IT is well known that in all forms of cancer treated by radical surgery the patient's prognosis depends very much on the extent of local and lymphatic spread and on the likelihood of venous dissemination. To proceed further than this and to attempt to define the relative importance of each of these three methods of spread is only possible when a large series of carefully documented cases has been kept under observation for several years by a really efficient follow-up. This information is now available with regard to cases of rectal cancer treated by radical surgery at St. Mark's Hospital and the purpose of this paper is to record the degree to which the prognosis is influenced by the extent of local, lymphatic and venous spread.St. Mark's Hospital is a special hospital for diseases of the colon and rectum, and since 1924 a research into the pathology and treatment of rectal cancer has been continued in the pathology department with the help of a grant from the British Empire Cancer Campaign. Some preliminary reports have already been published but the present analysis is the first comprehensive summary of this long-term research project and covers the 25 years 1928-52.During these 25 years a total of 3596 rectal cancer patients were admitted to hospital or seen in the Out-patient Department. Of these, 2447 were treated by a surgical operation which removed the primary tumour. Every possible endeavour has been made to keep in touch with operation survivors, and only 28 have not been traced. These have been assumed to be dead, but since they constitute only 1 1 per cent of all cases they exert no appreciable effect on the statistics.The crude 5-year survival rate of all patients treated by surgical removal of the primary tumour was 48x3 per cent. It might be assumed that this figure would provide a basic standard by which to measure the effect of various forms of spread subsequently to be considered, but crude survival rates are not altogether satisfactory for such a purpose because of variation in the age and sex composition of the groups of patients to be compared. When comparing groups of patients of dissimilar age and sex, it is more accurate to use " age and sex corrected " 5-year survival rates. This point will be appreciated when we recall that the crude 5-year survival rate simply records the percentage of individuals still living after 5 years and makes no distinction between deaths which have been due to cancer and deaths due to intercurrent diseases, the incidence of which is a function of both age and sex.There is more than one statistical device for producing a corrected survival rate and the one adopted here was recommended by Dr. Percy Stocks and has already been described (Dukes, 1957). The effect of this correction on our figures

Anyone who walks down Fulham Road through the district SW3 passes first the Royal Marsden Hospital (formerly the Cancer Hospital), then the Brompton Hospital and next to this a new white building labelled 'Chester Beatty Research Institute of the Institute of Cancer Research', continuous with which is a red brick building with the inscription in letters of gold across its face 'Royal Cancer Hospital (Free): Chester Beatty Research Institute'. This well-known Cancer Research Institute, when first founded in 1909, was in the grounds of what is now the Royal Marsden Hospital but thirty years later it was moved to the building in Fulham Road, previously the Freemasons' Hospital, and earlier still the Chelsea Hospital for Women. This move to larger quarters, which took place in 1939, was made possible by the generous benefaction of Sir Alfred Chester Beatty whose name is now incorporated in the title. The adjacent white building is a further extension opened in 1961. The 'Institute of Cancer Research of the Royal Cancer Hospital' includes not only the Chester Beatty Research Institute but also the departments of Physics, Radiotherapy and Clinical Research of the Marsden Hospital. The Director of each of these is responsible to the Committee of Management of the Institute for research activities and to the Board of Governors of the Hospital for hlinical work.