Evaluation of molecular targeted cancer drug by changes in tumor marker doubling times

Prognostic Utility of 24-Hour Urinary 5-HIAA Doubling Time in Patients With Neuroendocrine Tumors

OBJECTIVE

New clinical prognostic tools are needed to select the population of patients with neuroendocrine tumors (NETs) that have a high risk of disease progression and disease-specific mortality (DSM). Biochemical biomarker doubling time (DT) is used clinically for prognosis prediction in several solid malignancies. The aim of the current study was to determine whether 24-hour urinary 5-hydroxyindoleacetic acid (5-HIAA) level DT has any prognostic utility in patients with NETs.

METHODS

Patients with NETs were enrolled in a prospective study with comprehensive biochemical analysis. The current analysis included 90 subjects with increasing 5-HIAA levels in two consecutive measurements. DT was calculated using the Schwartz equation. The primary outcome measures were DSM and disease progression.

RESULTS

5-HIAA DT of <434 days was associated with a higher rate of DSM ( P = .02), with positive and negative predictive values for DSM of 75 and 77%, respectively. The difference in DSM was accounted for mainly by patients with small intestine or unknown primary NET ( P = .01). In addition, a shorter 5-HIAA DT in patients with small intestine or unknown primary NET was associated with a higher risk of disease progression both in univariate ( P = .001) and multivariable analyses (hazard ratio, 15.8; 95% confidence interval, 1.3 to 198.0; P = .03).

CONCLUSION

5-HIAA DT may be used as a risk stratification tool in patients with small intestine NET or NET of unknown primary after it is validated in an independent cohort and can assist in identifying patients with a high risk for disease progression and DSM.

ABBREVIATIONS

CT = computed tomography; DSM = disease-specific mortality; DT = doubling time; 5-HIAA = 5-hydroxyindoleacetic acid; MRI = magnetic resonance imaging; NET = neuroendocrine tumor; NETUP = neuroendocrine tumor of unknown primary; PET = positron emission tomography; PFS = progression-free survival; PNET = pancreatic neuroendocrine tumor; ROC = receiver operating characteristic; SINET = small-intestine neuroendocrine tumor.

Drug resistance effects of ribosomal protein L24 overexpression in hepatocellular carcinoma HepG2 cells

BACKGROUND

The morbidity and mortality rate of liver cancer continues to rise in China and advanced cases respond poorly to chemotherapy. Ribosomal protein L24 has been reported to be a potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cell growth of cancer.

MATERIALS AND METHODS

Total RNA of cultured amycin-resistant and susceptible HepG2 cells was isolated, and real time quantitative RT-PCR were used to indicate differences between amycin-resistant and susceptible strains of HepG2 cells. Viability assays were used to determine amycin resistance in RPL24 transfected and control vector and null- transfected HepG2 cell lines.

RESULTS

The ribosomal protein L24 transcription level was 7.7 times higher in the drug-resistant HepG2 cells as compared to susceptible cells on quantitative RT-PCR analysis. This was associated with enhanced drug resistance as determined by methyl tritiated thymidine (3H-TdR) incorporation.

CONCLUSIONS

The ribosomal protein L24 gene may have effects on drug resistance mechanisms in hepatocellular carcinoma HepG2 cells.

Computed tomography follow-up for the detection of hepatocellular carcinoma recurrence after initial radiofrequency ablation: a single-center experience

PURPOSE

Recurrence of hepatocellular carcinoma (HCC) is very common even after curative resection or ablation. This retrospective study compared the radiologic features of recurrent HCC seen by computed tomography (CT) to evaluate our empirical protocol of CT surveillance using 4-month intervals.

MATERIALS AND METHODS

A total of 113 patients who were diagnosed with a first HCC recurrence after radiofrequency (RF) ablation between January 2005 and December 2006 were enrolled at a single center. Definite HCC was defined as hyperattenuation in the arterial phase with washout in the portal venous phase, and a diagnosis of naive and recurrent HCC was based on dynamic CT findings. Recurrent nodules were classified according to the enhancement patterns of previous CT images. The treatment modality for recurrent HCC and survival were evaluated.

RESULTS

One hundred seventy-seven nodules were diagnosed as recurrent HCC: 31 (17.5%) had already been diagnosed on previous CT images as typical HCC, 72 (40.6%) had arterial hypervascularity without washout in the portal venous phase, 21 (11.9%) showed portal venous phase washout without arterial hypervascularity, and no lesions were noted in the remaining 49 (27.7%). Tumor size at recurrence was smaller than 2 cm in diameter in 98 (86.7%) cases. One hundred four patients were treated for recurrent HCC with RF ablation. The 5-year survival rate after recurrence was 49.8%. There was no significant difference in survival among groups divided by the enhancement pattern on the previous CT examination.

CONCLUSIONS

Dynamic CT in 4-month intervals is an acceptable recurrence-monitoring strategy because it detects most recurrent nodules at a stage at which RF ablation is still feasible.