[Sister chromatid exchange (SCE) in lymphocytes of patients with cancer of the cervix uteri]. 
The frequency of spontaneous and Mitomycin C (MMC)-induced sister chromatid exchange (SCE) was investigated in peripheral lymphocytes of 31 untreated patients with cervical cancer (stage 0:7 cases, stage I:9 cases, stage II:6 cases and stage III:9 cases), as well as of 7 untreated patients with myoma uteri and 16 healthy women.  Factors affecting SCE frequency were also investigated.  Age, smoking and atomic bomb exposure did not influence SCE frequency.  However, a family history of cancer significantly increased MMC-induced SCE frequency in the cancer group.  The mean spontaneous SCE frequency in the cancer group (9.83 +/- 1.74) was significantly higher than that in the myoma group (8.13 +/- 0.81) and healthy women (7.59 +/- 0.85).  The mitomycin C-induced SCE frequency was also higher in the cancer group.  Spontaneous and MMC-induced SCE frequency gradually increased with the progression of cervical cancer.  All chromosome groups equally contributed to the increased SCE frequency in the cancer group.  These results suggest that deoxyribonucleic acid of all chromosomes is damaged in patients with cervical cancer.