Prediction of Conditional Probability of Survival After Surgery for Gastric Cancer: A Study Based on Eastern and Western Large Data Sets

Sequential changes in conditional survival of patients undergoing curative gastrectomy for gastric cancer

BACKGROUND

Long-term data on the prognosis of patients who survived >5 years after gastrectomy for gastric cancer (GC) remain scarce. This study aimed to investigate sequential changes in conditional survival (CS) in patients with stage I-III GC who underwent R0 gastrectomy.

METHODS

Of 1129 patients with stage I to III GC who underwent R0 gastrectomy, the causes of death were assessed, and sequential changes in conditional overall survival (cOS), conditional disease-specific survival (cDSS), and conditional non-disease-specific survival (cNDSS) were calculated and compared. In a subgroup of 709 patients who survived >5 years, the associations between cOS, cDSS, cNDSS, and clinicopathologic factors were analyzed.

RESULTS

Over a median follow-up of 63 months, 203 patients (18.0%) died of GC, and 132 patients (11.7%) died of non-GC causes. The 5-year cDSS consistently increased over 10 years after gastrectomy for stage II and III GC. The cDSS and cNDSS intersected at 7 years after gastrectomy for stage II GC, whereas these measures crossed at 8 years after gastrectomy for stage III GC. In the 709 5-year survivors, multivariate analysis identified disease stage as being significantly associated with cOS and cDSS. Moreover, age ≥ 80 years, male sex, and preoperative comorbidities were associated with lower cNDSS.

CONCLUSION

Surveillance for GC relapse was crucial during the first 7 and 8 years after gastrectomy for stages II and III, respectively. Conversely, surveillance for second primary cancers and benign diseases became relatively more important 0, 7, and 8 years after gastrectomy for stages I, II, and III, respectively. In 5-year survivors, age ≥ 80 years, male sex, and preoperative comorbidities were associated with mortality unrelated to GC.

Prognostic Factors of Long-Term Survival and Conditional Survival Analysis in MPM Patients Treated with CRS+HIPEC: A Retrospective Study of Two Centers

OBJECTIVES

This study was designed to explore the survival benefit factors of malignant peritoneal mesothelioma (MPM) patients after cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) and to make dynamic survival prediction by conditional survival (CS).

METHODS

Data of 212 patients with MPM who underwent CRS+HIPEC were retrospectively analyzed. Patients were divided into long-term survival (LTS) group (≥48.0 months) and short-term survival (STS) group (≤16.0 months) according to OS. Conditional survival is the probability of surviving y years after already survived for x years. Univariate and multivariate analyses were performed to explore the favorable factors of LTS. Conditional survival and Kaplan-Meier were applied to assess the postoperative survival probability.

RESULTS

Ninety patients were enrolled: 53 (58.9%) were LTS, and 37 (41.1%) were STS. Univariate analysis revealed 14 meaningful factors (P < 0.05): age, surgery history, Karnofsky performance status, pathological types, tumor vascular emboli, lymphatic metastasis, Ki-67 index, preoperative CA125 level, peritoneal cancer index (PCI), completeness of cytoreduction, bleeding, red blood cell (RBC) transfusion, ascites, and severe adverse events (SAEs). Multivariate analysis identified that PCI ≤ 20, less RBC transfusion and no SAEs were independent prognostic factors for LTS. Five-year CS increased from 27% at 0 years to 84% at 4 years with the increasing number of survival years. The survival curve flattens at postoperative 5 years.

CONCLUSIONS

The key factors in CRS+HIPEC for MPM patients to achieve LTS are lower tumor burden, less intraoperative RBC transfusion, and prevention of SAEs. Malignant peritoneal mesothelioma patients demonstrated a substantial increase in CS over time. Some patients may achieve clinical cure 5 years after surgery.

Prognostic factors for relapse-free 5-year survivors after gastrectomy for gastric cancer

BACKGROUND

Few studies have examined the prognosis of long-term survivors with gastric cancer (GC) after gastrectomy. This study aimed to identify the prognostic factors for 5-year recurrence-free survivors after gastrectomy for GC.

METHODS

A total of 721 patients with pathologic stage Ⅰ to Ⅲ GC who underwent gastrectomy between 2005 and 2018 and survived for 5 years without recurrence were enrolled. Conditional overall survival (cOS), conditional disease-specific survival (cDSS), and conditional non-disease-specific survival (cNDSS) of 5-year recurrence-free survivors were calculated. The association between cOS, cDSS, and cNDSS and clinicopathologic factors was evaluated using univariate and multivariate analyses.

RESULTS

The mean age of the patients was 70.5 ± 10.1 years, 68.5% of the patients were male, and 491, 128, and 102 had stage Ⅰ, Ⅱ, and Ⅲ GC, respectively. Of note, 17 patients relapsed, and 65 patients died (disease-specific, non-disease-specific, and unknown: 12, 45, and 6, respectively) during a median follow-up of 36 months. The 5-year cOS, cDSS, and cNDSS rates were 90.3%, 97.3%, and 93.3%, respectively. Multivariate analysis showed that age of ≥80 years and neutrophil-to-lymphocyte ratio (NLR) of ≥2.7 were significantly associated with poorer cOS. Stage Ⅲ GC was associated with decreased cDSS, and age of ≥80 years, NLR of ≥2.7, and mean corpuscular volume (MCV) of ≥93.4 fL were associated with lower cNDSS.

CONCLUSION

Age of ≥80 years, stage Ⅲ GC, NLR of ≥2.7, and MCV of ≥93.4 fL were unfavorable prognostic factors for 5-year recurrence-free survivors after gastrectomy for GC. Long-term surveillance after gastrectomy could be tailored based on these factors.

miR-325-3p Reduces Proliferation and Promotes Apoptosis of Gastric Cancer Cells by Inhibiting Human Antigen R

Human antigen R (HuR), also known as ELAVL1, is a widely expressed RNA-binding protein (RBP) that has a significant impact on the development and advancement of tumors. Our previous study found that 5-fluorouracil (5-FU) may impede the proliferation and increase apoptosis in gastric cancer cells by reducing the nucleocytoplasmic shuttling of HuR. However, how posttranscriptional regulation influences HuR functions in gastric cancer remains to be elucidated. Here, we demonstrated that miR-325-3p has the potential to regulate the expression level of HuR by directly binding to its 3'UTR, which in turn led to a significant reduction in proliferation and an increase in apoptosis in gastric cancer cells. In addition, xenograft experiment showed that knockdown of HuR or overexpression of miR-325-3p group exhibited smaller tumor sizes after transplant of gastric cancer cells into zebrafish larvae. Thus, our findings offer new insights into the pathogenesis of gastric cancer and may potentially assist in identifying novel targets for drug therapy.

Conditional Survival After Hepatectomy for Colorectal Liver Metastasis: Results from the Colorectal Liver Operative Metastasis International Collaborative (COLOMIC)

INTRODUCTION

Complete resection of colorectal liver metastasis (CLM) improves long-term survival in colorectal cancer. However, there is limited recent data on conditional survival (CS) as postoperative survival milestones are achieved post-hepatectomy.

METHODS

A retrospective analysis was performed on the penta-institutional Colorectal Liver Operative Metastasis International Collaborative (COLOMIC), with 906 consecutive CLM hepatectomy cases. CS was calculated using Bayes' theorem and Kaplan-Meier analysis. Additional CS analyses were performed on additional clinicopathologic risk factors, including colon cancer laterality, KRAS mutation status, and extrahepatic disease.

RESULTS

The 5-year CS was 40.6%, 45.3%, 52.8%, and 65.3% at 0, 1, 2, and 3 years postoperatively, with significant improvements each year (p < 0.005). CS was not significantly different between right-sided and left-sided colorectal cancers by 3 years postoperatively. Patients with KRAS mutations had worse CS at all timepoints (p < 0.001). Extrahepatic disease was a poor prognostic factor for OS and CS (p < 0.001). However, CS for patients with KRAS mutations or extrahepatic disease improved significantly as 2-year, postoperative survival was achieved (p < 0.05).

CONCLUSIONS

Five-year CS after hepatectomy for CLM improved with each passing year of survival postoperatively. Although extrahepatic disease and KRAS mutations are poor prognostic factors for OS, these populations still had improved CS after 2 years postoperatively.

Long-Term Survival in Patients Treated with Cytoreduction and Heated Intraperitoneal Chemotherapy for Peritoneal Mesothelioma at a Single High-Volume Center

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare diagnosis with a dismal prognosis if untreated. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is shown to significantly improve survival. Our institution is uniquely positioned to report long-term outcomes in MPM with CRS-HIPEC, due to our robust peritoneal surface disease program existing over the past three decades.

METHODS

Our prospectively maintained, single-institution database of CRS-HIPEC cases was reviewed, identifying 111 consecutive patients with MPM over 28 years (1993-2021). Prognostic, operative, and pathologic factors were reviewed. Overall survival (OS) and conditional survival (CS) analyses were performed.

RESULTS

The average age was 55.1 years; 58.6% of patients were male; 17 of 111 patients (15.3%) had a second CRS-HIPEC. At first CRS-HIPEC, the average PCI score was 18.7, and the perfusate drugs were platinum-based (72.1%) and mitomycin C (27.9%). The resection status at first CRS-HIPEC was R2a (46.4%), followed by R0-1 (29.1%), and R2b-c (24.5%). Median OS was 3.3 years for the entire cohort, with 75th and 25th percentiles at 10.7 months and 10.6 years. Median CS was improved if patients survived to the 1-year postoperative mark (4.9 years, p < 0.01) and trended toward further improvement with each passing year. If 3-year postoperative survival was achieved, the median CS improved to 6.1 years.

CONCLUSIONS

This represents one of the largest and lengthiest, single-center, longitudinal, case series of peritoneal mesothelioma treated with CRS-HIPEC. The OS suggests efficacy for CRS-HIPEC for MPM. Long-term survival improves significantly after patients achieve the 1-year, postoperative mark.

Conditional survival nomogram predicting real-time prognosis of locally advanced breast cancer: Analysis of population-based cohort with external validation

Background

Locally advanced breast cancer (LABC) is generally considered to have a relatively poor prognosis. However, with years of follow-up, what is its real-time survival and how to dynamically estimate an individualized prognosis? This study aimed to determine the conditional survival (CS) of LABC and develop a CS-nomogram to estimate overall survival (OS) in real-time.

Methods

LABC patients were recruited from the Surveillance, Epidemiology, and End Results (SEER) database (training and validation groups, n = 32,493) and our institution (testing group, n = 119). The Kaplan-Meier method estimated OS and calculated the CS at year (x+y) after giving x years of survival according to the formula CS(y|x) = OS(y+x)/OS(x). y represented the number of years of continued survival under the condition that the patient was determined to have survived for x years. Cox regression, best subset regression, and the least absolute shrinkage and selection operator (LASSO) regression were used to screen predictors, respectively, to determine the best model to develop the CS-nomogram and its network version. Risk stratification was constructed based on this model.

Results

CS analysis revealed a dynamic improvement in survival occurred with increasing follow-up time (7 year survival was adjusted from 63.0% at the time of initial diagnosis to 66.4, 72.0, 77.7, 83.5, 89.0, and 94.7% year by year [after surviving for 1-6 years, respectively]). In addition, this improvement was non-linear, with a relatively slow increase in the second year after diagnosis. The predictors identified were age, T and N status, grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER 2), surgery, radiotherapy and chemotherapy. A CS-nomogram developed by these predictors and the CS formula was used to predict OS in real-time. The model's concordance indexes (C-indexes) in the training, validation and testing groups were 0.761, 0.768 and 0.810, which were well-calibrated according to the reality. In addition, the web version was easy to use and risk stratification facilitated the identification of high-risk patients.

Conclusions

The real-time prognosis of LABC improves dynamically and non-linearly over time, and the novel CS-nomogram can provide real-time and personalized prognostic information with satisfactory clinical utility.

Dynamic Prediction of Survival after Curative Resection of Gastric Adenocarcinoma: A landmarking-based analysis

BACKGROUND

Accurate estimation of survival and recurrence are important to inform decisions regarding therapy and surveillance. We sought to design and validate a dynamic prognostic model for patients undergoing resection for gastric adenocarcinoma.

METHODS

Patients who underwent curative-intent surgery for gastric adenocarcinoma between 2000 and 2020 were identified using a multi-institutional database. Landmark analysis was used to create dynamic OS and DFS prediction models. Model performance was internally cross-validated via bootstrap resampling.

RESULTS

Among 895 patients, 507 (57.2%) patients underwent partial gastrectomy (n = 507, 57.2%) while 380 (42.8%) had total gastrectomy. Median tumor size was 40 mm (IQR: 25-65), most tumors were located in the antrum (n = 344, 39.5%) and infiltrated the subserosa (T3 tumors: n = 283, 31.9%) or serosa (T4 tumors: n = 253, 28.5%); lymph node metastasis occurred in 528 (59.1%) patients. Median OS and DFS were 17.5 (IQR: 7.5-42.8) and 14.3 months (IQR: 6.5-39.9), respectively. The impact of age, sex, preoperative comorbidities, tumor size and location, extent of lymphadenectomy and total number of lymph nodes examined, Lauren class, T and N category, postoperative complications, and tumor recurrence varied over time (all p < 0.05). An online tool to predict dynamic OS and DFS based on patient survival relative to time survived was developed and made available for clinical use. Discrimination ability of OS and DFS was excellent (C-index: 0.84 and 0.86, respectively) and calibration plots revealed good prediction.

CONCLUSIONS

An online dynamic prognostic tool was developed and validated to predict OS and DFS following resection of gastric adenocarcinoma. Landmark analysis to predict long-term outcomes based on follow-up time may be helpful to surgeons and patients.

Individualized conditional survival nomograms for patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy and radical surgery

BACKGROUND

Conditional survival (CS) considers the time already survived after surgery when estimating the survival probability, which may provide further useful prognostic information.

OBJECTIVE

To evaluate CS in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT) and to create CS nomograms predicting the conditional probability of survival after proctectomy.

METHODS

Consecutive patients with LARC who received nCRT followed by radical resection between 2011 and 2016 were identified. CS was defined as the probability of surviving y years after already surviving for x years. The formula used for CS was CS(x|y) = S(x + y)/S(x), where S(x) represents the survival at x years. Nomograms were constructed to predict the 5-year conditional overall survival (cOS) and conditional recurrence-free survival (cRFS).

RESULTS

A total of 785 patients were included. The median follow-up time was 65.5 months. The probability of achieving 5-year survival after surgery for cancer increases with additional survival time. Maximum tumor diameter, distance from the anal verge, preoperative CA19-9 level, ypTNM stage and perineural invasion were independent predictors of OS, while maximum tumor diameter, distance from the anal verge, ypTNM stage and perineural invasion were independent risk factors for RFS. The nomograms predicted 5-year cOS and cRFS using these predictors and the time already survived. The online calculator can be accessed at http://www.rectalcancer.top/webcalculator.

CONCLUSION

The proposed nomograms predict survival in patients after surgery, taking the time already survived into account.

Establishment and Verification of a Nomogram for Predicting Survival in Patients with Small Intestinal Gastrointestinal Stromal Tumors

BACKGROUND

This study aimed to develop and validate nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) in small intestinal gastrointestinal stromal tumors (SI GISTs).

METHODS

Patients diagnosed with SI GISTs were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database and further randomly divided into training and validating cohorts. Univariate and multivariate Cox analyses were conducted in the training set to determine independent prognostic factors to build nomograms for predicting 3- and 5-year OS and CSS. The performance of the nomograms was assessed by using the concordance index (C-index), calibration plot, and the area under the receiver operating characteristic curve (AUC).

RESULTS

Data of a total of 776 patients with SI GISTs were retrospectively collected from the SEER database. The OS nomogram was constructed based on age, surgery, imatinib treatment, and American Joint Committee for Cancer (AJCC) stage, while the CSS nomogram incorporated age, surgery, tumor grade, and AJCC stage. In the training set, the C-index for the OS nomogram was 0.773 (95% confidence interval [95% CI]: 0.722-0.824) and for the CSS nomogram 0.806 (95% CI: 0.757-0.855). In the internal validation cohort, the C-index for the OS nomogram was 0.741, while for the CSS nomogram, it was 0.819. Well-corresponded calibration plots both in OS and CSS nomogram models were noticed. The comparisons of AUC values showed that the established nomograms exhibited superior discrimination power than the 7th Tumor-Node-Metastasis staging system.

CONCLUSION

Our nomogram can effectively predict 3- and 5-year OS and CSS in patients with SI GISTs, and its use can help improve the accuracy of personalized survival prediction and facilitate to provide constructive therapeutic suggestions.

A Nomogram for Predicting Cancer-Specific Survival of Patients with Gastrointestinal Stromal Tumors

Background

The aim of this study was to construct a nomogram to predict the prognosis of patients with gastrointestinal stromal tumor (GIST).

Material/Methods

We enrolled 4086 GIST patients listed in the SEER database from 1998 to 2015. They were separated to 2 groups: an experimental group (n=2862) and a verification group (n=1224). A nomogram was constructed by using statistically significant prognostic factors.

Result

A nomogram that included age, sex, marital status, tumor location, grade, SEER stage, tumor size, and surgical management was developed. It can be used to predict overall survival (OS), while adding AJCC 7^th TNM stage can predict cancer-specific survival (CSS). The C-index used to forecast OS and CSS nomograms was 0.778 (95% CI, 0.76–0.79) and 0.818 (95% CI, 0.80–0.84), respectively.

Conclusions

The nomogram can effectively predict 3- and 5-year CSS in patients with GIST, and its use can improve clinical practice.

A Modified ypTNM Staging System-Development and External Validation of a Nomogram Predicting the Overall Survival of Gastric Cancer Patients Received Neoadjuvant Chemotherapy

Purpose

Neoadjuvant chemotherapy is now widely used in gastric cancer patients. However, the current 8th ypTNM staging system is developed based on patients with less extensive lymph node dissection and the predictive value is relatively limited. In this study, we aim to develop and validate a nomogram that predicts overall survival in gastric cancer patients received neoadjuvant chemotherapy.

Patients and Methods

From January, 2007 to December, 2014, 471 patients receiving neoadjuvant chemotherapy at our center were enrolled in the study. Based on the Cox proportional hazard model, a nomogram was developed from them and then an external validation was conducted on a cohort of 239 patients from another cancer center.

Results

The overall survival (OS) rates of 1 year and 3 years were 90.0% and 64.1%, respectively. Body mass index category, tumor location, T stage and N stage were independent prognostic factors for the survival outcome. The C-index of the model was 0.74 in the development cohort and 0.69 in the validation cohort. Our nomogram also showed good calibration in both cohorts.

Conclusion

We developed and validated a nomogram to predict the 1- and 3-year OS of patients who received neoadjuvant chemotherapy and radical gastrectomy with D2 lymph node dissection. This nomogram predicts survival more accurately than the AJCC TNM staging system, which is the current golden standard.

Conditional Survival After Resection for Pancreatic Cancer: A Population-Based Study and Prediction Model

Background

Conditional survival is the survival probability after already surviving a predefined time period. This may be informative during follow-up, especially when adjusted for tumor characteristics. Such prediction models for patients with resected pancreatic cancer are lacking and therefore conditional survival was assessed and a nomogram predicting 5-year survival at a predefined period after resection of pancreatic cancer was developed.

Methods

This population-based study included patients with resected pancreatic ductal adenocarcinoma from the Netherlands Cancer Registry (2005–2016). Conditional survival was calculated as the median, and the probability of surviving up to 8 years in patients who already survived 0–5 years after resection was calculated using the Kaplan–Meier method. A prediction model was constructed.

Results

Overall, 3082 patients were included, with a median age of 67 years. Median overall survival was 18 months (95% confidence interval 17–18 months), with a 5-year survival of 15%. The 1-year conditional survival (i.e. probability of surviving the next year) increased from 55 to 74 to 86% at 1, 3, and 5 years after surgery, respectively, while the median overall survival increased from 15 to 40 to 64 months at 1, 3, and 5 years after surgery, respectively. The prediction model demonstrated that the probability of achieving 5-year survival at 1 year after surgery varied from 1 to 58% depending on patient and tumor characteristics.

Conclusions

This population-based study showed that 1-year conditional survival was 55% 1 year after resection and 74% 3 years after resection in patients with pancreatic cancer. The prediction model is available via www.pancreascalculator.com to inform patients and caregivers.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08235-w) contains supplementary material, which is available to authorized users.

Conditional survival after neoadjuvant chemoradiotherapy and surgery for oesophageal cancer

Background

Conditional survival accounts for the time already survived after surgery and may be of additional informative value. The aim was to assess conditional survival in patients with oesophageal cancer and to create a nomogram predicting the conditional probability of survival after oesophagectomy.

Methods

This retrospective study included consecutive patients with oesophageal cancer who received neoadjuvant chemoradiation followed by oesophagectomy between January 2004 and 2019. Conditional survival was defined as the probability of surviving y years after already surviving for x years. The formula used for conditional survival (CS) was: CS_(x|y) = S_(x + y)/S_(x), where S_(x) represents overall survival at x years. Cox proportional hazards models were used to evaluate predictors of overall survival. A nomogram was constructed to predict 5‐year survival directly after surgery and given survival for 1, 2, 3 and 4 years after surgery.

Results

Some 660 patients were included. Median overall survival was 44·4 (95 per cent c.i. 37·0 to 51·8) months. The probability of achieving 5‐year overall survival after resection increased from 45 per cent directly after surgery to 54, 65, 79 and 88 per cent given 1, 2, 3 and 4 years already survived respectively. Cardiac co‐morbidity, cN category, ypT category, ypN category, chyle leakage and pulmonary complications were independent predictors of survival. The nomogram predicted 5‐year survival using these predictors and number of years already survived.

Conclusion

The probability of achieving 5‐year overall survival after oesophagectomy for cancer increases with each additional year survived. The proposed nomogram predicts survival in patients after oesophagectomy, taking the years already survived into account.

Nomogram for predicting the survival of gastric adenocarcinoma patients who receive surgery and chemotherapy

BACKGROUND

Surgery is the only way to cure gastric adenocarcinoma (GAC), and chemotherapy is the basic adjuvant management for GAC. A significant prognostic nomogram for predicting the respective disease-specific survival (DSS) rates of GAC patients who receive surgery and chemotherapy has not been established.

OBJECTIVE

We were planning to establish a survival nomogram model for GAC patients who receive surgery and chemotherapy.

METHODS

We identified 5764 GAC patients who had received surgery and chemotherapy from the record of Surveillance, Epidemiology, and End Results (SEER) database. About 70% (n = 4034) of the chosen GAC patients were randomly assigned to the training set, and the rest of the included ones (n = 1729) were assigned to the external validation set. A prognostic nomogram was constructed by the training set and the predictive accuracy of it was validated by the validation set.

RESULTS

Based on the outcome of a multivariate analysis of candidate factors, a nomogram was developed that encompassed age at diagnosis, number of regional lymph nodes examined after surgery, number of positive regional lymph nodes, sex, race, grade, derived AJCC stage, summary stage, and radiotherapy status. The C-index (Harrell's concordance index) of the nomogram model was some larger than that of the traditional seventh AJCC staging system (0.707 vs 0.661). Calibration plots of the constructed nomogram displayed that the probability of DSS commendably accord with the survival rate. Integrated discrimination improvement (IDI) revealed obvious increase and categorical net reclassification improvement (NRI) showed visible enhancement. IDI for 3-, 5- and 10- year DSS were 0.058, 0.059 and 0.058, respectively (P > 0.05), and NRI for 3-, 5- and 10- year DSS were 0.380 (95% CI = 0.316-0.470), 0.407 (95% CI = 0.350-0.505), and 0.413 (95% CI = 0.336-0.519), respectively. Decision curve analysis (DCA) proved that the constructed nomogram was preferable to the AJCC staging system.

CONCLUSION

The constructed nomogram supplies more credible DSS predictions for GAC patients who receive surgery and chemotherapy in the general population. According to validation, the new nomogram will be beneficial in facilitating individualized survival predictions and useful when performing clinical decision-making for GAC patients who receive surgery and chemotherapy.

Prognosis of Young Survivors of Gastric Cancer in China and the U.S.: Determining Long-Term Outcomes Based on Conditional Survival

BACKGROUND

Young survivors of gastric cancer (GC) have better prognoses than elderly patients, yet their disease-specific survival (DSS) has received little attention.

PATIENTS AND METHODS

Data on young patients (aged ≤40 years) with GC undergoing resections at three Chinese institutions (n = 542) and from the SEER database (n = 533) were retrospectively analyzed. Three-year conditional disease-specific survival (CS3) was assessed. The effects of well-known prognostic factors over time were analyzed by time-dependent Cox regression.

RESULTS

Overall, young Chinese patients with GC had a better 5-year DSS than U.S. patients (62.8% vs. 54.1%; p < .05). The disease-specific mortality likelihood of the entire cohort was not constant over time, with most deaths occurring during the first 3 years after surgery but peaking at 1 and 2 years in China and the U.S., respectively. Based on 5-year survivorship, the CS3 rates of both groups were similar (90.9% [U.S.] vs. 91.5% [China]; p > .05). Cox regression showed that for Chinese patients, site, size, T stage, and N stage were independent prognostic factors at baseline (p < .05). For U.S. patients, grade, T stage. and N stage significantly affected DSS at baseline (p < .05). In both groups, only T stage continuously affected DSS within 3 years after gastrectomy. However, for both groups, the initial well-known prognostic factors lost prognostic significance after 5 years of survival (all p > .05). Although the 5-year DSS rates of young Chinese patients with T3 and T4a disease were significantly better than those of young U.S. patients, in each T stage, the CS3 of both regions trended toward consistency over time.

CONCLUSION

For young patients with GC, the factors that predict survival at baseline vary over time. Although the initial 5-year DSS is heterogeneous, insight into conditional survival will help clinicians evaluate the long-term prognoses of survivors while ignoring population differences.

IMPLICATIONS FOR PRACTICE

With the increasing number of young survivors of gastric cancer (GC), it is essential for clinicians to understand the dynamic prognosis of these patients. Based on large data sets from China and the U.S., this study found that the prognostic factors that predict survival for young patients with GC at baseline vary over time. Although the initial 5-year disease-specific survival is heterogeneous, insight into conditional survival will help clinicians evaluate the long-term prognoses of survivors while ignoring population differences. This knowledge may be more effective in helping young patients with GC to manage future uncertainties, especially when they need to make important life plans.