The national cancer screening program was found to have failed to detect some 7 , 000 cases last year , a lawmaker said yesterday . According to the Ministry for Health , Welfare and Family Affairs , a total of 7 , 124 people developed cancer last year even though they had tested negative through free checkups in the previous year , said Rep . Lee Ae - joo of the ruling Grand National Party . Lee pointed out that the cases undetected two years ago include not only " unavoidable ones " but also misdiagnoses , which may be caused by flawed equipment , diagnostic misjudgment or price competition among testing institutions . Of the cancer victims that received the national cancer screening in 2007 , 2 , 384 were diagnosed with breast cancer last year , 2 , 147 with stomach cancer , 2 , 101 with colon cancer , 354 with cervical cancer and 108 with liver cancer . Based on the nation ` s medical insurance plan , the government supports free checkups for the five cancers , which are the most common types in Korea . " The survey results reflect only the cases conducted by the government ` s five - cancer screening program . When including those by private institutions and other types of cancer cases , the extent of the damages would be far greater , " said Lee , who is also a member at the parliamentary committee on health , welfare and family affairs . " The government should implement stricter monitoring on hospitals and private clinics that are conducting cancer screening . " ( jylee @ heraldm . com ) By Lee Ji - yoon