since 1983 , as the leading cause of death , cancer has become a major public health concern in korea . annually , over 190,000 patients are newly diagnosed with cancer in korea , and one out of four deaths is due to cancer . although the cancer registration system in korea is very efficient and can provide nationwide cancer statistics within a relatively short time , at least a 2-year lag is still required for accurate data collection and compilation . to plan and apply a cancer control program , it is important to assess the number of new cases and deaths that are expected to occur during the current year . in this report , we provide the projected cancer incidence and mortality ratio based on the data up to 2009 . the korean ministry of health and welfare initiated a nationwide , hospital - based cancer registry ( the korea central cancer registry [ kccr ] ) in 1980 . the details of the history , objectives , and activities of the kccr have been documented elsewhere . incidence data from 1999 to 2009 were obtained from the korea national cancer incidence database ( knci db ) . cancer cases were classified according to the international classification of diseases for oncology , 3rd edition   and converted according to the international classification of diseases , 10th edition ( icd-10 ) . the cancer sites included in this report are ( i ) all cancers combined and ( ii ) the 22 most common cancers : lip , month , and pharynx ( c00-c14 ) , esophagus ( c15 ) , stomach ( c16 ) , colon and rectum ( c18-c20 ) , liver and intrahepatic bile duct ( liver ) ( c22 ) , gallbladder and other parts of biliary tract ( gallbladder ) ( c23-c24 ) , pancreas ( c25 ) , lung and bronchus ( lung ) ( c33-c34 ) , breast ( c50 ) , uterine cervix ( c53 ) , uterine corpus ( c54 ) , ovary ( c56 ) , prostate ( c61 ) , testis ( c62 ) , kidney ( c64 ) , bladder ( c67 ) , brain and central nervous system ( c70-c72 ) , thyroid ( c73 ) , hodgkin lymphoma ( c81 ) , non - hodgkin lymphoma ( c82-c85 , c96 ) , multiple myeloma ( c90 ) , leukemia ( c91-c95 ) , and all others . the mid - year population on july 1 of the respective year was applied when computing the incidence and deaths . due to the time required for data collection and analysis , incidence and mortality data are available is usually 2 - 3 years behind the current year . as such , we projected the expected number of new cancer cases and deaths in korea in the current year to provide an estimate of the current cancer burden . linear regression models   were used to assess the time trend and the projection of rates . based on the observed cancer incidence data , a linear regression model was fitted to the age - specific rates by 5-year age group against observed years . from the projected age - specific rates in 2012 , the estimated number of cancer cases was calculated by multiplying the rates by 2012 's projected age - specific population size . for thyroid and prostate cancer , which showed significant curvilinear trends , we used a square root transformation when fitting a linear regression model and converted the predicted values back to the original scale . to estimate the number of cancer deaths in 2012 , we first ran a joinpoint regression model on the data for 1993 - 2010 to detect the year of significant changes in the trend of cancer mortality by sex and cancer site . a joinpoint regression describes changes in data trends by connecting several different line segments on a log scale at " joinpoints . " this analysis was performed using the joinpoint software ( version 3.3 , http://srab.cancer.gov/joinpoint ) from the surveillance research program of the national cancer institute in the usa . after identifying the year of significant trend changes using joinpoint regression analysis , a simple linear regression model was fitted to the last line segment to estimate age - specific cancer mortality rates in 2012 . similar to the method used for the projection of cancer incidence , the number of new deaths was then projected by multiplying the age - specific cancer mortality rates by 2012 's projected age - specific population . we summarized the results using the crude rates ( crs ) and age - standardized rates ( asrs ) of cancer incidence and mortality . the asrs were standardized using the world health organization ( who ) world standard population . table 1 presents the estimated number of new cancer cases and deaths during 2012 in korea by sex and cancer site . table 2 presents the estimated crs and asrs of cancer incidence in 2012 by sex and cancer site . the crs of all sites combined in males and females respectively in 2012 are projected to be 465.6 and 459.7 per 100,000 , and the asrs of all sites combined are projected to be 345.1 and 300.9 per 100,000 . in males , the five leading primary sites of cancer are expected to be the stomach ( cr , 86.8 ; asr , 63.2 ) , colon and rectum ( cr , 77.4 ; asr , 56.7 ) , lung ( cr , 62.9 ; asr , 46.6 ) , liver ( cr , 49.5 ; asr , 35.6 ) , and prostate ( cr , 43.4 ; asr , 32.5 ) , accounting for 68.7% of all newly diagnosed cancers in 2012 . in females , the most common cancer sites are expected to be thyroid ( cr , 153.4 ; asr , 109.4 ) , breast ( cr , 64.6 ; asr , 44.1 ) , colon and rectum ( cr , 49.5 ; asr , 29.5 ) , stomach ( cr , 41.1 ; asr , 24.7 ) , lung ( cr , 26.6 ; asr , 14.7 ) , and liver ( cr , 17.1 ; asr , 10.0 ) , accounting for 76.7% of all newly diagnosed cancers ( fig . thyroid cancer alone is projected to account for 33.4% ( 38,863 cases ) of incident cases in females in 2012 . table 3 presents the most common cancer sites expected in 2012 by sex and age group . leukemia and thyroid cancer are projected to be the most common forms of cancer in both sexes for the 0 - 14 and 15 - 34 age groups . gastric cancer is predicted to be the most common cancer in males 35 - 64 years of age , whereas lung cancer is predicted to be more frequent for malese 65 years of age . thyroid cancer is predicted to be the most common cancer for females 35 - 64 years of age , whereas colorectal cancer is predicted to be the most common cancer for females 65 years of age . 2 shows the age - specific incidence rates of the selected cancers for men and women in 2012 . the projection indicates that the incidence of gastric , lung , liver , and colorectal cancers will increase gradually with age . in women , the age - specific incidence rates of breast and thyroid cancer will increase with age until the 5th and 6th decades of life , and then level off . it is estimated that 73,313 cancer deaths will occur in korea during 2012 ( table 1 ) . the crs of all sites combined in 2012 respectively for males and females are projected to be 178.5 and 110.4 per 100,000 , and the asrs of all sites combined are expected to be 135.8 and 59.0 per 100,000 ( table 4 ) . in 2012 , the five leading cancer sites causing mortality in males are predicted to be lung ( cr , 46.5 ; asr , 34.4 ) , liver ( cr , 32.2 ; asr , 23.5 ) , stomach ( cr , 22.2 ; asr , 16.4 ) , colon and rectum ( cr , 18.3 ; asr , 13.7 ) , and pancreas ( cr , 9.6 ; asr , 7.1 ) . during the same time period , in females , lung cancer ( cr , 17.2 ; asr , 8.7 ) is projected to be the leading cancer site causing mortality , followed by cancers of the colon and rectum ( cr , 14.0 ; asr , 7.1 ) , stomach ( cr , 12.1 ; asr , 6.1 ) , liver ( cr , 11.0 ; asr , 6.0 ) , and pancreas ( cr , 8.8 ; asr , 4.5 ) . 3 shows the age - specific predicted mortality rates of the selected cancers for males and females in 2012 . when examined by age , korean males > 60 years of age are expected to have the highest mortality rates from liver cancer , followed by lung cancer . in contrast , korean females > 55 years of age are expected to have the highest mortality rates from breast cancer , followed by lung cancer . table 1 presents the estimated number of new cancer cases and deaths during 2012 in korea by sex and cancer site . table 2 presents the estimated crs and asrs of cancer incidence in 2012 by sex and cancer site . the crs of all sites combined in males and females respectively in 2012 are projected to be 465.6 and 459.7 per 100,000 , and the asrs of all sites combined are projected to be 345.1 and 300.9 per 100,000 . in males , the five leading primary sites of cancer are expected to be the stomach ( cr , 86.8 ; asr , 63.2 ) , colon and rectum ( cr , 77.4 ; asr , 56.7 ) , lung ( cr , 62.9 ; asr , 46.6 ) , liver ( cr , 49.5 ; asr , 35.6 ) , and prostate ( cr , 43.4 ; asr , 32.5 ) , accounting for 68.7% of all newly diagnosed cancers in 2012 . in females , the most common cancer sites are expected to be thyroid ( cr , 153.4 ; asr , 109.4 ) , breast ( cr , 64.6 ; asr , 44.1 ) , colon and rectum ( cr , 49.5 ; asr , 29.5 ) , stomach ( cr , 41.1 ; asr , 24.7 ) , lung ( cr , 26.6 ; asr , 14.7 ) , and liver ( cr , 17.1 ; asr , 10.0 ) , accounting for 76.7% of all newly diagnosed cancers ( fig . thyroid cancer alone is projected to account for 33.4% ( 38,863 cases ) of incident cases in females in 2012 . table 3 presents the most common cancer sites expected in 2012 by sex and age group . leukemia and thyroid cancer are projected to be the most common forms of cancer in both sexes for the 0 - 14 and 15 - 34 age groups . gastric cancer is predicted to be the most common cancer in males 35 - 64 years of age , whereas lung cancer is predicted to be more frequent for malese 65 years of age . thyroid cancer is predicted to be the most common cancer for females 35 - 64 years of age , whereas colorectal cancer is predicted to be the most common cancer for females 65 years of age . 2 shows the age - specific incidence rates of the selected cancers for men and women in 2012 . the projection indicates that the incidence of gastric , lung , liver , and colorectal cancers will increase gradually with age . in women , the age - specific incidence rates of breast and thyroid cancer will increase with age until the 5th and 6th decades of life , and then level off . it is estimated that 73,313 cancer deaths will occur in korea during 2012 ( table 1 ) . the crs of all sites combined in 2012 respectively for males and females are projected to be 178.5 and 110.4 per 100,000 , and the asrs of all sites combined are expected to be 135.8 and 59.0 per 100,000 ( table 4 ) . in 2012 , the five leading cancer sites causing mortality in males are predicted to be lung ( cr , 46.5 ; asr , 34.4 ) , liver ( cr , 32.2 ; asr , 23.5 ) , stomach ( cr , 22.2 ; asr , 16.4 ) , colon and rectum ( cr , 18.3 ; asr , 13.7 ) , and pancreas ( cr , 9.6 ; asr , 7.1 ) . during the same time period , in females , lung cancer ( cr , 17.2 ; asr , 8.7 ) is projected to be the leading cancer site causing mortality , followed by cancers of the colon and rectum ( cr , 14.0 ; asr , 7.1 ) , stomach ( cr , 12.1 ; asr , 6.1 ) , liver ( cr , 11.0 ; asr , 6.0 ) , and pancreas ( cr , 8.8 ; asr , 4.5 ) . 3 shows the age - specific predicted mortality rates of the selected cancers for males and females in 2012 . when examined by age , korean males > 60 years of age are expected to have the highest mortality rates from liver cancer , followed by lung cancer . in contrast , korean females > 55 years of age are expected to have the highest mortality rates from breast cancer , followed by lung cancer . this report provides the estimated nationwide cancer incidence and mortality in korea for the current year . a total of 234,727 new cancer cases and 73,313 cancer deaths are expected in korea during 2012 . in korean males , gastric , colorectal , lung , liver , and prostate cancers are estimated to have the highest rates of incidence , while lung , liver , gastric , colorectal , and pancreatic cancers are estimated to be the most common causes of cancer - related deaths . in korean females , thyroid , breast , colorectal , gastric , and lung cancer are estimated to have the highest rates of incidence , while lung , colorectal , stomach , liver , and pancreas cancers are estimated to be the most common causes of cancer - related deaths . cancer has become an important public health concern in korea , and as the population continues to age , the cancer burden will continue to increase . the estimated cancer statistics of the current year given in this report represent an important resource to plan and evaluate cancer - control programs . the estimates in this report , however , are projected numbers based on statistical models and may vary from year to year ; hence , these estimates should be used with caution .