The ‘good’, the ‘bad’, and the ‘ugly’ rectal cancers

Some decades ago, patients with a newly diagnosed rectal cancer were locally staged clinically, using the finger and a rectoscope. If the tumour was judged resectable, patients were operated upon whereas those judged not possible to resect were referred for preoperative radiotherapy. Delayed surgery was then performed if the tumour had diminished in size or was no longer clinically fixated by rectal palpation. In those days, 30 40% of the rectal cancers recurred locally even if surgery was successful. This often resulted in severe suffering prior to death. Five-year survival was less than 40% [1 3]. Since then, most aspects of the care of rectal cancer patients have improved. The introduction of more precise surgery, total mesorectal excision (TME), and the use of preor postoperative radiotherapy or radiochemotherapy have contributed both to much lower local recurrence rates and improved survival. Presently, population-based studies can report local recurrence rates less than 10% and 5-years survival of 60% [4 7]. Radiotherapy, alone or with chemotherapy is given not only to the 10 15% non-resectable cancers but also to many less advanced tumours since it lowers local recurrence rates and improves survival [8,9]. Such comparably low levels of local recurrence rates can not be achieved if preoperative radiotherapy is only given to the most advanced T4 tumours [10]. The availability of different treatment options, each having pros and cons (particularly concerning late adverse effects [11]), has resulted in an increasing demand on better preoperative staging. Through the years, the possibilities to stage rectal cancer have also improved, although not introduced into clinical routine as rapidly as other aspects of care. Clinical staging, by evaluating fixation to the surrounding tissues is still used to identify locally advanced pelvic disease and to select patients for different preoperative treatments. The limitation of the clinical examination is obvious. In the case of large pelvic masses the mass effect of the tumour may cause fixation without corresponding tumour infiltration. There is also an obvious limitation of the clinical examination regarding estimation of tumour extent to different anatomical structures, some of them not reachable by the examining finger. The different imaging techniques, used during the past decades to locally stage rectal cancer [12], have to a various extent adopted pathological staging systems and used histopathology as a standard of reference to estimate sensitivity and specificity. In transrectal ultrasonography this had resulted in a uTstaging system, corresponding to the pathological pT-staging system. The sensitivity, specificity and limitations of different imaging techniques to stage early rectal cancer with pathology as a standard of reference is extensively documented, however, mostly in single-centre studies [12]. In contrast, these parameters are not as well known for the locally advanced rectal cancers, since many of the surgical and pathological examinations of these tumours are performed after preoperative treatment with an effect on tumour stage [13 15]. More recently, the circumferential resection margin (crm), the mesorectal fascia and the remaining