following thyroid cancer , gastric cancer ( gc ) is the second most common cancer in korea . recently , as the korean society is aging , there has been an increasing number of elderly patients diagnosed with gc . despite this , there is little data available on the clinicopathological characteristics of gc in elderly patients , particularly in those who are very elderly . in korea , the life expectancy is more than 80 years and the most common cause of death is cancer . according to the statistics released by statistics korea , approximately 12% of cancer - related deaths although the 5-year survival rate of gc has been increasing over the past two decades due to early detection by screening endoscopy , little is known about gc screening in the very elderly . the safety of endoscopic treatment is comparable to surgery in elderly patients [ 4 - 8 ] . endoscopic resections ( ers ) are also performed on elderly patients with comorbid heart and lung diseases . therefore , the strategy of gc treatment varies in elderly patients with age - associated comorbidities . age is a clinically important factor for determining the treatment modality , and clinicians are often cautious when managing elderly patients with gc because of their age - related performance status [ 11 - 13 ] . this study investigated the clinicopathological characteristics of gc in extremely old ( over 85 years ) patients who received treatment or conservative observations . from june 1998 to july 2014 , a total of 358 patients over 85 years old were diagnosed with gc at severance hospital ( seoul , korea ) . for the present analysis , the following patients were excluded ( 1 ) those who had no subsequent follow - up visits after diagnosis , ( 2 ) those who had a significant comorbidity that could affect the mortality , and ( 3 ) those who had been treated at another hospital during the follow - up period . the patients were evaluated in terms of their general information , such as age , sex , and treatment method . the variables investigated also included the macroscopic classification , histological classification , comorbidity , postoperative mortality , and clinical outcome . as categorized by the treatment modality for gc , 81 patients underwent treatment ( treatment group ) , such as an endoscopic resection , surgery , chemotherapy , or radiotherapy , and 89 patients received conservative observation ( conservative group ) . therefore , the patients were divided roughly into two groups : those with macroscopically early gcs ( cancer confined to the mucosa or submucosa ) and those with macroscopically advanced gc ( cancer with invasion extending through the muscularis propria ) . the institutional review board ( irb ) of severance hospital approved this study ( irb approval number : 4 - 2014 - 0464 ) . the chi - square test and fisher exact test were used to compare the clinicopathological characteristics between the treatment - modality groups . follow - up data on all patients were obtained from the korea national health insurance service database . the median follow - up period was 17.8 months ( range , 0.1 to 172.4 months ) . all statistical analyses were performed using spss ver . 20.0 for windows ( ibm co. , armonk , ny ) . from june 1998 to july 2014 , a total of 358 patients over 85 years old were diagnosed with gc at severance hospital ( seoul , korea ) . for the present analysis , the following patients were excluded ( 1 ) those who had no subsequent follow - up visits after diagnosis , ( 2 ) those who had a significant comorbidity that could affect the mortality , and ( 3 ) those who had been treated at another hospital during the follow - up period . the patients were evaluated in terms of their general information , such as age , sex , and treatment method . the variables investigated also included the macroscopic classification , histological classification , comorbidity , postoperative mortality , and clinical outcome . as categorized by the treatment modality for gc , 81 patients underwent treatment ( treatment group ) , such as an endoscopic resection , surgery , chemotherapy , or radiotherapy , and 89 patients received conservative observation ( conservative group ) . therefore , the patients were divided roughly into two groups : those with macroscopically early gcs ( cancer confined to the mucosa or submucosa ) and those with macroscopically advanced gc ( cancer with invasion extending through the muscularis propria ) . the institutional review board ( irb ) of severance hospital approved this study ( irb approval number : 4 - 2014 - 0464 ) . the chi - square test and fisher exact test were used to compare the clinicopathological characteristics between the treatment - modality groups . follow - up data on all patients were obtained from the korea national health insurance service database . the median follow - up period was 17.8 months ( range , 0.1 to 172.4 months ) . all statistical analyses were performed using spss ver . 20.0 for windows ( ibm co. , armonk , ny ) . the sex or histologic type was similar in the two groups . on the other hand , older age , macroscopically advanced cancer , and upper - middle located cancer were significantly more common in the conservative group ( table 1 ) . in the treatment group , 21 patients underwent er , 48 patients underwent gastrectomy , and 12 patients underwent chemotherapy or radiotherapy . of the 21 patients who received er , 20 had lesions included in the absolute indication and one patient had lesions included in the expanded indication . of the 48 patients who received surgery , 46 underwent a curative gastric resection ( subtotal gastrectomy , n=43 ; total gastrectomy , n=3 ) and two received palliative gastrectomy . the curative resection rate was 18/21 ( 85.7% ) for er and 46/48 ( 95.8% ) for gastrectomy . in the conservative observation group , 38/89 patients ( 42.7% ) refused the recommended treatment . in the overall study cohort , the most common concomitant disease was hypertension ( 32.9% ) . eighty - two patients ( 48.2% ) had one or more comorbid diseases and 37 patients ( 21.8% ) had more than two comorbid diseases . one hundred forty - three patients ( 84.1% ) visited the hospital with symptoms and 27 patients ( 15.9% ) were diagnosed with gc during a health check - up . the most common initial presentation was abdominal pain , which was present in 69 patients ( 40.6% ) . thirty - seven patients ( 21.8% ) had alarm signs ( weight loss , signs and symptoms of upper gastrointestinal bleeding , and anemia ) , and the presence of an alarm sign was significantly more common in the conservative observation group than in the treatment group . on the other hand , a postoperative complication ( bleeding ) occurred in one patient who underwent a gastrectomy ; this patient died three days after surgery . the overall survival rate in the treatment group was significantly higher than that in the conservative group ( fig . furthermore , the disease - specific mortality was significantly lower in the treatment group than in the conservative group ( fig . the 81 patients in the treatment group and the 89 patients in the conservative group were divided into early gc and advanced gc subgroups , as shown in fig . the overall survival rate was significantly higher in the treatment group than in the conservative group . for patients with early gc , the overall survival rate was also significantly higher in the treatment group than in the conservative group ( p < 0.001 ) ( fig . similarly , the disease - specific mortality in the treatment group was significantly lower than that in the conservative group , regardless whether early or advanced gc had been diagnosed ( p < 0.001 ) ( fig . subgroup analysis was performed on the overall survival and disease specific mortality between the conservative observation group who refused the recommended treatment and the treatment group . the overall survival rate of the treatment group was significantly higher than the conservative observation group who refused the recommended treatment and the disease specific mortality rate was significantly lower ( fig . the patients in the treatment group and the conservative observation group who refused the recommended treatment were divided into early gc and advanced gc subgroups . the overall survival rate was significantly higher and the disease - specific mortality rate was significantly lower in the treatment group than in the conservative observation group who refused the recommended treatment , regardless whether early or advanced gc had been diagnosed ( fig . the overall survival rate of the er and surgery group was similar and the disease - specific mortality of the er and surgery group was also similar ( data not shown ) . seven factors ( clinical course , age , sex , histologic type , macroscopic classification , alarm sign , and concomitant disease ) were evaluated by univariate analyses to investigate the associations of the clinicopathological characteristics with the prognosis . significant differences were observed for the clinical course ( p < 0.001 ) , age ( p=0.027 ) , histologic type ( p=0.031 ) , alarm sign ( p < 0.001 ) , and macroscopic classification ( p the same seven factors were then analyzed by multivariate analysis , which revealed the clinical course ( p < 0.001 ) , alarm sign ( p=0.009 ) , and macroscopic classification ( p < 0.001 ) to be independent prognosis factors ( table 3 ) . the sex or histologic type was similar in the two groups . on the other hand , older age , macroscopically advanced cancer , and upper - middle located cancer were significantly more common in the conservative group ( table 1 ) . in the treatment group , 21 patients underwent er , 48 patients underwent gastrectomy , and 12 patients underwent chemotherapy or radiotherapy . of the 21 patients who received er , 20 had lesions included in the absolute indication and one patient had lesions included in the expanded indication . of the 48 patients who received surgery , 46 underwent a curative gastric resection ( subtotal gastrectomy , n=43 ; total gastrectomy , n=3 ) and two received palliative gastrectomy . the curative resection rate was 18/21 ( 85.7% ) for er and 46/48 ( 95.8% ) for gastrectomy . in the conservative observation group , 38/89 patients ( 42.7% ) refused the recommended treatment . in the overall study cohort , the most common concomitant disease was hypertension ( 32.9% ) . eighty - two patients ( 48.2% ) had one or more comorbid diseases and 37 patients ( 21.8% ) had more than two comorbid diseases . one hundred forty - three patients ( 84.1% ) visited the hospital with symptoms and 27 patients ( 15.9% ) were diagnosed with gc during a health check - up . the most common initial presentation was abdominal pain , which was present in 69 patients ( 40.6% ) . thirty - seven patients ( 21.8% ) had alarm signs ( weight loss , signs and symptoms of upper gastrointestinal bleeding , and anemia ) , and the presence of an alarm sign was significantly more common in the conservative observation group than in the treatment group . on the other hand , a postoperative complication ( bleeding ) occurred in one patient who underwent a gastrectomy ; this patient died three days after surgery . the overall survival rate in the treatment group was significantly higher than that in the conservative group ( fig . 1a ) . furthermore , the disease - specific mortality was significantly lower in the treatment group than in the conservative group ( fig . the 81 patients in the treatment group and the 89 patients in the conservative group were divided into early gc and advanced gc subgroups , as shown in fig . the overall survival rate was significantly higher in the treatment group than in the conservative group . for patients with early gc , the overall survival rate was also significantly higher in the treatment group than in the conservative group ( p < 0.001 ) ( fig . similarly , the disease - specific mortality in the treatment group was significantly lower than that in the conservative group , regardless whether early or advanced gc had been diagnosed ( p < 0.001 ) ( fig . subgroup analysis was performed on the overall survival and disease specific mortality between the conservative observation group who refused the recommended treatment and the treatment group . the overall survival rate of the treatment group was significantly higher than the conservative observation group who refused the recommended treatment and the disease specific mortality rate was significantly lower ( fig . the patients in the treatment group and the conservative observation group who refused the recommended treatment were divided into early gc and advanced gc subgroups . the overall survival rate was significantly higher and the disease - specific mortality rate was significantly lower in the treatment group than in the conservative observation group who refused the recommended treatment , regardless whether early or advanced gc had been diagnosed ( fig . the overall survival rate of the er and surgery group was similar and the disease - specific mortality of the er and surgery group was also similar ( data not shown ) . seven factors ( clinical course , age , sex , histologic type , macroscopic classification , alarm sign , and concomitant disease ) were evaluated by univariate analyses to investigate the associations of the clinicopathological characteristics with the prognosis . significant differences were observed for the clinical course ( p < 0.001 ) , age ( p=0.027 ) , histologic type ( p=0.031 ) , alarm sign ( p < 0.001 ) , and macroscopic classification ( p < 0.001 ) ( table 2 ) . the same seven factors were then analyzed by multivariate analysis , which revealed the clinical course ( p < 0.001 ) , alarm sign ( p=0.009 ) , and macroscopic classification ( p < 0.001 ) to be independent prognosis factors ( table 3 ) . as the society ages , clinicians are increasingly being confronted with the challenges of treating elderly patients . in korea , the number of patients diagnosed with gc at extremely old ages has been increasing . several reports have shown that older patients tend to receive less treatment for gcs than younger patients [ 14 - 18 ] . when clinicians make the decision to treat cancer , they consider the cancer stage , the patient s performance status , deterioration of the patient s mental status , and concomitant disease together ; they do not rely on the patient s age alone . generally , the prognosis of elderly patients has been thought to be worse than that of younger patients because of concomitant disease . on the other hand , deaths due to other concomitant diseases amounted to 34%-37% of the total deaths in > 80-year - old patients with gc . investigated patients with gc who were older than 80 years and reported that the survival rate after surgical treatment was significantly higher than that for conservative observation , regardless of the patient s performance status and irrespective of whether his or her mental status had deteriorated . the macroscopic classification of the case ( e.g. , early or advanced cancer ) was an important prognostic factor . treatments are recommended for gc , even for older patients with age - associated comorbidities that are under control . in a study of the natural history of early gc , tsukuma et al . even patients with early gc usually die within 3 years in the absence of treatment . on the other hand , katai et al . reported that when a gastrectomy had been performed safely by specialists , the survival rate of elderly patients with early gc was not significantly different from that of the general population . therefore , the treatment of early gc should not be discouraged in very elderly patients . in this study , patients in the treatment group , those with early gc , and those without an alarm sign showed higher overall survival rates than the others . compared to gastrectomy , er is a less invasive treatment for gc and has many advantages . these advantages include preservation of the stomach , which increases the quality of life and reduces the length of hospitalization compared to gastrectomy . furthermore , er - related complications result from the difficulties encountered when performing the resection endoscopically , which are associated with the tumor size and location , rather than age . several reports have shown that er is a safe and feasible treatment for gc in elderly patients . reported that the results of an endoscopic mucosal resection in patients older than 80 years were outstanding , and were the same as those obtained via gastrectomy . therefore , elderly patients with earlier - stage cancer should receive less - invasive treatments . as the techniques of preoperative and perioperative management have improved , the outcomes of gastric surgery in the elderly have also shown favorable results . similarly , the overall survival rate of the patients in the present study s treatment group was significantly higher than that in the conservatively observed group . in this study , advanced gc accounted for 72.9% of cases . the percentage of patients with advanced cancer was significantly higher in the conservative observation group than in the treatment group . therefore , it is important to recognize cancers at the earlier stage to provide a better prognosis in elderly patients . in a previous study , in the present study , 88 patients ( 51.8% ) did not have any concomitant disease . furthermore , 143 patients ( 84.1% ) presented with symptoms and 37 patients ( 21.8% ) showed an alarm sign . therefore , elderly patients who are being followed up for concomitant disease also need to be checked for gastrointestinal disease . when patients have symptoms , the clinicians need to consider further evaluations . this study was retrospective and could not investigate exactly how the decision was made as to whether to treat the patients or not . in addition , the tnm classification of the patients could not be evaluated because the staging of the patients in the conservative group could not be investigated accurately . in this study , however , the overall survival of the patients with advanced gc was significantly lower than in the early gc chronological age alone should not be used as a strategy of determining if treatment will be administered for gc . patients with early gc or lower - risk preexisting comorbidities should not be discouraged from treatment , even if they are older than 85 years .