Treatment of early colorectal cancers: too many choices?

Two papers in this issue of Endoscopy bring us a head-to-head comparison of minimally invasive treatments of early colon and rectal cancers, offering a perfect opportunity to consider where we are going with the surgical treatment of the increasingly common finding of early colon cancer.

Kiriyama and co-authors, representing the world’s pre-eminent institution for endoscopic submucosal dissection (ESD), present a retrospective review of 297 colorectal ESD procedures, comparing them with their cancer resections by means of laparoscopically assisted colorectal surgery (LAC) over a similar 10-year timeframe [1]. The colectomies were only those for T1 cancers, making the two groups at least somewhat comparable, though there were important differences: for example there were more rectal lesions in the ESD group and obviously more advanced cancers in the LAC group. The results of the comparison are in general what one would intuitively expect – more complications, particularly wound infections, in the LAC group, longer length of hospital stay in that group, etc. There were some surprises however that deserve comment. The mean operative time for ESD was significantly shorter than the laparoscopic surgery time (106 min vs. 206 min), in spite of a mean tumor size of 3.7 cm in the ESD group. This probably says more about the large volume and experience with ESD of the Tokyo group than it does about inherent benefit of the two procedures. I would hazard a guess that in the majority of cancer centers outside of Japan the operative times would be exactly reversed, with ESD taking 120 to 180 min and the laparoscopic procedure taking 90 to 150 min. A particular difference was seen for rectal cancers where operative times were even shorter for the ESD (129 min) compared with rectal resections (more than 4 hours).

The authors conclude that their study shows high efficacy, cost – effectiveness, and safety of colorectal ESD when compared with laparoscopic colectomy. I suppose that this is a valid conclusion based on the numbers presented; however, in all fairness, the fact that almost all of their colectomy patients had invasive cancers and therefore were not candidates for ESD – that is, to achieve a cure a more extensive, time-consuming, and dangerous procedure was inescapable – makes the argument somewhat deceptive. A better way to read this paper is that, at a center like the Tokyo National Cancer Center, as colorectal cancers become more invasive the morbidity and cost of their treatment steadily increases.

In this issue there is also a similar paper from Korea [2]. In their study, Drs Park, Min and their surgical colleagues address only early rectal lesions, comparing ESD with another minimally invasive surgical treatment, transanal endoscopic microsurgery (TEM), which typically provides a full-thickness local resection. In this paper, albeit with lower numbers, ESD also comes out looking good: quicker, less painful, and equally effective from an oncologic standpoint. Unlike the first paper, there is a striking similarity between the two groups in the lesions treated. Minimally invasive colorectal surgeons pride themselves on offering TEM rather than open or laparoscopic rectal resection as it is many times less invasive and less morbid – now they have been “one-upped.” To be fair though, the TEM procedure took longer because it is a full-thickness repair which requires closure. TEM is also not infrequently performed as a partial thickness resection – a surgical submucosal excision – in which case it is much faster than ESD. It is still however, more expensive and less available. Surgeons elect to perform TEM full-thickness resection because they want to determine the full-thickness histopathology, and often in order to sample the perirectal lymph nodes, and in certain cases as a curative resection for T1 and even T2 cancers.

I think that two major messages can be taken from these two papers. The first is that it is a shame that the vast majority of patients worldwide who have early cancers of the colon and rectum, confined to the mucosa, are subjected to laparoscopic or open colon resections. This is wasteful of healthcare financial resources and really is not optimal care for the patient. There should be an international drive to get surgeons and gastroenterologists up to speed on ESD, so that all patients have access to the “best” treatment for these tumors. The second point that these articles highlighted to me is that it is time to change how we address gastrointestinal cancers, particularly colorectal cancers. Read superficially, the papers can sound like the traditional “surgery versus endoscopy” way of treating disease – meaning that if the surgeon gets to the patient first the patient will receive a major surgical resection, but if the gastrointestinal endoscopist sees them an endoscopic resection might happen. This is obviously not optimal care. There are many options for care of the colorectal cancer patient: ESD, TEM, laparoscopic colectomy, laparoscopically assisted endoluminal resection, and open radical resections, each with very specific patient indications. And this trend for innovative treatment will only increase: clinical experience with natural orifice transluminal endoscopic surgery (NOTES) colectomy is increasing [3], and full-thickness endoscopic resection is being investigated [4]; perhaps with the addition of sentinel node biopsy [5], this will broaden the application of organ-sparing surgery to an even greater number of early cancer patients. In the future, optimal care of the colorectal cancer patient will be take place in a center that offers expertise in all of these approaches, where patients will be assessed by a multidisciplinary team and assigned to the least invasive treatment modality, to ensure cost-effective, patient-friendly curative cancer care.

• References

• 1 Kiriyama S, Saito Y, Yamamoto S et al. Comparison of endoscopic submucosal dissection with laparoscopic-assisted colorectal surgery for early colorectal cancers: a retrospective analysis. Endoscopy 2012; 44: 1024-1030
• 2 Park SU, Min YW, Shin JU et al. Endoscopic submucosal dissection and transanal endoscopic microsurgery for nonpolypoid rectal carcinoma in situ and submucosa-invading cancer. Endoscopy 2012; 44: 1031-1036
• 3 Telem DA, Berger DL, Bordeianou LG et al. Update on transanal NOTES for rectal cancer: transitioning to human trials. Minim Invasive Surg 2012; 287613. Epub 2012 May 20
• 4 Rieder E, Martinec DV, Dunst CM et al. A novel technique for natural orifice endoscopic full-thickness colon wall resection: an experimental pilot study. J Am Coll Surg 2011; 213: 422-429
• 5 Asakuma M, Cahill RA, Lee SW et al. NOTES: the question for minimal resection and sentinel node in early gastric cancer. World J Gastrointest Surg 2010; 2: 203-206