Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2014

Prognostic value of c-Met overexpression in hepatocellular carcinoma: a meta-analysis and review

The overexpression of c-Met protein has been detected in hepatocellular carcinoma (HCC). However, its prognostic impact remains uncertain. We performed this meta-analysis to evaluate the prognostic value of c-Met overexpression in patients who underwent curative surgical resection for HCC. A systematic computerized search of the electronic databases was carried out. From 5 studies, 1,408 patients who underwent surgical resection for HCC were included in the meta-analysis. Compared with patients with HCC having low c-Met expression, patients with c-Met-high tumor showed significantly worse relapse-free survival (hazard ratio = 1.26 [95% confidence interval, 1.02–1.56], P = 0.03) and overall survival (hazard ratio = 1.16 [95% confidence interval, 1.03–1.31], P = 0.01). In conclusion, our meta-analysis indicates that c-Met overexpression is a significant adverse prognostic factor for recurrence and survival in patients who underwent surgical resection for HCC.

External Validation of a Gastric Cancer Nomogram Derived from a Large-volume Center Using Dataset from a Medium-volume Center

Purpose

Recently, a nomogram predicting overall survival after gastric resection was developed and externally validated in Korea and Japan. However, this gastric cancer nomogram is derived from large-volume centers, and the applicability of the nomogram in smaller centers must be proven. The purpose of this study is to externally validate the gastric cancer nomogram using a dataset from a medium-volume center in Korea.

Materials and Methods

We retrospectively analyzed 610 patients who underwent radical gastrectomy for gastric cancer from August 1, 2005 to December 31, 2011. Age, sex, number of metastatic lymph nodes (LNs), number of examined LNs, depth of invasion, and location of the tumor were investigated as variables for validation of the nomogram. Both discrimination and calibration of the nomogram were evaluated.

Results

The discrimination was evaluated using Harrell's C-index. The Harrell's C-index was 0.83 and the discrimination of the gastric cancer nomogram was appropriate. Regarding calibration, the 95% confidence interval of predicted survival appeared to be on the ideal reference line except in the poorest survival group. However, we observed a tendency for actual survival to be constantly higher than predicted survival in this cohort.

Conclusions

Although the discrimination power was good, actual survival was slightly higher than that predicted by the nomogram. This phenomenon might be explained by elongated life span in the recent patient cohort due to advances in adjuvant chemotherapy and improved nutritional status. Future gastric cancer nomograms should consider elongated life span with the passage of time.

Validity of self-reported cancer history in the health examinees (HEXA) study: A comparison of self-report and cancer registry records

PURPOSE

To assess the validity of the cohort study participants' self-reported cancer history via data linkage to a cancer registry database.

METHODS

We included 143,965 participants from the Health Examinees (HEXA) study recruited between 2004 and 2013 who gave informed consent for record linkage to the Korean Central Cancer Registry (KCCR). The sensitivity and the positive predictive value of self-reported histories of cancer were calculated and 95% confidence intervals were estimated.

RESULTS

A total of 4,860 participants who had at least one record in the KCCR were included in the calculation of sensitivity. In addition, 3,671 participants who reported a cancer history at enrollment were included in the calculation of positive predictive value. The overall sensitivity of self-reported cancer history was 72.0%. Breast cancer history among women showed the highest sensitivity (81.2%), whereas the lowest sensitivity was observed for liver cancer (53.7%) and cervical cancer (52.1%). The overall positive predictive value was 81.9%. The highest positive predictive value was observed for thyroid cancer (96.1%) and prostate cancer (96.1%), and the lowest was observed for cervical cancer (43.7%).

CONCLUSION

The accuracy of self-reported cancer history varied by cancer site and may not be sufficient to ascertain cancer incidence, especially for cervical and bladder cancers.

Prognostic value of smoking status in non-small-cell lung cancer patients treated with immune checkpoint inhibitors: a meta-analysis

Immune checkpoint inhibitors (ICIs) have emerged as a new treatment option for patients with advanced non-small-cell lung cancer (NSCLC). Some studies with ICIs in NSCLC suggested that smoking history was associated with improved survival outcomes. We conducted this meta-analysis to investigate if survival benefits of ICIs in patients with advanced NSCLC are different according to smoking status. Electronic databases were searched for eligible studies. We included randomized controlled trials with the data of survival outcomes and extracted progression-free survival (PFS) or overall survival (OS) stratified by smoking status. From 6 studies, 2,389 ever-smokers and 413 never-smokers were included in the meta-analysis. In first-line treatment setting, ICIs tended to improve PFS in patients with smoking history (HR = 0.85 [95% CI, 0.71–1.10], P = 0.07). For never-smokers with advanced NSCLC, chemotherapy, not ICIs, was significantly associated with improvement of PFS (HR = 2.30 [95% CI, 1.23–4.28], P = 0.009). In more than second-line setting, ICIs significantly prolonged OS over that with chemotherapy in ever-smokers (HR = 0.70 [95% CI, 0.63–0.79], P < 0.00001). For never-smokers with NSCLC, however, ICIs failed to significantly improve OS (HR = 0.79 [95% CI, 0.59–1.06], P = 0.12). In conclusion, this meta-analysis indicates that ICIs can prolong survival over that with chemotherapy in ever-smokers with advanced NSCLC. However, ICIs failed to improve survival in never-smokers. These results suggest that smoking status may be a predictive marker for survival benefits to ICIs.

Strategies for Appropriate Patient-centered Care to Decrease the Nationwide Cost of Cancers in Korea

In terms of years of life lost to premature mortality, cancer imposes the highest burden in Korea. In order to reduce the burden of cancer, the Korean government has implemented cancer control programs aiming to reduce cancer incidence, to increase survival rates, and to decrease cancer mortality. However, these programs may paradoxically increase the cost burden. For examples, a cancer screening program for early detection could bring about over-diagnosis and over-treatment, and supplying medical services in a paternalistic manner could lead to defensive medicine or futile care. As a practical measure to reduce the cost burden of cancer, appropriate cancer care should be established. Ensuring appropriateness requires patient-doctor communication to ensure that utility values are shared and that autonomous decisions are made regarding medical services. Thus, strategies for reducing the cost burden of cancer through ensuring appropriate patient-centered care include introducing value-based medicine, conducting cost-utility studies, and developing patient decision aids.

Survival benefit of anti-angiogenic agents in patients with previously treated advanced gastric or gastroesophageal junction cancer: a meta-analysis

There is a debate as to whether anti-angiogenic molecular agents can produce survival benefits in patients with previously treated advanced gastric cancer (GC) or gastroesophageal junction cancer (GEJC). We performed this meta-analysis of randomized trials to evaluate the survival outcomes of an anti-angiogenic agent versus placebo in the salvage treatment of advanced GC or GEJC. Electronic databases were searched for eligible studies. From the four studies, 910 patients with previously treated advanced GC or GEJC were included in the meta-analysis. Compared with placebo, anti-angiogenic targeted agents significantly improved progression-free survival (hazard ratio = 0.37 [95% confidence interval, 0.26-0.53], P < 0.00001). In terms of overall survival, anti-angiogenic agents induced 36% reduction in the risk for death (hazard ratio = 0.64 [95% confidence interval, 0.48-0.86], P = 0.002). In conclusion, this meta-analysis demonstrates that anti-angiogenic agents can prolong survival in patients with previously treated advanced GC or GEJC. This finding suggests that anti-angiogenic therapy can be a considerable option in patients who are not candidates for further chemotherapy.

Molecular Basis of Alcohol-Related Gastric and Colon Cancer

Many meta-analysis, large cohort studies, and experimental studies suggest that chronic alcohol consumption increases the risk of gastric and colon cancer. Ethanol is metabolized by alcohol dehydrogenases (ADH), catalase or cytochrome P450 2E1 (CYP2E1) to acetaldehyde, which is then further oxidized to acetate by aldehyde dehydrogenase (ALDH). Acetaldehyde has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen to humans. The acetaldehyde level in the stomach and colon is locally influenced by gastric colonization by Helicobacter pylori or colonic microbes, as well as polymorphisms in the genes encoding tissue alcohol metabolizing enzymes, especially ALDH2. Alcohol stimulates the uptake of carcinogens and their metabolism and also changes the composition of enteric microbes in a way to enhance the aldehyde level. Alcohol also undergoes chemical coupling to membrane phospholipids and disrupts organization of tight junctions, leading to nuclear translocation of β-catenin and ZONAB, which may contributes to regulation of genes involved in proliferation, invasion and metastasis. Alcohol also generates reactive oxygen species (ROS) by suppressing the expression of antioxidant and cytoprotective enzymes and inducing expression of CYP2E1 which contribute to the metabolic activation of chemical carcinogens. Besides exerting genotoxic effects by directly damaging DNA, ROS can activates signaling molecules involved in inflammation, metastasis and angiogenesis. In addition, alcohol consumption induces folate deficiency, which may result in aberrant DNA methylation profiles, thereby influencing cancer-related gene expression.

N of 1 case reports of exceptional responders accrued from pancreatic cancer patients enrolled in first-in-man studies from 2002 through 2012

PURPOSE

To identify exceptional responders among patients with advanced pancreatic cancer enrolled in first-in-man (FIM) studies.

METHODS

A Scopus search identified 66 FIM studies that enrolled at least one patient with advanced pancreatic cancer between 2002-2012. Descriptive statistics were used to summarize categorical variables. We also screened CRKL amplifications in the FoundationOne™ pancreatic cancer database.

RESULTS

Most FIM studies included targeted therapies (76 vs. 24%). The most common targeted therapy involved cell cycle inhibitors (24%). Pharmacodynamic analyses were more frequently done in trials with targeted therapies (70 vs. 31%, p=0.006). Response rates were similar. Treatment-related death was 0.5%. Skin, cardiovascular and metabolic grade 3-4 toxicities were more frequent with targeted therapies. Four exceptional responses were identified including a complete response to bosutinib (Src Inhibitor) and partial responses to trametinib (MEK inhibitor) (2 patients) and CHR-3996 (histone deacetylase inhibitor). We found that CRKL amplifications, a potential biomarker for Src inhibitors, are present in 1% of PDA.

CONCLUSIONS

We retrospectively identified extraordinary responses among patients with advanced PDA enrolled in FIM studies with Src, HDAC and MEK inhibitors. We identified CRKL amplifications are present in 1% of PDA and need to be evaluated as predictive biomarker for Src inhibitors.