Should indeterminate lung lesions reported on staging CT scans influence the management of patients with colorectal cancer?

Objective The aim of this study was to determine the significance of indeterminate lung lesions reported from staging CT scans on patients with colorectal cancer. Method CT-scan reports of 439 patients were reviewed to identify patients in which indeterminate lung lesion had been reported. The tumour, node, metastasis (TNM) stage of these patients was recorded together with any follow-up scan reports or multidisciplinary team (MDT) discussions regarding these lesions. Results Twenty-three patients had definite lung metastases. Forty-five patients had indeterminate lung lesions. Of these, 22 patients had N1 or N2 disease, 20 had N0 disease and three patients were not operated on due to comorbidity. Of these 45 patients, 30 had further follow-up scans. In 19, the indeterminate lesions were unchanged and were therefore downgraded to benign lesions. The lesions had progressed or new lesions had developed in five. These patients were therefore shown to have metastatic lung disease. All five of these patients had N1 or N2 disease. One patient had a primary rather than metastatic lung lesion. Follow-up scans showed the lesion to be no longer present in five. Of the remainder, One patient declined further follow up. Three patients did not have a follow up scan for reasons not mentioned in their records Two patients were not scanned because further MDT review of the original scans showed that the lesions were not metastases. Four patients died before follow up scans were done. (one postoperative myocardial infarction (MI), one postoperative sepsis, one postoperative cerebrovascular accident (CVA) and one inferior vena cava (IVC) obstruction) Five patients have not yet had follow-up scan at the time of writing. Conclusion Since the introduction of spiral CT scanners, smaller lesions are being seen at the time of preoperative staging. Our study concludes that only a small proportion of indeterminate lung lesions did develop into definite metastases and those that did had node positive disease. Indeterminate lung lesions are not a reason to delay surgery for colorectal cancer.