BACKGROUND: The incidence of double primary neoplasms has increased in recent decades. The etiologies and epidemiologies of double primary neoplasms are under investigation, and relationships between some cancers are well established. A group of patients with double primary cancers was studied to determine the relationships between certain cancers. METHODS: From November 1982 to September 1993, 48 patients with colorectal cancer accompanied by cancer of another organ (double primary cancers) were treated here. The male-to-female ratio was 31 to 17. According to Warren's definitions, the patients were classified into two groups: synchronous and metachronous. Data collection was done on the basis of locations, pathological staging and interval between cancers. RESULTS: Among the 48 patients, extracolonic cancers were mainly found in the cervix (8), stomach (7), prostate (5), lung (5), urinary bladder (4), and breast (4). In the female patients, 88.2% (15/17) of extracolonic cancers were in the female reproductive organs. In male patients, 45% (14/31) of extracolonic cancers were GI tract neoplasms, and 35.5% (11/31) were cancers of the GU tract. Nearly half of the patients expired within two years after diagnosis of the second primary cancer. CONCLUSIONS: Cancers of the cervix, stomach, prostate, lung, urinary bladder and breast may have some etiologic factors in common with that of colorectuim. Thus, attention should be paid to these sites during the period of post-operative follow-up of the first primary cancer.
BACKGROUND: The incidence of double primary neoplasms has increased in recent decades. The etiologies and epidemiologies of double primary neoplasms are under investigation, and relationships between some cancers are well established. A group of patients with double primary cancers was studied to determine the relationships between certain cancers. METHODS: From November 1982 to September 1993, 48 patients with colorectal cancer accompanied by cancer of another organ (double primary cancers) were treated here. The male-to-female ratio was 31 to 17. According to Warren's definitions, the patients were classified into two groups: synchronous and metachronous. Data collection was done on the basis of locations, pathological staging and interval between cancers. RESULTS: Among the 48 patients, extracolonic cancers were mainly found in the cervix (8), stomach (7), prostate (5), lung (5), urinary bladder (4), and breast (4). In the female patients, 88.2% (15/17) of extracolonic cancers were in the female reproductive organs. In male patients, 45% (14/31) of extracolonic cancers were GI tract neoplasms, and 35.5% (11/31) were cancers of the GU tract. Nearly half of the patients expired within two years after diagnosis of the second primary cancer. CONCLUSIONS:Cancers of the cervix, stomach, prostate, lung, urinary bladder and breast may have some etiologic factors in common with that of colorectuim. Thus, attention should be paid to these sites during the period of post-operative follow-up of the first primary cancer.