Increased Incidence of Second Primary Pancreatic Cancer in Patients with Prior Colorectal Cancer: A Population-Based US Study

Development and validation of a competing risk model for second primary pancreatic ductal adenocarcinoma: A population-based study

Background

With advances in early diagnosis and treatment, the number of cancer survivors continues to grow, and more and more cancer survivors face the threat of second primary cancer (SPM). Second primary pancreatic ductal adenocarcinoma (spPDAC) is an important subclass of SPM, but its prognostic characteristics are poorly understood.

Methods

A total of 5,439 spPDAC samples and 67,262 primary pancreatic ductal adenocarcinoma (pPDAC) samples were extracted from the SEER database for this study. Survival differences between spPDAC and pPDAC samples were compared using Kaplan–Meier curves and log-rank tests. The Fine and Gray proportional subdistributed hazard method was used to analyze potential associations between clinical variables and pancreatic ductal adenocarcinoma-specific death (PDACSD) and death from other causes. After that, the clinical variables significantly related to PDACSD were screened out to construct a competing risk nomogram, which was used to evaluate the probability of the occurrence of PDACSD. The C-index was used to evaluate the discriminative ability of the model. The area under the curve (AUC) was used to verify the discrimination of the model. The calibration curve was used to verify the calibration of the model. Decision curve analysis (DCA) was used to validate the clinical utility of the model.

Results

Compared with patients with spPDAC, the pPDAC sample had a better prognosis (p = 0.0017). Across all spPDAC samples, the three most common sites of first-present cancer were the prostate, breast, and digestive system. Age (p < 0.001), race (p = 0.006), interval (p = 0.016), location (p < 0.001), T stage (p = 0.003), M stage (p < 0.001), chemotherapy (p < 0.001), and radiotherapy (p = 0.006) were the clinical variables associated with PDACSD screened by multivariate competing risks analysis. The concordance index values for the training and validation sets were 0.665 (95% CI, 0.655, 0.675) and 0.666 (95% CI, 0.650, 0.682), respectively. AUC, calibration curve, and DCA indicated that the model we constructed had good discrimination, calibration, and clinical utility.

Conclusions

In conclusion, we first analyzed the impact of previous cancer history on prognosis. We then constructed a competing risk model that can predict the probability of developing PDACSD in spPDAC. This model has good discriminative ability, calibration, and clinical practicability and has certain guiding value for clinical decision-making.

Analysis of the methylation of CpG islands in the CDO1, TAC1 and CHFR genes in pancreatic ductal cancer

No difference in the gene methylation status of tumor-suppression genes between pancreatic cancer tissues and adjacent non-cancer tissues is observed. The present study investigated whether the promoter CpG islands of the cysteine dioxygenase 1 (CDO1), tachykinin precursor 1 (TAC1) and checkpoint with forkhead and ring finger domains (CHFR) genes were methylated in pancreatic cancer and adjacent non-cancerous pancreatic tissue in order to determine if they could be considered as markers for the detection of pancreatic cancer. A total of 38 Formalin-fixed and paraffin-embedded pancreatic adenocarcinoma tissues and their adjacent non-cancerous specimens from patients with pancreatic cancer, as well as 9 non-cancerous pancreatic samples from patients without pancreatic adenocarcinoma were obtained following surgical resection. The hypermethylation of CpG islands was detected using a methylation-specific quantitative PCR. The methylation values were calculated using the ∆Cq method and were expressed as 2^−ΔCq. The 2^−ΔCq value of the CDO1 promoter from pancreatic adenocarcinoma specimens was significantly higher compared with that of adjacent non-cancerous and tumor-free pancreatic tissues (P<0.0001 and P=0.0008, respectively). The 2^−ΔCq value of the TAC1 promoter of pancreatic adenocarcinoma was also significantly higher compared with that of adjacent non-cancerous tissues and tumor-free pancreatic samples (both P<0.0001). However, there was no significant difference in the 2^−ΔCq value of the CHFR promoter among the pancreatic cancer, adjacent non-cancer tissue and tumor-free pancreatic samples. Furthermore, 12 out of the 38 pancreatic adenocarcinoma cases (31.6%) presented some methylation in the CHFR promoter. The results from Kaplan-Meier analysis between CHFR promoter methylation values and the clinicopathological characteristics of patients with pancreatic adenocarcinoma demonstrated that CHFR promoter methylation was significantly associated with lymph node metastasis. The methylation values of CDO1 and TAC1 promoters in cancer tissues were higher compared with adjacent tissues. However, whether hypermethylation of CDO1 and TAC1 promoters may serve as a biomarker in the diagnosis of pancreatic adenocarcinoma remains unclear.

Outcomes in patients with pancreatic cancer as a secondary malignancy: a retrospective single-institution study

PURPOSE

This study aimed to evaluate the clinicopathological features and oncological outcomes of pancreatic cancer (PC) patients with prior malignancies (2nd primary PC) compared with those of patients without any prior malignancies in their history (1st primary PC).

METHODS

We retrospectively reviewed clinical data from 185 PC patients undergoing surgical resection. Patients were divided into the 1st and 2nd primary PC groups.

RESULTS

Forty-three patients (23.2%) had a history of prior malignancy. The 2nd primary PC group was significantly older than the 1st primary PC group (mean, 72.1 vs. 65.9 years, respectively, P < 0.001) and was more frequently asymptomatic compared to the 1st primary PC group (67.4 vs. 31.0%, respectively, P < 0.001). The tumor size was larger, and extrapancreatic nerve plexus invasion, venous invasion, and lymph node metastasis were more frequently observed in the 1st primary PC group. The rate of adjuvant therapy administration was lower in 2nd primary PC patients (72.5 vs. 51.2%, P = 0.009). In the survival analysis, no significant difference in overall or disease-free survival was found between the two groups (16.8 vs. 16.4 months, P = 0.725, and 8.7 vs. 9.3 months, P = 0.284, respectively).

CONCLUSION

Despite significant surveillance bias, such as earlier detection in 2nd primary PC, the outcomes of patients with 2nd primary PC were comparable to those of patients with 1st primary PC. Further investigation with a larger sample size and matching for patient age and tumor stage in both groups is needed to elucidate the biological features of 2nd primary PC.

Incidence and Mortality Rates of Second Pancreatic Cancer Among Survivors of Digestive Cancers: A Nationwide Population-Based Study

OBJECTIVES

We analyzed the incidence and mortality rates of second pancreatic ductal adenocarcinoma (PDAC) among survivors of digestive cancers in South Korea.

METHODS

We evaluated data from the Korea National Health Insurance to identify individuals with digestive cancers in 2005 to 2015. The standardized incidence ratios (SIRs) of second PDACs and survival rates were evaluated.

RESULTS

Among 772,534 patients with first digestive cancers, 1696 (0.22%) developed second PDACs. The incidence of second PDACs increased until 10 years since the first cancer diagnosis. Patients with biliary tract cancers (BTCs) showed a higher incidence of second PDACs than did those with gastrointestinal cancers or hepatocellular carcinoma. In ages 20 to 49 years, SIRs (95% confidence interval) were higher in survivors of hepatocellular carcinoma (3.08; 1.04-3.08), gastric cancer (3.40; 1.90-3.40), colorectal cancer (5.00; 2.75-5.00), gallbladder cancer (58.52; 11.81-58.52), intrahepatic cholangiocarcinoma (86.99; 1.73-86.99), extrahepatic cholangiocarcinoma (89.41; 27.42-89.41), and ampulla of Vater cancer (156.78; 48.08-156.78). In ages 50 to 64 years, colorectal cancer (1.42; 1.04-1.42), gastric cancer (1.66; 1.29-1.66), and BTCs revealed higher SIRs. In ages more than 65 years, SIR was increased only in BTCs. Second PDACs revealed a more favorable prognosis than first PDACs.

CONCLUSIONS

Careful surveillance for second PDACs after curative treatment of BTCs and colorectal cancers should be considered.

Gastrointestinal cancer risk in patients with a family history of gastrointestinal cancer

Background/Aims

This study was performed to evaluate the relationship between family history of gastrointestinal (GI) cancers and incidence of any GI cancer in the Korean population.

Methods

Between January 2015 and July 2016, 711 GI cancer patients and 849 controls in 16 hospitals in Korea were enrolled. Personal medical histories, life styles, and family history of GI cancers were collected via questionnaire.

Results

There was a significant difference in the incidence of family history of GI cancer between GI cancer patients and controls (p=0.002). Patients with family history of GI cancer tended to be diagnosed as GI cancer at younger age than those without family history (p=0.016). The family members of GI cancer patients who were diagnosed before 50 years of age were more frequently diagnosed as GI cancer before the age of 50 years (p=0.017). After adjusting for major confounding factors, age (adjusted odds ratio [AOR] 1.065, 95% confidence interval [CI]; 1.053-1.076), male gender (AOR 2.270, 95% CI; 1.618-3.184), smoking (AOR 1.570, 95% CI; 1.130-2.182), and sibling's history of GI cancer (AOR 1.973, 95% CI; 1.246-3.126) remained independently associated with GI cancers.

Conclusions

GI cancer patients tended to have a first relative with a history of concordant GI cancer. Personal factors (old age and male) and lifestyle (smoking) contribute to the development of GI cancer, independently. Individuals with high risk for GI cancers may be advised to undergo screening at an earlier age.

Assessment of the Risk of Colorectal Cancer Survivors Developing a Second Primary Pancreatic Cancer

BACKGROUND/AIMS

We aimed to investigate the incidence of second primary pancreatic cancer (PC) after colorectal cancer (CRC) and to identify risk factors associated with subsequent PC.

METHODS

The observed incidence of a subsequent PC in patients with CRC was standardized using a population with CRC from the Korean Central Cancer Registry (KCCR). The expected incidence rate of PC was obtained by assuming that the select group experienced the same cancer incidence as the corresponding general population in the KCCR.

RESULTS

The registry included 4,822 patients with CRC aged 45 to 74 years, representing 16,725.1 person-years of follow-up. Thirteen patients (0.3%) were diagnosed with a subsequent PC, and the overall age-adjusted incidence of second primary PC was 269.6 per 100,000 cases. In contrast, the overall incidence of primary PC in the general population was 18.68 per 100,000 individuals. The standardized incidence ratio of subsequent PC was 14.44, which was significantly higher in patients with CRC than in the general population. Sex, diabetes mellitus, smoking, body mass index, and a history of receiving chemotherapy as a treatment for CRC did not increase the risk of subsequent development of PC.

CONCLUSIONS

The risk of a second primary PC was higher in patients with CRC. Further studies are needed to identify the risk factors and generate a screening strategy for cancer survivors.

Quantifying the Genetic Correlation between Multiple Cancer Types

Background: Many cancers share specific genetic risk factors, including both rare high-penetrance mutations and common SNPs identified through genome-wide association studies (GWAS). However, little is known about the overall shared heritability across cancers. Quantifying the extent to which two distinct cancers share genetic origin will give insights to shared biological mechanisms underlying cancer and inform design for future genetic association studies.Methods: In this study, we estimated the pair-wise genetic correlation between six cancer types (breast, colorectal, lung, ovarian, pancreatic, and prostate) using cancer-specific GWAS summary statistics data based on 66,958 case and 70,665 control subjects of European ancestry. We also estimated genetic correlations between cancers and 14 noncancer diseases and traits.Results: After adjusting for 15 pair-wise genetic correlation tests between cancers, we found significant (P < 0.003) genetic correlations between pancreatic and colorectal cancer (rg = 0.55, P = 0.003), lung and colorectal cancer (rg = 0.31, P = 0.001). We also found suggestive genetic correlations between lung and breast cancer (rg = 0.27, P = 0.009), and colorectal and breast cancer (rg = 0.22, P = 0.01). In contrast, we found no evidence that prostate cancer shared an appreciable proportion of heritability with other cancers. After adjusting for 84 tests studying genetic correlations between cancer types and other traits (Bonferroni-corrected P value: 0.0006), only the genetic correlation between lung cancer and smoking remained significant (rg = 0.41, P = 1.03 × 10-6). We also observed nominally significant genetic correlations between body mass index and all cancers except ovarian cancer.Conclusions: Our results highlight novel genetic correlations and lend support to previous observational studies that have observed links between cancers and risk factors.Impact: This study demonstrates modest genetic correlations between cancers; in particular, breast, colorectal, and lung cancer share some degree of genetic basis. Cancer Epidemiol Biomarkers Prev; 26(9); 1427-35. ©2017 AACR.

Clinical characteristics of second primary pancreatic cancer

Purpose

Several studies reported the increased risk of second primary pancreatic ductal adenocarcinoma (2nd PDAC) in cancer survivors. However, data on the characteristics of 2nd PDAC are insufficient.

Methods

This retrospective cohort study included 1759 patients with PDAC. They were classified as having 2nd PDAC or first primary PDAC (1st PDAC) according to a prior diagnosed cancer of different origin, at least 6 months before PDAC diagnosis.

Results

There were 110 patients (6.4%) with 2nd PDAC and 1606 (93.6%) patients with 1st PDAC. Patients with 2nd PDAC presented with older age (66.5 vs. 62.2 years, p < 0.001) and higher rate of resectability (26.4% vs. 15.9%, p = 0.004) at diagnosis than those with 1st PDAC. Multivariate analysis without considering resectable status showed that 2nd PDAC (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.56–0.94, p = 0.016) was associated with better overall survival. After adjusting for resectable status, however, 2nd PDAC (HR 0.85, 95% CI 0.66–1.09, p = 0.198) was no longer associated with overall survival. When subgroups were separately analyzed according to initial treatment modality, the effectiveness of surgery and chemotherapy were similar between 2nd and 1st PDAC (33.1 vs. 28.5 months, p = 0.860 and 10.8 vs. 10.7 months, p = 0.952).

Conclusions

The proportion of resectable cases was significantly higher in 2nd PDAC. When surgery with curative aim was possible, the overall survival was increased even in patients with 2nd PDAC. These results suggest the importance of screening for second primary cancer in cancer survivors.