Scope of the Problem
There are numerous predictive risk factors for local recurrence of colorectal cancer (CRC) following surgery for curative intent. Among them are tumor stage, grade of cancer, depth of tumor penetration, obstruction, perforation, lymphovascular invasion and anastomotic leak (AL). Albeit infrequent, AL has an impact on post-operative morbidity and mortality yet its impact oncologic outcomes are uncertain.
The role of AL in oncologic outcome is conflicting in the literature. Mirnezami and colleagues1 conducted a meta-analytical review investigating outcomes in CRC patients who experienced AL in terms of local recurrence, distant recurrence and survival. A total of 21 studies, 14 prospective and 7 retrospective, with a combined study population of 21,902 patients met inclusion criteria.
- Data from 13 studies showed a significant effect of AL on local recurrence after rectal anastamoses with a pooled odds ratio of 2.05 (95% CI = 1.51-2.8; P = 0.0001)
- Only 3 of 13 studies evaluated data on colonic anastamosis only. The results showed a greater number yet statistically insignificant trend of local recurrences after AL
- Meta-analysis of 7 studies assessing the impact of AL on distant recurrence showed a greater yet not statistically significant number of distant recurrences after AL with odds ratio of 1.38 (95% CI = 0.96-1.99; P = 0.083)
- Fourteen studies reported on long term survival, with meta-analysis revealing a significantly reduced cancer-specific survival following AL with an odds ratio of 1.64 (95% CI = 1.4-1.91; P = 0.0001)The authors concluded that the results of this analysis support AL as having a negative prognostic impact on local recurrence of rectal cancer. Due to the lack of studies evaluating colonic AL alone, it is difficult to ascertain clarity on impact however; there was an insignificant tendency toward increased local recurrence. The authors believe this study provides convincing evidence that supports AL as a contributor to adverse oncologic outcomes.1
In this era of high science and personalized medicine, considering all risk factors for poor outcomes is critical. This exploration commences at the time of diagnosis with performing a thorough medical, surgical, psychosocial and family history to ascertain the inherent patient-related risk factors. Typically, when one thinks of personalized medicine we think of the shift from cell-cycle specific chemotherapy to targeted agents directed at the unique molecular features of cancer cells, and immunotherapeutics that modulate the tumor immune response.2 However, personalizing therapy goes beyond the pharmaco-biologic approach. This is evidenced by the work of Mirnezami et al.1, analyzing the risk of negative outcomes for CRC patients who experience post-operative AL. Their conclusions rightfully suggest the vital role of a technically expert surgeon to minimize AL as well as implications for further patient risk stratification and guidance for follow-up in order to minimize undesired outcomes. Additionally, they support the advent for technological advancements in contributing positively to oncologic surgical outcomes in CRC patients.
- Mirnezami A, Mirnezami R, Chandrakumaran K, et al. Increased local recurrence and reduced survival from colorectal cancer following anastomotic leak. Ann Surg. 2011; 253:890-899. doi: 10.1097/SLA.0b013e3182128929 Link to abstract: http://journals.lww.com/annalsofsurgery/Abstract/2011/05000/Increased_Local_Recurrence_and_Reduced_Survival.9.aspx
- Schilsky RL. Personalized medicine in oncology: the future is now. Nat Rev Drug Discov. 2010; 9:363-366. doi:10.1038/nrd3181 Link to abstract: http://www.nature.com/nrd/journal/v9/n5/abs/nrd3181.html