from multiple centres in Victoria between 1988 and 2015 including all patients who underwent colon or rectal resection for cancer with anastomosis was presented. Overall and cancer-specific survival rates and rates of local recurrence were compared using Cox regression analysis. RESULTS: A total of 4892 patients were included, of which 2856 had completed 5-year follow-up. The overall anastomotic leak rate was 4.0%. Cox regression analysis accounting for differences in age, sex, body mass index, American Society of Anesthesiologists score and tumour stage demonstrated that anastomotic leak was associated with significantly worse 5-year overall survival (χ 2 = 6.459, P = 0.011) for colon cancer, but only if early deaths were included. There was no difference in 5-year colon cancer-specific survival (χ 2 = 0.582, P = 0.446) or local recurrence (χ 2 = 0.735, P = 0.391). For rectal cancer, there was no difference in 5-year overall survival (χ 2 = 0.266, P = 0.606), cancer-specific survival (χ 2 = 0.008, P = 0.928) or local recurrence (χ 2 = 2.192, P = 0.139). CONCLUSION: Anastomotic leak may reduce 5-year overall survival in colon cancer patients but does not appear to influence the 5-year overall survival in rectal cancer patients. There was no effect on local recurrence or cancer-specific survival.

Extent of mesorectal invasion is a prognostic indicator in T3 rectal carcinoma.

BACKGROUND: The aim of this study was to determine if local recurrence (LR) rates in patients with minimally invasive and advanced T3 rectal cancer are different. This may influence the use of adjuvant therapy. METHODS: Consecutive patients with T3 rectal cancer undergoing curative surgery were classified into minimally invasive or advanced groups. Minimally invasive T3 was defined as a tumour that had invaded beyond the muscularis propria on microscopic examination only, whereas advanced T3 tumours had invasion beyond the muscularis propria that was obvious on macroscopic examination and confirmed histologically. Local recurrence rates of the two groups were compared by construction of Kaplan-Meier curves. The log-rank test was used to determine equivalence, and Cox regression to estimate the hazard ratio. The Grambsch- Therneau test and graphical comparison of predicted and observed Kaplan-Meier curves was used to test the proportional hazards assumption. RESULTS: There were 222 patients in total, 74 in the minimally invasive group and 148 in the advanced. The overall LR rate was 11.2%. The LR rates in the minimally invasive and advanced groups were 5.4% and 14.2%, respectively. The log-rank test gives a P value of 0.042 for equivalence, with the minimally invasive patients doing significantly better. The hazard ratio estimated by Cox regression was 0.35 (early relative to advanced), 95% confidence intervals (0.12, 1.0). There was no evidence of confounding by age at surgery, pathology type, gender or postoperative adjuvant therapy. CONCLUSIONS: The extent of invasion into the mesorectum appears to be an independent prognostic variable. If oncologically sound surgical techniques are employed, the LR rate of patients with minimal invasion is low. Adjuvant therapy may not confer additional benefit in this group.

Initial impact of Australia's National Bowel Cancer Screening Program.

OBJECTIVE: To examine the initial impact of the National Bowel Cancer Screening Program (NBCSP), which was launched in May 2006 and offers faecal occult blood testing to Australians aged 55 or 65 years. DESIGN AND SETTING: Review of data on colorectal cancer (CRC) cases diagnosed between May 2006 and June 2008 from a prospective database used at 19 Australian hospitals, linked and analysed by BioGrid Australia. MAIN OUTCOME MEASURES: Number of CRC cases detected through the NBCSP or symptomatic presentation, and differences by sex, stage at diagnosis, tumour location and level of socioeconomic disadvantage. RESULTS: 1628 cases of CRC were identified; 1268 had information on the patients' test status as part of the NBCSP, and 40 of these (3.2%) were recorded as being detected by the NBCSP. Of 75 CRC cases in patients aged 55 or 65 at diagnosis, 22 were NBCSP-detected. Overall, there was no difference in NBCSP-detected cases by sex. The distribution of tumour locations was similar between NBCSP-detected cases and symptomatic cases, but NBCSP-detected cancers were diagnosed at an earlier stage than symptomatic cancers (stage I, 40% v 14%; stage IV, 3% v 15%, respectively). Of patients diagnosed through the NBCSP, 63% were from areas of least socioeconomic disadvantage (deciles 8-10) and 18% were from the most disadvantaged areas (deciles 1-4) (P=0.0375). CONCLUSION: Initiation of the Australian NBCSP has had a measurable impact on CRC stage at diagnosis, and an improvement in survival would be anticipated. The lower uptake among people from disadvantaged areas is of concern.