A new NIHR Signal showcases the findings of annitial investigation which includes whole-body magnetic resonance imaging (MRI) is as good as standard pathways for detecting metastatic disease in adults with newly diagnosed colorectal cancer. This NIHR-funded study also found that whole-body MRI reduces the number of investigations needed, the length of the staging process, and costs less than standard pathways.
The treatment options for colorectal cancer depend on the stage of the cancer. For example, if a patient has metastatic disease (secondary tumours in other parts of the body), the aims of surgery and chemotherapy can be different. So, an accurate staging process is very important.
Current NICE guidance recommends a sequence of investigations for staging, with MRI only recommended after biopsies and other imaging investigations. This study suggests that MRI could be used earlier in the process, instead of the currently recommended investigations. However, any changes to guidance would need to take into account the availability of this resource (Source: NIHR).
Whole-body MRI (WB-MRI) could be an alternative to multimodality staging of colorectal cancer, but its diagnostic accuracy, effect on staging times, number of tests needed, cost, and effect on treatment decisions are unknown. We aimed to prospectively compare the diagnostic accuracy and efficiency of WB-MRI-based staging pathways with standard pathways in colorectal cancer.
The Streamline C trial was a prospective, multicentre trial done in 16 hospitals in England. Eligible patients were 18 years or older, with newly diagnosed colorectal cancer. Exclusion criteria were severe systemic disease, pregnancy, contraindications to MRI, or polyp cancer. Patients underwent WB-MRI, the result of which was withheld until standard staging investigations were complete and the first treatment decision made. The multidisciplinary team recorded its treatment decision based on standard investigations, then on the WB-MRI staging pathway (WB-MRI plus additional tests generated), and finally on all tests. The primary outcome was difference in per-patient sensitivity for metastases between standard and WB-MRI staging pathways against a consensus reference standard at 12 months, in the per-protocol population. Secondary outcomes were difference in per-patient specificity for metastatic disease detection between standard and WB-MRI staging pathways, differences in treatment decisions, staging efficiency (time taken, test number, and costs), and per-organ sensitivity and specificity for metastases and per-patient agreement for local T and N stage. This trial is registered with the International Standard Randomised Controlled Trial registry, number ISRCTN43958015, and is complete.
Between March 26, 2013, and Aug 19, 2016, 1020 patients were screened for eligibility. 370 patients were recruited, 299 of whom completed the trial; 68 (23%) had metastasis at baseline. Pathway sensitivity was 67% (95% CI 56 to 78) for WB-MRI and 63% (51 to 74) for standard pathways, a difference in sensitivity of 4% (−5 to 13, p=0·51). No adverse events related to imaging were reported. Specificity did not differ between WB-MRI (95% [95% CI 92–97]) and standard pathways (93% [90–96], p=0·48). Agreement with the multidisciplinary team’s final treatment decision was 96% for WB-MRI and 95% for the standard pathway. Time to complete staging was shorter for WB-MRI (median, 8 days [IQR 6–9]) than for the standard pathway (13 days [11–15]); a 5-day (3–7) difference. WB-MRI required fewer tests (median, one [95% CI 1 to 1]) than did standard pathways (two [2 to 2]), a difference of one (1 to 1). Mean per-patient staging costs were £216 (95% CI 211–221) for WB-MRI and £285 (260–310) for standard pathways.
WB-MRI staging pathways have similar accuracy to standard pathways and reduce the number of tests needed, staging time, and cost.
NIHR Whole-body MRI is effective for identifying metastatic disease in colorectal cancer patients
Read the full journal article from The Lancet Gastroenterology & Hepatology
Taylor, S.A . et al | 2019| Diagnostic accuracy of whole-body MRI versus standard imaging pathways for metastatic disease in newly diagnosed colorectal cancer: the prospective Streamline C trial | The Lancet Gastroenterology & Hepatology | DOI:https://doi.org/10.1016/S2468-1253(19)30056-1