Quality assurance in rectal cancer treatment.

Colorectal cancer is the cancer with the second highest cancer incidence in Europe. Roughly, 1 out of 3 patients with a colorectal malignancy has a rectal carcinoma. Surgery is the cornerstone in the curative treatment of rectal cancer. In the 1980s with conventional surgery, the 5-year local recurrence rate was over 20% and the 5-year overall survival rate around 50%. In the Swedish Rectal Cancer trial, in which 1,168 patients were included, preoperative radiotherapy in addition to conventional surgery resulted in a reduction of more than 50% in the 5-year local recurrence rate in comparison to conventional surgery alone (11 vs. 27%; p < 0.001). In addition, the 5-year overall survival rate improved from 48 to 58% if patients were treated with preoperative radiotherapy in addition to conventional surgery (p = 0.004). With total mesorectal excision (TME), by which the rectum with its mesorectum and visceral fascia are dissected sharply and under direct vision, local recurrence rates dropped and overall survival improved. In the Dutch TME trial, 5 × 5 Gy preoperative radiotherapy in combination with TME surgery was compared to TME surgery alone (1,861 patients). In this trial, the 5-year local recurrence rate for patients treated with TME surgery alone was similar to patients treated in the Swedish Rectal Cancer trial with blunt dissection in combination with preoperative 5 × 5 Gy radiotherapy (11%). If preoperative radiotherapy was added to TME surgery, the 5-year local recurrence rate was reduced to 5.6%. The overall survival rate at 5 years was 64% for both patients treated with TME surgery alone and patients treated with preoperative radiotherapy followed by TME surgery, compared to 48% for patients treated with blunt dissection alone in the previously mentioned Swedish trial. TME surgery is now considered the standard surgical procedure for rectal cancer. However, even if TME surgery is performed, surgical quality varies. First, these results indicate that improvements in the surgical procedure itself can result in major progress regarding long-term oncological outcome, such as decreased local recurrence rates and improved overall survival. Second, it illustrates that variation in surgical quality could lead to large differences in outcome. Recently, it was shown that surgical variation is not only important for patients with rectal cancer, but also plays an important role for the outcome of patients with colon cancer.