Het volume van chirurgische ingrepen en de impact ervan op ... - KCE

KCE Reports 113 Volume Outcome 59
5.2.7 Discussion
5.2.7.1 External validation of the definition of the procedure
According to the Belgian Cancer Registry, there were 1 140 new cases of oesophagus
and cardia cancer in Belgium in 2004 (see Table 5.1 (page 45). In the 2004 Minimal
Clinical Data (MCD), we identified 1 401 patients with the principal diagnosis of
malignant neoplasm of oesophagus or cardia.
Only 377 of these 1 401 patients (26.9%) underwent major oesophageal cancer surgery.
The MCD do not allow a distinction between surgery with palliative and curative intent.
This percentage is similar to the one found in other countries.
• In an English study, 30.9% of patients which were identified with a
malignant neoplasm of the oesophagus or cardia, underwent surgical
resection. 123
• Among all 4 904 Swedish residents who were diagnosed with oesophageal
cancer in the period 1987-2000, only 24.4% underwent oesophageal
cancer surgery with curative intent. This study only included resectable
oesophageal cancers which implies that oesophagectomies with palliative
intent were not counted. 127
5.2.7.2 Summarized results of literature review
The systematic literature search identified 8 systematic reviews in which the volume
1, 5, 59, 60, 62, 64, 69, 70
outcome association (VOA) for oesophageal cancer surgery was studied.
These systematic reviews were based on 22 primary studies. 93, 115, 116, 122, 123, 128-144 An
additional search for more recent studies which were published in the period 2004-
2009 resulted in 15 additional primary studies. 14, 15, 50, 70, 124, 127, 145-153 This brings us to a
total of 37 primary studies that analyzed the volume outcome association for
oesophageal cancer surgery. For more insight in how these studies were retrieved see
the Supplement.
On the basis of the systematic reviews it was concluded in Chapter 2 (see Table 2.2 on
page 19) that there is evidence for an inverse relation between hospital volume and
mortality for oesophageal cancer surgery.
This means that mortality decreases when the number of procedures performed by a
hospital increases. A similar relationship was found between surgeon volume and
mortality.
The highest-quality systematic review on oncologic procedures we identified in the
literature study is the one by Killeen and al.. 69 The interesting thing about this study is
that the authors estimated the number needed to treat, that is the number of patients
who must be treated to prevent one adverse outcome, from pooling available absolute
risk differences for each procedure. With respect to oesophageal cancer surgery,
Killeen and colleagues calculated that the number of oesphagectomies that a highvolume
provider needs to prevent one death is as low as seven to nine.
Two minimal hospital volume thresholds were retained from the literature search:
lower threshold of 6 oesophagectomies per annum and an upper threshold of 13
oesophagectomies per annum. These thresholds correspond more or less with the
thresholds in the systematic reviews. More importantly, they correspond with the
thresholds issued by the US Agency for Healthcare Research and Quality (i.e. 6 per
29, 126
annum) and the US Leapfrog Group (i.e. 13 per annum).
Detailed results of the literature review, using the data extraction template, are
described in the evidence tables in Appendix 8.