Data dreaming over four decades

While working day to day in the surgical treatment of colorectal cancer, it can be a struggle to see improvements in overall outcomes. Complications are concerning, tumour recurrences devastating. The two papers by Dent et al. in this issue allow us to lift our horizon to view the trends and outcomes of colorectal cancer treatment over a 43-year period from 1971 to 2013. This time span saw radical changes in the treatment of colorectal cancer: the beginning of screening programmes for colorectal cancer, the introduction of adjuvant chemotherapy for nodepositive cancer, the addition of preand post-operative chemoradiotherapy in the treatment of rectal cancer, the widespread adoption of the surgical principle of total mesorectal excision and the development of laparoscopic-assisted resection of colon and rectal cancer. The remarkable aspect of the prospective database of 5217 consecutive patients described in these papers by the Concord colorectal surgical group is its completeness. Having worked in the unit in the early 1990s, I can attest to the rigour with which the authors chased down missing data points. While over 90 peer-reviewed articles have been published from this database, some broad themes emerge from these two articles. The most important and welcome is the 5-year cancer-specific survival rate increasing from an annual average of 46% during 1971–1974 to 78% during 2005–2008. This seems to be due to a significant survival improvement in Stage B and C patients which is matched with a backward stage migration flow with Stage D patients dropping from 28% to 17% and Stage A increasing from 11% to 21%. Presumably, the Stage D patients migrate to Stage C and the Stage C patients to Stage B etc. This proposition is further supported by a decrease in mean tumour size, percentage of highgrade tumours, rate of venous invasion in tumours, lymph node involvement, the percentage increase in polypoidal tumours and tumours with contiguous adenoma. It would seem unlikely that tumour biology has changed in that time period. Rather we are seeing the result of numerous community awareness programmes and screening programmes increasing the fecal occult blood test-positive colorectal cancer diagnosis and decreasing the time between the recognition of the first symptom and appropriate referral. The National Bowel Screening Program has been progressively rolled out after a pilot study in 2003 and has been shown to cause a migration to earlier tumour stage at diagnosis in the screening programme participants. Less likely but possible is a change in socio-economic status of the draining referral region. There was a sharp rise in the percentage of operations restoring rectal continuity over the first 5 years of the database to 70%, after which the figure remained static. The rate of abdominoperineal resection was 23.4% in Victoria in 2005. The ALaCart trial had a figure of 92.5% of restorative resections but this figure may be skewed by selection bias of both surgeons and patients into the trial. With the emergence of transanal total mesenteric excision technique, the use of the surgical robot in the treatment of rectal cancer and the adoption of the watch and wait principle following preoperative radiotherapy for colorectal cancer, it is hoped to see that the restorative resection rate will continue to rise. The decrease in anastomotic leak rate from 12% in the early 1970s to 2% in the last years of the database, the decline in early reoperation rate and the decline in the 30-day mortality are a tribute to an organization where the patient outcome was always the most important consideration. While improvements in preand post-operative care and the evolution of intensive care contributed to these outcomes, the surgery itself was an important factor. The use of standardized surgical techniques where the recognition and dissection of surgical planes are paramount and the fact that operations were consultant-led are undoubtedly important factors. It is salutary to note that the rate of medical complications failed to decrease during this period. One development that could change this disturbing statistic is the rise in the number of preoperative physicians in high-risk clinics who can identify potential medical issues such that they may be remedied preoperatively or indeed if the risks are of such magnitude the patient can be counselled as to the adverse risk-benefit ratio of the procedure. Looking ahead at the next 40 years and the inevitable innovations that will arrive to influence how we treat colorectal cancer mechanisms, we will need to compare these future outcomes with those of the past not just by national or international databases, but by local data collection that captures the influences of the changes on the actual population we treat. By doing this, with annual analysis, quality control can be ensured and the most effective way to spend the health dollar in the management of colorectal cancer can be determined.