Liver adenomatosis mimics metastatic liver involvement on FDG-PET/ CT

BACKGROUND

Liver adenomatosis is a very rare disease. In the literature, we were able to find only two case reports documenting the appearance of this disease on PET/CT with 18F-fludeoxyglucose (FDG-PET/CT).

CASE

Numerous liver foci were detected during sonography in a 52-year-old female patient with uncharacteristic pain in the epigastrium without oncological history, with negative oncomarkers and without clinical signs of generalized neoplasia. Complementary MRI examination expressed the suspicion of metastatic origin of the foci, and FDG-PET/CT was indicated in order to identify the primary tumour and assess the extent of the disease. A whole-body FDG-PET/CT examination showed multiple (> 20) markedly hypermetabolic liver foci with 3-20 mm in diameter, reaching a relative accumulation of SUVBWmax = 13, together with several ametabolic cysts; elsewhere in the scope of the examination, focally pathologically increased metabolic activity was not evident. Subsequently, the patient underwent a biopsy targeted at one of the hypermetabolic liver foci with the finding of HNF 1A inactivated variant of hepatocellular adenoma; primary or secondary malignancy was not demonstrated. Considering the histological findings and the large number of liver foci, the final diagnosis of liver adenomatosis was set. The patient remains under continuous observation.

CONCLUSION

Adenomatous foci were markedly hypermetabolic during FDG-PET/CT examination and could not be distinguished from tumour metastases by this method. Our finding is consistent with two other observations we were able to find in the literature.

Final results from PRIME: randomized phase III study of panitumumab with FOLFOX4 for first-line treatment of metastatic colorectal cancer

BACKGROUND

The Panitumumab Randomized trial In combination with chemotherapy for Metastatic colorectal cancer to determine Efficacy (PRIME) demonstrated that panitumumab-FOLFOX4 significantly improved progression-free survival (PFS) versus FOLFOX4 as first-line treatment of wild-type (WT) KRAS metastatic colorectal cancer (mCRC), the primary end point of the study.

PATIENTS AND METHODS

Patients were randomized 1:1 to panitumumab 6.0 mg/kg every 2 weeks + FOLFOX4 (arm 1) or FOLFOX4 (arm 2). This prespecified final descriptive analysis of efficacy and safety was planned for 30 months after the last patient was enrolled.

RESULTS

A total of 1183 patients were randomized. Median PFS for WT KRAS mCRC was 10.0 months [95% confidence interval (CI) 9.3-11.4 months] for arm 1 and 8.6 months (95% CI 7.5-9.5 months) for arm 2; hazard ratio (HR) = 0.80; 95% CI 0.67-0.95; P = 0.01. Median overall survival (OS) for WT KRAS mCRC was 23.9 months (95% CI 20.3-27.7 months) for arm 1 and 19.7 months (95% CI 17.6-22.7 months) for arm 2; HR = 0.88; 95% CI 0.73-1.06; P = 0.17 (68% OS events). An exploratory analysis of updated survival (>80% OS events) was carried out which demonstrated improvement in OS; HR = 0.83; 95% CI 0.70-0.98; P = 0.03 for WT KRAS mCRC. The adverse event profile was consistent with the primary analysis.

CONCLUSIONS

In WT KRAS mCRC, PFS was improved, objective response was higher, and there was a trend toward improved OS with panitumumab-FOLFOX4, with significant improvement in OS observed in an updated analysis of survival in patients with WT KRAS mCRC treated with panitumumab + FOLFOX4 versus FOLFOX4 alone (P = 0.03). These data support a positive benefit-risk profile for panitumumab-FOLFOX4 for patients with previously untreated WT KRAS mCRC. KRAS testing is critical to select appropriate patients for treatment with panitumumab.