Ann Surg Oncol (2011) 18:S226–S227 DOI 10.1245/s10434-010-1307-6
LETTER TO THE EDITOR
In Reply: The Importance of Preoperative Staging with Chest CT Scan in Patients with Colorectal Cancer
TO THE EDITORS: We would like to thank Pavoor et al. for their response to our conclusions and would like to reply to their comments. Our remark concerning ‘‘curative options for synchronous lung metastases are very limited and may be even nonexistent’’ is placed in the context of synchronous lung metastases and is intended to put forward the option of a more aggressive, incurable tumor behavior in synchronous pulmonary metastases. On this issue, Treasure describes that the evidence on benefit of pulmonary metastases treatment in CRC patients is not as solid as it may seem, mentioning tumor biology as a possible relevant factor.1 Lin et al. and Rena et al. both describe the duration between resection of the primary tumor and diagnosis of lung metastases as a significant prognostic factor, a finding that may reflect a relevant difference in tumor biology in synchronous metastases.1–3 Such an adverse outcome in patients with evident synchronous pulmonary metastases was observed in our series. When reviewing additional studies on the outcomes and prognostic factors of pulmonary metastases treatment, relevant limitations can be noted.2–10 All studies invariably are retrospective cohort studies of highly selected patient populations. Also, we do not know what proportion of the CRC population is included in these series; it may be mere collections of exceptional cases. Our study does not intend to answer this specific question, but we consider it a relevant issue in the context of staging of the chest in patients with CRC. Our study describes a prospective, unselected series of patients with colorectal cancer that may result in different conclusions compared with studies that describe selected populations. Our focus was whether routine staging of the chest with CT of all patients with colorectal cancer would be beneficial. For this, we looked at the incidence of synchronous pulmonary metastases (diagnosis before treatment
was 2.5%) and the consequences for the initial treatment plan. In our series of 200 patients, this approach did not result in any benefit or alteration of the treatment plan for the primary tumor, hence our conclusion. The disadvantages that we observed, being the possible unnecessary delay of treatment, harm inflicted by additional diagnostic procedures and prolonged anxiety resulting from finding indeterminate lesions, the costs and radiation exposure in a large population, were considered to outweigh the theoretical advantages that might exist for very few patients. We do agree with the commentators that staging of the chest remains important. However, in our opinion, routine staging with chest CT in all patients is not the answer. First, extensive pulmonary metastases that would imply palliative treatment can be diagnosed with a chest X-ray, and already most patients with incurable metastatic CRC were identified by means of the abdominal CT. Alternative approaches may identify the few patients with relevant small pulmonary metastases. Experimental options that are considered by our group are alternate imaging techniques (such as diffusion weighed MRI) or use of biochemical prognostic markers as a first-line indicator of persistent disease after treatment, such as the CEA index; these approaches may be more specific and less expensive, because they limit the staging chest CT to a selected highrisk population.11,12 We agree that staging with chest CT in patients who are about to undergo major procedures for metastatic CRC, such as extended hepatic resections or peritonectomy with HIPEC for peritoneal carcinomatosis, may be reasonable, as is mentioned in the discussion section. The finding that 10–20% of the indeterminate lesions on the chest CT are indeed pulmonary metastases does give rise to an interesting question.13–15 Factually, we do not know the significance and biological behavior of small pulmonary metastases that are nowadays seen as indeterminate lesions on chest CT. It may be that this is a selected group with a mild clinical course, considering the fact it took on average a long time before the diagnosis was made. This (hypothetical) kind of metastases would not be relevant for the decision on the initial treatment and would therefore not need to be found before treatment. Instead, the detection of this selected kind of metastases may safely be deferred to the phase of follow-up. The conclusion in the comment that diagnosing these lesions on a staging chest CT eventually will result in an improved outcome is not based on any evidence.
Letter to The Editor
To conclude, our findings do not support routine staging of the chest with CT in patients with CRC. It does give lead points on relevant clinical issues that warrant further study. One is how to improve of the accuracy of the staging procedure for the chest. Second is the prognostic significance and biological behavior of pulmonary metastases as observed in unselected CRC populations. Irene Grossmann, MD1, Johannes Avenarius, MD, PhD2, Walter Mastboom, MD, PhD1, and Joost Klaase, MD, PhD1 1 Department of Surgery, Medical Spectrum Twente, Enschede, The Netherlands; 2 Department of Radiology, Medical Spectrum Twente, Enschede, The Netherlands e-mail:
[email protected] Published Online: 28 August 2010 Ó Society of Surgical Oncology 2010
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