Primary treatment—does the surgeon matter?
The dominant factor contributing to the relatively poor
prognosis for colorectal cancer is the advanced stage of the
disease at the time of initial presentation: up to a third of
patients have locally advanced or metastatic disease, which
precludes surgical cure. Even in the patients who undergo
apparently curative resection, almost half die within five years.
In the west of Scotland, for example, about a third of 1842
patients presenting with colorectal cancer to seven hospitals
between 1991 and 1994 presented as emergencies. Potentially
curative resection was achieved in about 70% of patients
presenting electively; the curative resection rate was lower in
those presenting as emergencies. Five per cent of patients
admitted for elective surgery and 13% of those admitted as
emergencies died. Almost 60% of elective patients survived two
years, compared with 44% of patients admitted as emergencies.
These results are typical of population based studies in the
United Kingdom.
Variation among surgeons
Most surgeons acknowledge that the incidence of postoperative
complications varies widely among individual surgeons. It is
now almost 20 years since Fielding and his colleagues in the
large bowel cancer project drew attention to differences in
anastomotic leak and local recurrence rates after resection for
large bowel cancer.
In the original Glasgow Royal Infirmary study, which was
conducted in the 1980s, similar differences in postoperative
morbidity and mortality were noted. Furthermore, after
apparently curative resection, survival at 10 years varied
threefold among surgeons.
One might argue that these are historical data and therefore
bear little relevance to the current situation. In the current west
of Scotland study, however, although overall 33% of patients
presented as emergencies, the proportion varied among
hospitals from 24% to 41% and among surgeons from 10% to
50%.
Similarly, the proportion of patients undergoing curative
resection varied among surgeons from 45% to 82%;
postoperative mortality, in patients presenting electively, also
varied, from 0% to 17%. Several out of the 16 surgeons studied
performed less well than their colleagues.
Several factors apart from the individual surgeon’s skill
might influence these measurements of immediate and long
term outcome: case mix; surgical philosophy; assessment of
cure; quality of pathological reporting; other prognostic factors;
small numbers (see box). Despite these factors it seems likely
that the differences in the immediate postoperative morbidity
and mortality observed among surgeons in the above studies
are genuine. There have now been several analyses of
immediate outcome after colorectal cancer surgery, and in each
study, the results have been broadly comparable.
Effect of volume of surgery
Two explanations are possible for the differences in outcome
among surgeons—namely, the number of patients treated by
individual surgeons and whether these surgeons are specialists.
Although good evidence exists for other types of surgery
that volume of work is important, in colorectal cancer
convincing evidence that volume affects outcome is lacking. In
the Lothian and Borders study, 5 of 20 consultants were
responsible for 50% of the rectal cancer procedures. These five
surgeons had a significantly lower anastomotic leak rate, but this
may reflect specialisation rather than volume of work. In the
German multicentre study, a group of surgeons with low work
volume and performing only a few rectal cancer procedures
had local recurrence rates well within the range of results
obtained by individual surgeons with high work loads.
Furthermore, in a recent analysis of outcome in 927 patients
treated in the Manchester area, after correction for
non-prognostic variables no relation between volume and
outcome was noted.
Role of specialisation
The question of specialisation is more complex. Clearly rectal
cancer surgery represents a greater technical challenge than
colonic surgery. It therefore seems reasonable to expect—but it
is remarkably difficult to show (largely because of the small
numbers of patients treated by individual surgeons)—that
specialist surgeons achieve better outcome. Analysis of outcome
in almost 1400 patients with rectal cancer randomised in the
Swedish preoperative radiotherapy studies, suggested that local
recurrence and death rates were significantly lower in those
patients operated on by surgeons with more than 10 years’
experience as a specialist.
Perhaps the best information, however, comes from the
Canadian study in which 683 patients with rectal cancer were
treated by 52 different surgeons, five of whom were trained in
colorectal surgery. These five surgeons performed 109 (16%) of
the procedures. Independent of the type of training received by
the surgeons, 323 procedures (47%) were performed by
surgeons who each did fewer than 21 resections over the study
period. Multivariate analysis showed that the risk of local
recurrence was increased in patients treated both by surgeons
not trained in colorectal surgery and by surgeons performing
fewer than 21 resections. Similarly, disease specific survival was
lower in the patients treated by these two groups of surgeons.
These results suggest that both specialisation and volume may
be important independent factors determining outcome.
Surgeons are currently under intense scrutiny, partly
because readily available measures of outcome exist and partly
because outcome seems to differ substantially among surgeons.
The issues, however, are complex. Small numbers, annual
accounting, and failure to take into account case mix, surgical
intent, quality of staging, and prognostic factors may lead to
inappropriate conclusions.
Nevertheless, the results of the studies discussed here
suggest that some surgeons are less competent than their
colleagues and that these factors may compromise survival.
Considerable effort and resources are currently being poured
into large multicentre studies of adjuvant chemotherapy and
radiotherapy in an effort to provide a marginal improvement in
the survival of patients with colorectal cancer. If, by
specialisation, the overall results of surgery could be
improved—and evidence suggests that this is so—the impact on
survival might be greater than that of any of the adjuvant
therapies currently under study.
