Prospective investigation of tumor markers and risk assessment in early cancer screening.
BACKGROUND
Many researchers have reported that tumor marker diagnosis may not be useful in the early detection of cancer. However, the authors proposed a new diagnostic system using a tumor marker combination assay.


METHODS
The authors screened an asymptomatic population (2126 subjects) in Japan for early cancer over a 2-year period (1984-1986) using this tumor marker combination assay. The serum tumor marker combination assay data were analyzed: tumor-specific tumor markers (carcinoembryonic antigen, carbohydrate 19-9, heat-stable alkaline phosphatase, and tissue polypeptide antigen), tumor-associated tumor markers (ferritin, the ratio of ferritin to serum iron, immunosuppressive acidic protein, sialic acid), and growth-related tumor markers (alkaline phosphatase isoenzymes, ribonuclease). The tumor growth levels of the subjects were assessed by the tumor marker combination assay and classified into five tumor stages (Stage I, tumorfree; Stages II-III, precancer; Stage IV, preclinical cancer; Stage V, suggestive of cancer weighing over 1 g). The follow-up period was 5-7 years.


RESULTS
The percentage of subjects in tumor stages IV and V increased with age, whereas the percentage in tumor stages II and III decreased. The distribution of screenees within each tumor stage was as follows: I, 0.1%; II, 11.8%; III, 58.8%; IV, 24.8%; V, 4.6%. The rate of incidence of cancer for Stages V, VI, III, II and I was 29.5% (28 of 95), 2.7% (14 of 528), 0.7% (9 of 1251), 0.4% (1 of 250), and 0 (0 of 2), respectively.


CONCLUSIONS
Our tumor stage classification can adequately assess the risk of cancer developing in apparently healthy persons.
Kobayashi
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T
Asia Medical Center, Saitama, Japan.
Kawakubo
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D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D000951:Antigens, Neoplasm / Q000097:blood; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D005260:Female; D005293:Ferritins / Q000097:blood; D005500:Follow-Up Studies; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D007564:Japan; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D019158:N-Acetylneuraminic Acid; D009363:Neoplasm Proteins / Q000097:blood; D009367:Neoplasm Staging; D009369:Neoplasms / Q000097:blood / Q000473:pathology / Q000517:prevention & control*; D010455:Peptides / Q000097:blood; D011230:Precancerous Conditions / Q000097:blood / Q000473:pathology / Q000517:prevention & control; D011446:Prospective Studies; D012260:Ribonucleases / Q000097:blood; D012794:Sialic Acids / Q000097:blood; D019396:Tissue Polypeptide Antigen
D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D007527:Isoenzymes; D009363:Neoplasm Proteins; D010455:Peptides; D012794:Sialic Acids; D019396:Tissue Polypeptide Antigen; C030193:immunosuppressive acidic protein; D005293:Ferritins; D012260:Ribonucleases; D000469:Alkaline Phosphatase; D019158:N-Acetylneuraminic Acid