More Emphasis on Resection Rates!

Abstract

Overall lung cancer survival rates are mainly driven by the proportion of patients undergoing curative surgery. The resection rate usually includes all patients operated upon and is thus strongly related to survival. However, although resection rate is increasingly more emphasized as a quality indicator, it is not an indicator of appropriate selection of patients to lifesaving treatment. The term resection rate is not even properly defined, and there is no standard for how it should be reported. Therefore, one should be cautious in comparing resection rates that may differ by several percentage points depending on their context. For example, whether small-cell lung cancer (SCLC) and other less frequent histological subgroups are excluded, whether cases based on death certificate only (DCO) are included, whether only curative resections are counted, and whether histologically unconfirmed cases are a part of the denominator. A definition should also account for what should be regarded as a resection in terms of completeness of tumor removal. Should synchronous tumors be counted separately or together? Further, overestimation might occur if the completeness of the cancer registration in the population under investigation is poor. The series from Iceland reported in this issue of Journal of Thoracic Oncology highlights the resection rate, which is relatively high, at 26.4% for a whole nation. 1 One should, however, be aware that 306 cases without histological diagnosis were excluded, along with SCLC, carcinoids, sarcomas, and carcinoma in situ. If those without tissue diagnosis were included, the resection rate would be 22.0%, which is still an optimistic number. The authors should be praised for putting resection rates on the agenda of research. Several studies have previously reported national resection rates, but there has been too little attention, research, and knowledge devoted to this very important indicator. In England, the median national rate was 9% between 2004 and 2006, excluding from the denominator SCLC cases and cases reported from DCOs. 2 Denmark’s latest results were 16.0% for 2007, probably including SCLC but without information on which selection criteria were used. 3 For older reports on national resection rates, Wilkin et al. 4 have summarized a dozen European countries in a benchmark report from 2008. In Norway, we recently found a rate of 19.1% including SCLC and 22.5% excluding SCLC, while excluding DCOs for both. 5 What the optimal resection rate for lung cancer is has never before been properly investigated. We also lack evidence based research to support recommendations for what range one should aim for. Laroche 6 has been quoted to set the standard for limits in the United Kingdom at 20%. In Denmark, 25% is the goal. 3 When Torsteinsson et al. report their national results with high quality (complete) data and good survival of patients, they contribute to empirical knowledge of what resection rates should be at a national level. They can present a reliable denominator because registration of cancer cases is considered complete in Iceland with the country’s high quality national registry. Why is a small country such as Iceland performing so well? On average, only 27 patients had a resection each year in Iceland, and surgical treatment is certainly centralized. We can only speculate; but at the same time as this is a national material, it is also a report from a single center as only one hospital performed thoracic surgery in Iceland. In other countries, resection rates vary widely among different regions. In England, regional resection rates vary between 3% and 18%; 2 in Denmark, rates vary between 13% and 24%; 3 and in Ireland, the rates varied between 8% and 16% between 1998 and 2001. 7 The largest