Second primary malignancy risk among patients with gastric cancer: a nationwide population-based study in Taiwan

Incidence and Characteristics of Multiple Primary Cancers: A 20-Year Retrospective Study of a Single Cancer Center in Korea

Rising cancer survival rates have led to an increased risk of multiple primary cancers (MPCs). Data on MPCs in South Korea are limited. This study aimed to address incidence and clinical characteristics of MPCs in a single cancer center in Korea during a 20-year period. We retrospectively analyzed 96,174 cancer patients at the Korea Cancer Center Hospital between 2003 and 2022, identifying 2167 patients with metachronous MPCs based on Surveillance, Epidemiology, and End Results SEER criteria. We categorized patients by cancer type (15 major solid cancer groups and 3 major hematologic cancer groups), including pathological diagnosis, assessed latency periods, and relative risks (RRs) for developing MPCs. The overall MPC incidence was 2.3%. Breast cancer (15.7%) was the most common primary cancer, and lung cancer (15.2%) was the most frequent second primary cancer. The median latency period for second primary cancers was 4.1 years. Decreasing latency periods for third and fourth primary cancers were observed (2.1 years and 1.6 years, respectively). Most cancers maintained their dominant pathological type despite notable changes in the prevalence of specific pathologies for certain types of second primaries. Lymphoma showed the highest RR (2.1) for developing MPCs. Significant associations were found between specific primary and subsequent cancers, including breast-ovary, thyroid-breast, stomach-pancreas, colorectal-head and neck, lung-prostate, and lymphoma-myeloid neoplasms. These findings contribute to a better understanding of MPC occurrence. They can inform future research on their etiology and development of improved management strategies.

Incidence, risk and prognosis of second primary malignancy of patients with gastric adenocarcinoma

Due to the long-term low survival rates of gastric adenocarcinoma (GAC) patients, the occurrence and prognosis of second primary malignancies (SPMs) are often underreported and overlooked as a significant concern.To date, only a few studies have addressed this issue in the context of GAC. These studies, however, are limited by their small patient cohorts and lack of substantial, meaningful findings. Our study aims to fill this gap by investigating the incidence, risk factors, and prognostic significance of SPMs among GAC survivors. Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, we analysed data from patients diagnosed with GAC between 2000 and 2020. The study employs the standardized incidence ratio (SIR) to assess the relative risk of SPMs, competing risk regression to identify risk factors for SPM development after GAC, and Kaplan-Meier and COX regression analyses for survival outcomes. Out of 44,041 GAC patients analyzed, 2,032 (4.3%) developed SPMs, with a median latency period of 36 months. The incidence of SPMs was significantly higher in GAC patients (SIR 1.36, 95% CI 1.32-1.4, EAR 53.57) compared to the general population. Key factors including older age, sex, tumor grade, summary stage, and history of surgical and radiation therapy were related to the higher risk of developing SPMs following GAC. Interestingly, GAC patients without SPMs exhibited poorer overall survival compared to those with SPMs. Age, summary stage, and surgical history were identified as independent prognostic factors for GAC patients with SPMs. This comprehensive analysis underscores the necessity of vigilant monitoring and tailored follow-up for SPMs in GAC survivors, highlighting the study's contribution to enhancing GAC survivors care strategies.

Nomogram for predicting survival of patients with gastric cancer and multiple primary malignancies: a real-world retrospective analysis using the Surveillance, Epidemiology and End Results database

OBJECTIVES

Gastric cancer combined with multiple primary malignancies (GCM) is increasingly common. This study investigated GCM clinical features and survival time.

METHODS

Patients with GCM and GC only (GCO) were selected from the Surveillance, Epidemiology and End Results (SEER) database. Survival was compared between GCM and GCO groups using propensity score matching. Then, the GCM group was divided into a training cohort and a validation cohort. These cohorts were used to establish a nomogram for survival prediction in patients with GCM.

RESULTS

Survival time was significantly longer in the GCM group than in the GCO group. All-subsets regression was used to identify four variables for nomogram establishment: age, gastric cancer sequence, N stage, and surgery. The concordance index and time-dependent receiver operating characteristic curve indicated that the nomogram had favorable discriminative ability. Calibration plots of predicted and actual probabilities showed good consistency in both the training and validation cohorts. Decision curve analysis and risk stratification showed that the nomogram was clinically useful; it had favorable discriminative ability to recognize patients with different levels of risk.

CONCLUSIONS

Compared with GCO, GCM is a relatively indolent malignancy. The nomogram developed in this study can help clinicians to assess GCM prognosis.

Risk and prediction of multiple primary malignancies after early gastric cancer

BACKGROUND

Patients with early gastric cancer have increased risk of developing multiple primary malignancies (MPM) due to improved survival rates. The purpose of this study was to evaluate the clinicopathological features of MPM and to generate a useful tool for predicting the development of MPM after early gastric cancer.

METHODS

We selected 1025 early gastric cancer patients with complete medical records for a retrospective analysis. The Cox proportional risk regression model was used to analyze the independent risk factors for the development of MPM in early gastric cancer. RStudio software was used to compare the OS of early gastric cancer patients with and without MPM, and a nomogram was established to predict the probability of MPM 1-, 2-, 3-year after early gastric cancer. The predictive effectiveness of the nomogram was evaluated by the C-index and calibration curve. Decision curve analysis (DCA) measured the applicability of the nomogram to clinical practice.

RESULTS

Of the 1025 patients with early gastric cancer, 66 patients (6.4%) had 69 primary cancers other than early gastric cancer. They had a median follow-up of 41 months, and their cumulative incidence of MPM was 4.9%, 5.4% and 5.9% after 1-, 2-, and 3- year, respectively. Oesophageal cancer was the most frequently detected MPM, followed by lung and colorectal cancers. Male (p=0.038), age ≥65 years (p=0.003), smoking history (p=0.036), and lymph node metastasis (p=0.013) were independent risk factors for MPM in patients with early gastric cancer. Patients with early gastric cancer with MPM had a worse OS prognosis than patients with early gastric cancer without MPM (p<0.001). The internally validated nomogram predicted the probability of developing MPM after early gastric cancer (C index= 0.697). The calibration chart showed that the predicted probability of MPM in early gastric cancer was similar to the observed result, and the DCA showed strong clinical practicability.

CONCLUSION

After the diagnosis and treatment of early gastric cancer, we should be alert to the possibility of MPM and perform regular and careful monitoring.

Risk prediction of second primary malignancies in primary colorectal neuroendocrine neoplasms patients: a population-based study

PURPOSE

In this study, we aimed to identify risk factors for developing second primary malignancies (SPMs) in colorectal neuroendocrine neoplasms (NENs) patients and develop a competing-risk nomogram to predict SPMs' probabilities quantitatively.

METHODS

Patients with colorectal NENs were retrospectively collected from the Surveillance, Epidemiology, and End Results (SEER) database during 2000-2013. Potential risk factors for SPMs' occurrence in colorectal NENs' patients were identified by the Fine and Gray's proportional sub-distribution hazards model. Then, a competing-risk nomogram was constructed to quantify SPMs' probabilities. The discriminative abilities and calibrations of this competing-risk nomogram were assessed by the area under the receiver-operating characteristic (ROC) curves (AUC) and calibration curves.

RESULTS

We identified 11,017 colorectal NENs' patients, and randomly divided them into training (n = 7711 patients) and validation (n = 3306 patients) cohorts. In the whole cohort, 12.4% patients (n = 1369) had developed SPMs during the maximum follow-up of approximately 19 years (median 8.9 years). Sex, age, race, primary tumor location, and chemotherapy were identified as risk factors for SPMs' occurrence in colorectal NENs' patients. Such factors were selected to develop a competing-risk nomogram and showed excellent predictive ability for SPMs' occurrence (the 3-, 5-, and 10-year AUC values were 0.631, 0.632, and 0.629 in the training cohort and 0.665, 0.639, 0.624 in the validation cohort, respectively).

CONCLUSIONS

This research identified risk factors for SPMs' occurrence in colorectal NENs' patients. Competing-risk nomogram was constructed and proved to have good performance.

Secondary Primary Cancer after Primary Gastric Cancer: Literature Review and Big Data Analysis Using the Health Insurance Review and Assessment Service (HIRA) Database of Republic of Korea

Advances in cancer screening and early detection, as well as improvements in surgical techniques and therapeutics, have contributed to decreasing gastric cancer mortality. The number of gastric cancer survivors continues to rise; however, long-term follow-up has revealed an increase in the risk of post-gastrectomy symptoms or other health problems, such as extra-gastric secondary primary cancer (SPC), in these survivors. Therefore, evidence-based screening for new primary cancer is needed in these populations; however, the incidence of SPC varies by country or continent and its characteristics have not been clearly reported. The characteristics of SPC are of increasing interest to both treatment providers and gastric cancer survivors; thus, this literature review explores not only the epidemiology and biology of SPC but also clinical and biological factors that influence its prognosis.

Genetic mutation and tumor microbiota determine heterogenicity of tumor immune signature: Evidence from gastric and colorectal synchronous cancers

Both colorectal and gastric cancer are lethal solid-tumor malignancies, leading to the majority of cancer-associated deaths worldwide. Although colorectal cancer (CRC) and gastric cancer (GC) share many similarities, the prognosis and drug response of CRC and GC are different. However, determinants for such differences have not been elucidated. To avoid genetic background variance, we performed multi-omics analysis, including single-cell RNA sequencing, whole-exome sequencing, and microbiome sequencing, to dissect the tumor immune signature of synchronous primary tumors of GC and CRC. We found that cellular components of juxta-tumoral sites were quite similar, while tumoral cellular components were specific to the tumoral sites. In addition, the mutational landscape and microbiome contributed to the distinct TME cellular components. Overall, we found that different prognoses and drug responses of GC and CRC were mainly due to the distinct TME determined by mutational landscape and microbiome components.

Epidemiological analysis of second primary malignant neoplasms in cancer survivors aged 85 years and older: a SEER data analysis (1975-2016)

Cancer burden in patients aged 85 years and older has rapidly increased accompanying the decrease in mortality, which is raising the concern of developing second primary malignant neoplasms (SPM). This study aimed to investigate the epidemiology of the SPM in this population in the US by using the surveillance, epidemiology, and end results database (1975-2016). The cumulative incidence of developing a SPM was calculated by the Fine and Gray model. Standardized incidence ratios (SIR) were calculated via Poisson regression. The relative post-SPM survival rate was calculated by the Kaplan-Meier method. Male patients with skin melanoma, kidney and renal pelvis and urinary bladder cancers had high cumulative incidences (15.32%, 13.55%, and 12.26%, respectively) and increased SIRs (1.47, 1.44, and 1.16, respectively) for developing SPMs. Female patients with skin melanoma and urinary bladder cancers had high cumulative incidences (10.18% and 7.87%, respectively) and increased SIRs (1.34 and 1.18, respectively). In general, the incidence of SPM cases increased over time. The median latency ranged from 17 to 37 months. A less than 50% of patients had 1-year post-SPM survival. In conclusion, some of these patients had an increased risk of the SPM, with poor survival.

Detection of secondary upper gastrointestinal tract cancer during follow‐up esophagogastroduodenoscopy after gastrectomy for gastric cancer

Aim

Esophagogastroduodenoscopy (EGD) may contribute to early detection of secondary cancer in the upper gastrointestinal tract although the clinical relevance of follow‐up after gastrectomy remains unclear. This study aimed to elucidate the effectiveness of follow‐up EGD by investigating the incidence of secondary cancer in any part of the upper gastrointestinal tract.

Methods

Data from 1438 patients who underwent curative partial gastrectomy for primary gastric cancer between 2008 and 2014 and follow‐up EGD at least once during a 5‐year follow‐up period were retrospectively reviewed. Incidence rates of remnant gastric cancer, laryngeal cancer, and esophageal cancer detected after follow‐up EGD were determined, and risk factors for secondary cancers were examined. The characteristics of clinicopathological diagnoses of secondary cancers were reviewed and compared according to the frequency of follow‐up EGD.

Results

The average annual frequency of EGD was 0.7, while the 5‐year cumulative incidence rates of remnant gastric cancer and secondary laryngeal and esophageal cancers were 2.9% and 1.3%, respectively. Risk factors for remnant gastric cancer included heavy smoking, proximal gastrectomy, and tumor size ≥ 30 mm. All secondary cancers were resectable upon diagnosis, with endoscopically resectable cancer accounting for 81.0% of cases. Our results found a significantly higher proportion of endoscopically resectable cancers during regular follow‐up than during infrequent follow‐up.

Conclusions

Follow‐up EGD can be a useful modality for detecting secondary upper gastrointestinal tract cancer, likely leading to curative treatment for secondary cancer. Focusing on patients presenting with risk factors may increase the value of follow‐up EGD after gastrectomy.

The Relationship between Diabetes Mellitus and Gastric Cancer and the Potential Benefits of Metformin: An Extensive Review of the Literature

The objective of this review is to summarize the findings of published research that investigated the relationship between diabetes mellitus and gastric cancer (GCa) and the potential benefits of metformin on GCa. Related literature has been extensively reviewed, and findings from studies investigating the relationship between diabetes mellitus and GCa suggest that hyperglycemia, hyperinsulinemia and insulin resistance are closely related to the development of GCa. Although not supported by all, most observational studies suggest an increased risk of GCa in patients with type 2 diabetes mellitus, especially in women and in Asian populations. Incidence of second primary malignancy diagnosed after GCa is significantly higher in diabetes patients. Diabetes patients with GCa may have more complications after gastrectomy or chemotherapy and they may have a poorer prognosis than patients with GCa but without diabetes mellitus. However, glycemic control may improve in the diabetes patients with GCa after receiving gastrectomy, especially after procedures that bypass the duodenum and proximal jejunum, such as Roux-en-Y gastric bypass or Billroth II reconstruction. The potential links between diabetes mellitus and GCa may involve the interactions with shared risk factors (e.g., obesity, hyperglycemia, hyperinsulinemia, insulin resistance, high salt intake, smoking, etc.), Helicobacter pylori (HP) infection, medications (e.g., insulin, metformin, statins, aspirin, proton pump inhibitors, antibiotics, etc.) and comorbidities (e.g., hypertension, dyslipidemia, vascular complications, heart failure, renal failure, etc.). With regards to the potential benefits of metformin on GCa, results of most observational studies suggest a reduced risk of GCa associated with metformin use in patients with T2DM, which can be supported by evidence derived from many in vitro and animal studies. Metformin use may also reduce the risk of HP infection, an important risk factor of GCa. In patients with GCa, metformin users may have improved survival and reduced recurrence. More studies are required to clarify the pathological subtypes/anatomical sites of GCa associated with type 2 diabetes mellitus or prevented by metformin, to confirm whether GCa risk can also be increased in patients with type 1 diabetes mellitus and to explore the possible role of gastric microbiota in the development of GCa.

The effect of a gastric second primary cancer on the survival of patients with a previous cancer history

Second primary cancers (SPCs) are an increasing concern among cancer survivors. In Northern Portugal, gastric cancer incidence is high, and alone corresponds to one in 10 SPCs diagnosed. Therefore, this study aims to estimate the contribution of gastric SPCs to the mortality of patients with a previous cancer. A population-based cohort of nongastric first primary cancer (FPC) patients from the North Region Cancer Registry of Portugal, diagnosed between 2000 and 2006, was followed for a gastric SPC until the end of 2012, and for death by any cause until the end of 2017. Patients with a gastric SPC (85 synchronous and 215 metachronous, diagnosed within one and >1 year after the FPC, respectively) were matched (1:3, by sex, five-year age group, year and site of FPC diagnosis) to those who did not develop a gastric SPC and were alive when the corresponding SPC was diagnosed. Significantly higher hazards for mortality [hazard ratio (95% confidence interval)] were observed among patients diagnosed with a synchronous [3.74 (2.69-5.21) in males and 3.36 (2.02-5.58) in females] or metachronous [6.93 (5.41-8.87) in males and 5.93 (4.04-8.72) in females] gastric SPC. The differences in the 10-year cumulative mortality between gastric SPC patients and those with no SPC were approximately 30% for synchronous and over 40% for metachronous gastric SPCs, corresponding to a 1.5- to 2-fold higher relative risk, respectively. In conclusion, cancer patients with a gastric SPC have a nearly two-fold higher risk of death over 10 years than those with a corresponding FPC only.

Second Primary Cancers After Gastric Cancer, and Gastric Cancer as Second Primary Cancer

Background

Second primary cancers (SPCs) are increasing, which may negatively influence patient survival. Gastric cancer (GC) has poor survival and when it is diagnosed as SPC it is often the cause of death. We wanted to analyze the risk of SPCs after GC and the risk of GC as SPC after any cancer. Such bidirectional analysis is important in relation to fatal cancers because SPCs may be under-reported in the short-term survival period.

Methods

Cancers were obtained from the Swedish Cancer Registry from years 1990 through 2015. Standardized incidence ratios (SIRs) were used to estimate bidirectional relative.

Results

We identified 23,137 GC patients who developed 1042 SPCs (4.5%); 2158 patients had GC as SPC. While the risk for three SPCs was increased after GC, seven first primary cancers were followed by an increased risk of GC as SPC, including esophageal, colorectal, bladder, squamous cell skin and breast cancers and non-Hodgkin lymphoma. Breast cancer, which was followed by a diagnosis of second GC, showed an excess of lobular histology.

Conclusion

Multiple primary cancers in the same individuals may signal genetic predisposition. Accordingly, the association of GC with breast cancer may be related to mutations in the CDH1 gene, and clustering of colorectal, small intestinal and bladder cancers could be related to Lynch syndrome. The third line of findings supports a contribution of immune dysfunction on the increased risk of GC as SPC after skin cancer and non-Hodgkin lymphoma. Early detection of GC in the risk groups could save lives.

Second primary malignancies in colorectal cancer patients

The prevalence of second primary malignancies (SPMs) in the western world is continually increasing with the risk of a new primary cancer in patients with previously diagnosed carcinoma at about 20%. The aim of this retrospective analysis is to identify SPMs in colorectal cancer patients in a single-institution cohort, describe the most frequent SPMs in colorectal cancer patients, and discover the time period to occurrence of second primary tumors. We identified 1174 patients diagnosed with colorectal cancer in the period 2003–2013, with follow-up till 31.12.2018, and median follow-up of 10.1 years, (median age 63 years, 724 men). A second primary neoplasm was diagnosed in 234 patients (19.9%). Older age patients, those with early-stage disease and those with no relapse have a higher risk of secondary cancer development. The median time from cancer diagnosis to development of CRC was 8.9 years for breast cancer and 3.4 years for prostate cancer. For the most common cancer diagnosis after primary CRC, the median time to development was 0–5.2 years, depending on the type of malignancy. Patients with a diagnosis of breast, prostate, or kidney cancer, or melanoma should be regularly screened for CRC. CRC patients should also be screened for additional CRC as well as cancers of the breast, prostate, kidney, and bladder. The screening of cancer patients for the most frequent malignancies along with systematic patient education in this field should be the standard of surveillance for colorectal cancer patients.

Curcumol improves cisplatin sensitivity of human gastric cancer cells through inhibiting PI3K/AKT pathway

BACKGROUND

Curcumol was presented to unleash antitumor effects in a variety of cancers, including gastric cancer. However, the relevance between curcumol and cisplatin resistance in gastric cancer still remains unclear. Therefore, the current research was performed to survey the role of curcumol in cisplatin sensitivity in gastric cancer.

METHODS

First, BGC-823 and BGC-823/DDP cells were incubated with cisplatin for 48 hr and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) analysis was applied to determine the inhibition rate of cell proliferation and the half-maximal inhibitory concentration (IC50 ) of cisplatin. In addition, BGC-823 and BGC-823/DDP cells were treated with curcumol for 48 hr followed with detection of cell viability and apoptosis using MTT and flow cytometry assay, respectively. Moreover, MTT analysis was applied to test the effects of curcumol on cisplatin sensitivity in gastric cancer cells. Lastly, Western blot assay and qRT-PCR analysis were utilized to check the functions of curcumol on PI3K/AKT pathway-related markers.

RESULTS

We found that BGC-823/DDP cells exhibited stronger resistance to cisplatin compared with BGC-823 cells. Furthermore, curcumol evidently reduced cell proliferation and facilitated cell apoptosis in BGC-823/DDP and BGC-823 cells. Moreover, results from MTT assay demonstrated that curcumol notably promoted the suppression effect of cisplatin and decreased the IC50 of cisplatin in BGC-823/DDP and BGC-823 cells. It was also presented that curcumol suppressed the PI3K/AKT pathway dose-dependently in BGC-823/DDP and BGC-823 cells.

CONCLUSION

The findings in the current research demonstrated that curcumol could promote the sensitivity of gastric cancer cells to cisplatin-based chemotherapies via inhibiting the phosphatidylinositol 3-kinase (PI3K)/Protein Kinase B (AKT) pathway.

Second primary malignancies among cancer patients

Background

Rate of second primary malignancies (SPM) is steadily increasing over the last decades. New therapies, early diagnostic markers, screening tests for a larger number of individuals contribute to the increase prevalence of SPM. In the current study, we try to described the demographic composition of SPM victims, distribution of primary sites, and the impact of related factors on prognosis.

Methods

We conducted a retrospective study identifying patients over the age of 18 who were diagnosed with SPM from the 16 most common cancer sites between 2000 and 2013 from Surveillance, Epidemiology, and End Results data. Cox proportional hazards regression was used to analyze the relationship between different factors associated to the prognosis of SPM. Standard incidence rate of multiple primary (MP-SIR) was also calculated.

Results

A total of 303,753 patients were diagnosis with SPM and 76,168 of whom (25.08%) were included in our analytic cohort. Patients with prostate cancer was vulnerable to SPM, accounting for 34.59%, and SPM was prone to occur in lung and bronchus, accounting for 24.90%. The heat map shows that esophagus cancer survivors have the highest risk of developing stomachache tumors (SIR =5.08). The result of Cox regression suggests that a history of liver was associated with the shortest survival time (HR =1.64, 95% CI, 1.54-1.75, P<0.001).

Conclusions

With the advancement of medical standards, the survival time of cancer patients is prolonged, but the occurrence of SPM is also increasing, and the prognosis is not optimistic. More attention needs to be invested in the prevention and treatment of SPM.

The impact of preoperative glycated hemoglobin levels on outcomes in oral squamous cell carcinoma

OBJECTIVES

This study aimed to investigate the association between preoperative glycated hemoglobin (HbA1c) levels and the treatment outcomes of oral cavity squamous cell carcinoma (OSCC).

METHODS

Three hundred and fifty-eight OSCC patients were consecutively enrolled between July 2004 and July 2016. Clinicopathological parameters and survival outcomes were analyzed following HbA1c stratification of 6.5% (HbA1c ≥ 6.5%: n = 74, 20.6%) and 7.0% (HbA1c ≥ 7.0%: n = 53, 14.8%).

RESULTS

Higher HbA1c levels were associated with elevated body mass index, lower albumin levels, wider surgical margins, and prolonged hospital stays (HbA1c 6.5%: p = .001, .048, .030, .009, respectively; HbA1c 7.0%: p = .092, .032, .009, .015, respectively). Survival rates stratified by HbA1c 6.5% were as follows: locoregional recurrence-free survival, p = .014; distant metastasis-free survival, p = .013; second primary cancer-free survival, p = .015; overall survival, p = .014; disease-specific survival, p = .002 and HbA1c 7.0%: locoregional recurrence-free survival, p = .013; distant metastasis-free survival, p = .013; second primary cancer-free survival, p = .014; overall survival, p = .015; disease-specific survival, p = .004. Multivariate analyses identified HbA1c as an independent prognostic factor for overall and disease-specific survival (HbA1c 6.5%: p = .014 and .002, respectively; HbA1c 7.0%: p = .036 and .013, respectively).

CONCLUSIONS

Oral squamous cell carcinoma patients with higher preoperative HbA1c levels had longer hospitalization and worse survival outcomes.

Laparoscopic radical resection of gastric cancer and metachronous colon cancer-a case report

Due to the favorable prognosis of gastric cancer (GC), the incidence of second primary cancer (SPC) accompanied with GC has increased. Here, we reported a case of a 69-year-old male patient with metachronous GC and colon cancer, who had undergone laparoscopic radical resection of distal GC 4 years ago. During this hospitalization, the patient underwent laparoscopic radical resection of left hemicolectomy for metachronous colon cancer. Few literatures have reported that patients with metachronous GC and colon cancer can receive laparoscopic surgery successfully. The patient recovered well and was discharged on day 10 post-operation. The pathologic specimen was identified as metachronous colon cancer. We concluded that GC patients need regular standard follow-up programs after undergoing operations. For multiple primary cancers (MPCs), treatments need to be individualized and comprehensive. Laparoscopic surgery is recommended as an appropriate option.

[Second Primary Cancer after Treating Gastrointestinal Cancer]

Advances in diagnosis and therapeutic technologies have brought increased life expectancy for most cancers, but paradoxically it also has increased the risk of second primary malignancies. Cancer survivors have a higher risk of developing cancer than the general population. This suggests that more studies are needed to develop screen and management programs for cancer survivors, especially patients with gastrointestinal cancers, which are the most common cancers in Korea.

Second primary cancers and survival in patients with gastric cancer: association with prediagnosis lifestyles

To quantify the association between prediagnosis lifestyles with the risk of second primary cancers (SPCs) and survival of patients with gastric first primary cancer (FPC). We recruited 574 gastric patients from two major public hospitals in North Portugal (2001-2006). Smoking, alcohol and dietary habits in the year before FPC diagnosis were evaluated. Patients were followed up to 31 December 2011 for an SPC and to 31 May 2017 for vital status. Cox proportional hazards regression was used to estimate adjusted hazard ratios for incidence of an SPC or death. During follow-up, SPCs were diagnosed in five women and 23 men, and 409 patients died, corresponding to an estimated 10-year cumulative incidence of 5.2% for SPC and an estimated 15-year cumulative mortality of 72.1%. A significantly higher hazard ratio (95% confidence interval) for SPCs was observed in patients reporting a higher consumption of red and processed meat versus the lowest third (4.49: 1.31-15.37), and for mortality in those with heavy alcohol intake versus never drinkers (1.73: 1.00-2.99) and excess weight versus normal weight (1.31: 1.04-1.65); no other significant associations were observed according to prediagnosis lifestyle. Prediagnosis lifestyles may affect the occurrence of an SPC and survival among gastric FPC survivors in the long term.

Second primary cancers in patients with oral cavity cancer included in the Korea Central Cancer Registry

OBJECTIVES

The improved survival of patients with oral cavity cancer (OCC) has generated interest in factors affecting survivorship, particularly among second primary cancer (SPC) patients. This study aimed to assess the incidence, patterns, and risk factors for SPC after OCC treatment in the Korean population.

MATERIALS AND METHODS

Data from 15,261 patients with OCC (ICD-O: C01-C06) identified between 1993 and 2014 were extracted from the Korean Central Cancer Registry. The standardized incidence ratio (SIR) for SPC after index OCC was calculated, and Poisson regression analysis was performed to evaluate the risk factors for SPC among survivors.

RESULTS

The overall SIR for SPC among OCC survivors was 1.47 (95% confidence interval [CI] 1.39-1.56). SIR differed by sex (male: 1.51 vs. female: 1.37), age at diagnosis (<45 years: 2.47 vs. 45-64 years: 1.68 vs. ≥ 65 years: 1.10), index OCC subsite (floor of mouth: 1.95 vs. gum: 1.30), follow-up duration (6-23 months: 1.64 vs. 24-59 months: 1.51 vs. 60-119 months: 1.48 vs. ≥ 120 months: 1.24), histological OCC type (salivary gland malignancy: 1.77 vs. squamous cell carcinoma: 1.44 vs. others: 1.47), and radiation history (any: 1.94 vs. no radiation: 1.37). The risk factors for SPC development among OCC survivors included younger age at diagnosis and history of radiation therapy.

CONCLUSION

OCC survivors have significantly increased risks of SPCs, exhibiting distinctive site distributions and chronological patterns. These patients would benefit from an SPC surveillance protocol.

The contribution of second primary cancers to the mortality of patients with a gastric first primary cancer

OBJECTIVES

Gastric first primary cancers (FPCs) have an increased risk of developing second primary cancers (SPCs). However, their effect on mortality remains poorly understood. Thus, we aimed to estimate the contribution of SPCs to the mortality of gastric FPCs.

PATIENTS AND METHODS

A population-based cohort of gastric FPCs diagnosed in 2000-2006 was followed for SPCs (31 December 2012) and vital status (31 December 2017). SPCs (138 synchronous and 205 metachronous, ≤1 and >1 year after the FPC, respectively) were matched (1 : 3, by sex, 5-year age group, and year of FPC diagnosis) with those without an SPC and alive when the corresponding SPC was diagnosed.

RESULTS

In synchronous SPCs, the hazard ratio (95% confidence interval) for death was 1.07 (0.81-1.40) in males and 0.86 (0.58-1.28) in females; the corresponding estimates for metachronous SPCs were 1.89 (1.49-2.41) and 2.08 (1.42-3.05). In synchronous SPCs, the 10-year cumulative mortality was similar to that of FPCs only; the estimates were higher in lung SPCs. The 10-year cumulative mortality was 75.5% in males and 65.5% in females with metachronous SPCs, which is more than 20% higher than for FPCs only.

CONCLUSION

Among patients with gastric FPCs who survive long enough for metachronous SPCs, the latter substantially increases mortality over 10 years, whereas the effect of synchronous SPCs is generally smaller.

Risk of second primary cancers among patients with a first primary gastric cancer: A population-based study in North Portugal

BACKGROUND

The growing number of incident cases of gastric cancer along with improved survival result in a rising population of survivors at risk of second primary cancers (SPC). We estimated the cumulative incidence of metachronous (diagnosed >2months after first primary cancer [FPC]) SPC in gastric FPC patients and compared the incidence of metachronous SPC with that expected in the general population.

METHODS

A cohort of gastric FPC patients from the North Region Cancer Registry of Portugal, diagnosed in 2000-2006 (n=7427) was followed to 31 December 2010 for synchronous and metachronous SPCs. Cumulative incidence of metachronous SPCs taking into account death as a competing event and standardized incidence ratios (SIR) of metachronous SPCs were estimated.

RESULTS

Overall, 331 (4.5%) patients developed an SPC (26.9% synchronous and 73.1% metachronous). Over half of the SPCs occurred in digestive organs. Among men, the most frequent were colon, prostate, and trachea, bronchus and lung; in women, colon, breast and thyroid were the most common. The 10-year cumulative incidence of metachronous SPC for males was 5.7% and for females 3.5%. The SIR for all cancers was 1.30 in males and 1.20 in females. Among both sexes, significantly higher SIRs were observed for cancers of the oesophagus (males: 4.99; females: 8.03), small intestine (males: 11.04; females: 13.09) and colon (males: 2.42; females: 2.58).

CONCLUSIONS

Patients with a gastric FPC were found to be at increased risk of developing SPC, mainly in digestive organs, when compared to the general population. Close surveillance of these patients may allow early detection of SPC.