Multidisciplinary Symposium — Colorectal Cancer

Cancer medicine is slowly embracing the uncomfortable reality that adjuvant modalities are often best administered before operative surgery rather than after. Cedermark points out that there are 20 published series which show a clear survival advantage for pre-operative radiotherapy in rectal cancer and only one showing such advantage for post-operative radiotherapy. Similarly direct comparison of preand post-operative short course radiotherapy in the Swedish Rectal cancer trial showed a clear advantage for the pre-operative option. Pahlman and Glimelius state that ‘surgery fails at the margins, radiotherapy in the centre’ (of solid tumours). One of the principal risks of surgical failure is an exposed circumferential margin (CMI): what therefore could be more logical than to minimize by pre-operative radiotherapy the risk that such exposure will prove lethal? Cells spilled from an irrradiated cancer must be intrinsically less likely to be viable and thus able to implant whilst an operation field widely contaminated with viable cells is unlikely to be treated cytostatically by post-operative radiotherapy. Furthermore the modern J Colon Pouch with an ultralow anastromosis is far better unirradiated in terms of lavatory function. Similar advantages may also apply to the use of pre-operative chemotherapy as benefit is known to be greatest with small deposits of malignant cells — probably micrometastases, circulating cells and perhaps cells spilled during surgery. Surely therefore the future will bring a pressing need to decide who needs radiotherapy and who needs chemotherapy at an initial assessment which culminates in a treatment plan where the final and hopefully victorious surgical assault is upon a suitably subdued enemy? The age of imaging is dawning!